Aqueous phase hexylchloroformate derivatization and solid phase microextraction: Determination of benzoylecgonine in urine by...
TY - JOUR. T1 - Aqueous phase hexylchloroformate derivatization and solid phase microextraction. T2 - Determination of benzoylecgonine in urine by gas chromatography-quadrupole ion trap mass spectrometry. AU - Hall, Brad J.. AU - Parikh, Aashish R.. AU - Brodbelt, Jennifer S.. PY - 1999/5. Y1 - 1999/5. N2 - A derivatization/solid phase microextraction (SPME) method for the determination of benzoylecgonine in urine was developed. The derivatization is conducted directly in 1 mL of urine while sonicating for 3 min with 12 μL of hexyl chloroformate and 70 μL of a mixture containing acetonitrile:water:hexanol:2-dimethylaminopyridine (5:2:2:1 v/v), yielding benzoylecgonine hexyl ester (BHE) as the product. After the 3 min period, an aliquot of 250 μL is transferred to a vial for SPME. After the desired extraction time the 100 μm polydimethylsiloxane SPME fiber was transferred to the GC-MS for separation and analysis with a quadrupole ion trap mass spectrometer. The hexyl chloroformate ...
Characterization and optimization of a high surface area-solid phase microextraction sampler for the collection of trace level...
Title: Characterization and Optimization of a High Surface Area-Solid Phase Microextraction Sampler for the Collection of Trace Level Volatile Organic Compounds in the Field Shannon Scott McDonald, Master of Science in Public Health, 2006 Directed By: Gary Hook, CDR, USN Assistant Professor, Department of Preventive Medicine and Biometrics A prototype rapid, high volume air sampling device based on Solid Phase Microextraction (SPME) has been developed for the collection of trace level volatile organic compounds (VOCs). The High Surface Area-Solid Phase Microextraction (HSA- SPME) device contains ten times more polymer than traditional SPME fibers and is uniquely designed to optimize compound uptake at higher flow rates. This study evaluated the extraction efficiency at six air sampling flow rates ranging from 0.1 L/min to 10 L/min and compared total compound extraction at the two extreme flow rates. A 10 ppbv concentration of 39 volatile organic compounds was used. ...
Extending the Limits of Solid Phase Microextraction by Shilpi Chopra
Solid phase microextraction (SPME) is a solventless extraction technique that combines sample preparation and sample introduction into a gas chromatograph into a single step. For the past 20 years, solid-phase micro-extraction (SPME) has been used in numerous fields such as: food analysis, including juices, alcohols fruits and vegetables for volatiles, aroma, caffeine, fatty esters, environmental applications including volatile organic contaminants, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenols, pesticides, steroids, herbicides, acid/neutral/base compounds, and organometallic compounds from water, air, soil, sludge, and sediment samples and in biomedical analysis. This work demonstrates the extension of the limitations of SPME with respect to extraction and analysis of a) extension of headspace SPME to larger polycyclic aromatic hydrocarbons from fish oil b) less volatility analytes, combination of SPME-Gas Chromatograph -Mass Spectrometer -Mass Spectrometer (SPME-GC-MS-MS) to
Characterization of volatile compounds of Daucus crinitus Desf. Headspace Solid Phase Microextraction as alternative technique...
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
The use of solid phase microextraction for metabolomic analysis of non-small cell lung carcinoma cell line (A549) after...
Use of solid phase microextraction (SPME) for cell culture metabolomic analysis allows for the attainment of more sophisticated data from in vitro cell cultures. Moreover, considering that SPME allows the implementation of multiple extractions from the same sample due to its non/low-depletive nature, time course studies using the same set of samples are thus facilitated via this method. Such an approach results in a reduction in the number of samples needed for analysis thus eliminates inter-batch variability related to biological variation occurring during cell culturing. The current work aims to demonstrate the capability of SPME for measurements of combretastatin A4 (CA4) effectiveness on non-small cell cancer cell line. A cultivation protocol was established in the 96-well plate, and a fiber format of SPME was selected for metabolite extraction. The extracellular metabolic pattern of cells was changed after administration of the tested drug. This suggests pharmacological activity of the ...
Monitoring of priority pesticides using SPME (solid phase microextraction) in river water from Greece | Water Supply | IWA...
A solid phase microextraction (SPME) method was applied for the extended monitoring survey of priority pesticides for the European Union, for 12 months, in Kala
Field Sampling for Pesticides, Using Solid Phase Microextraction/Capillary GC on Environmental XPRT
Article Field Sampling for Pesticides, Using Solid Phase Microextraction/Capillary GC. An SPME portable field sampler can be used to extract analytes from samples in the field, then store them for up to 3 days, or longer, before performing the analys...
Investigation of Early Death-Induced Changes in Rat Brain by Solid Phase Microextraction via Untargeted High Resolution Mass...
Analysis of brain samples obtained postmortem remains a standard approach in neuroscience, despite often being suboptimal for inferring roles of small molecules in the pathophysiology of brain diseases. Sample collection and preservation further hinders conclusive interpretation of biomarker analysis in autopsy samples. We investigate purely death-induced changes affecting rat hippocampus in the first hour of postmortem interval (PMI) by means of untargeted liquid chromatography- mass spectrometry-based metabolomics. The unique possibility of sampling the same brain area of each animal both in vivo and postmortem was enabled by employing solid phase microextraction (SPME) probes. Four millimeter probes coated with mixed mode extraction phase were used to sample awake, freely roaming animals, with 2 more sampling events performed after death. Significant changes in brain neurochemistry were found to occur as soon as 30 min after death, further progressing with increasing PMI, evidenced by ...
Analysis of the volatile chemical markers of explosives using novel solid phase microextraction coupled to ion mobility...
Ion mobility spectrometry (IMS) is routinely used in screening checkpoints for the detection of explosives and illicit drugs but it mainly relies on the capture of particles on a swab surface for the detection. Solid phase microextraction (SPME) has been coupled to IMS for the preconcentration of ex …
Use of gas chromatography-mass spectrometry/solid phase microextraction for the identification of MVOCs from moldy building...
article{191ea318-159e-43da-9392-05ee7bf33a0d, author = {Wady, Loay and Bunte, Annicka and Pehrson, Christina and Larsson, Lennart}, issn = {1872-8359}, language = {eng}, number = {3}, pages = {325--332}, publisher = {Elsevier}, series = {Journal of Microbiological Methods}, title = {Use of gas chromatography-mass spectrometry/solid phase microextraction for the identification of MVOCs from moldy building materials.}, url = {http://dx.doi.org/10.1016/S0167-7012(02)00190-2}, volume = {52}, year = {2003 ...
Development of Heated Headspace Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry for Chemical Profiling of...
As submitted by the proposer: Chemical forensics is a nascent field that collects and attributes chemical information of physical evidence to their sources. Ideally, from a chemical forensic analysis, one can identify chemical signatures of physical evidence and use them to classify or trace the source of it. We propose to use heated headspace solid phase microextraction coupled to gas chromatography/mass spectrometry (HHS-SPME-GC/MS) as an analytical platform for the collection of chemical signatures of physical evidence.
VOLATILE COMPOUNDS OF LITHRAEA CAUSTICA (LITRE) DETERMINATED BY SOLID PHASE MICRO-EXTRACTION (SPME)
GARBARINO, JUAN A et al. VOLATILE COMPOUNDS OF LITHRAEA CAUSTICA (LITRE) DETERMINATED BY SOLID PHASE MICRO-EXTRACTION (SPME). Bol. Soc. Chil. Quím. [online]. 2002, vol.47, n.4, pp.567-569. ISSN 0366-1644. http://dx.doi.org/10.4067/S0366-16442002000400030.. The head space of the aerial parts of Lithraea caustica was analyzed by Solid Phase Micro-Extraction (SPME) technique, obtaining as main volatile compounds the monoterpenes, myrcene, a -pinene, , p-cymene and limonene, as well as the sesquiterpene caryophylene.. Palabras clave : Lithraea caustica; Anacardiaceae; Solid Phase Micro-Extraction; head space components; monoterpenes, sesquiterpenes. ...
Strategies for the Direct Coupling of Solid Phase Microextraction to Mass Spectrometry
In recent years, advances in direct sample to mass spectrometry (MS) techniques have allowed for the application of these methods towards quantitative analysis in complex matrices such as biofluids and tissue. However, the predictable limitations of these technologies, such as ionization suppression, poor sensitivity at trace levels, and narrow linear dynamic range, have been the driving force toward the development of methods that efficiently integrate sampling, sample cleanup, and analyte collection and ionization. In this context, the direct interface of microextraction technologies and MS has undoubtedly revolutionized the speed, efficacy, and robustness with which complex matrices can be scrutinized. In this thesis, numerous strategies recently developed for the direct and efficient coupling of Solid Phase Micro Extraction (SPME) and MS are presented towards the analysis of complex matrices. Aiming to supply a range of technologies suited for diverse applications, different SPME geometries ...
Determination of Signature Volatile Odor Chemicals Emanating from Nove by Jessica S. Brown
Human scent, or the volatile organic compounds (VOCs) produced by an individual, has been recognized as a biometric measurement because of the distinct variations in both the presence and abundance of these VOCs between individuals. In forensic science, human scent has been used as a form of associative evidence by linking a suspect to a scene/object through the use of human scent discriminating canines. The scent most often collected and used with these specially trained canines is from the hands because a majority of the evidence collected is likely to have been handled by the suspect. However, the scents from other biological specimens, especially those that are likely to be present at scenes of violent crimes, have yet to be explored. Hair, fingernails and saliva are examples of these types of specimens.
In this work, a headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) technique was used for the identification of VOCs from hand odor, hair, fingernails and
Fettsäureethylester als Marker exzessiven Alkoholkonsums
The current doctoral thesis presents the development of an analytical procedure for the quantitative analysis of fatty acid ethyl esters (FAEE) in hair and in skin surface lipids using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) as well as a method based on high-performance liquid chromatography with photodiode array detection (HPLC-DAD) to determine squalene concentrations in lipid extracts. The results obtained from analysis of samples from different alcohol consuming groups showed that FAEE are suitable markers for long-term alcohol misuse. Concerning sensitivity and specifity they are at least as good as other commonly used markers like GGT, CDT or MCV. The following provisional cut-off values were established: for chronically excessive alcohol consumption, the sum of the four FAEE (ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) found in the highest mean concentrations should be , 1 ng/mg in hair; for non-drinkers, ...
Metabolomic applied to omalizumab effect in severe asthmatics - a preliminary result | Clinical and Translational Allergy |...
Case report: We present the case of a 48 year old woman, with severe persistent allergic asthma, despite level 4 (GINA) medical treatment, who initiated omalizumab in order to control her nocturnal symptoms and her frequent unscheduled medical visits. Before treatment and at 12 weeks: clinical evaluation with ACT was registered; lung function, FeNO, IgE and eosinophils were measured. Two-dimensional gas chromatography (GC ´GC-ToFMS) combined with headspace solid phase microextraction (HS-SPME) was applied to the untargeted study of the volatile metabolomic urine profile. ...
Solid Phase Microextraction (SPME) Literature from Supelco | China-Mainland | Sigma-Aldrich
Product guides, articles, and application notes describing the use of SPME products in sample preparation and chromatographic analysis.
Analysis of microvolatiles in brandy: relationship between methylketone concentration and Cognac age - Watts - 2003 - Journal...
Headspace solid phase microextraction and gas chromatography/mass spectrometry were used to identify and quantify four odd-numbered methylketones in commercial Cognac brandies. These ketones are in part responsible for the desirable and complex characteristic called rancio charentais or Cognac rancio which is found in grape brandies aged in oak barrels for several decades. The ketones 2-heptanone, 2-nonanone, 2-undecanone and 2-tridecanone form through β-oxidation and decarboxylation of long-chain fatty acids originating from yeast metabolism. The concentrations of these ketones increased with Cognac age classification in the 42 brandies analysed, and 2-heptanone was present at the highest concentration in most samples. The average concentrations and rates of formation decreased with increasing chain length. Total concentrations ranged from 21 to 328 µg l−1. The esters propyl octanoate and ethyl octanoate followed the same trend as the methylketones and appear to play an additional role ...
Switchable solvent-based liquid phase microextraction of copper(II): optimization and application to environmental samples |...
A switchable solvent-based liquid phase microextraction (SS-LPME) procedure has been established for the preconcentration of copper prior to its determination by microsampling flame atomic absorption spectrometry (FAAS). Triethylamine (TEA) was adopted for the study as a green and cheap switchable solvent. The Cu(II)-1-(2-pyridylazo)-2-naphthol (PAN) complex was extracted into the TEA phase by converting the protonated carbonate (P-TEA-C) to TEA. The experimental conditions have been comprehensively studied and optimized. The limit of detection (LOD) and repeatability (RSD%) of the method were 1.80 mu g L-1 and 3.8%, respectively, and its accuracy was assessed against certified reference materials (TMDA-64.2 fortified water, TMDA-53.3 fortified water, TMDA-51.3 fortified water, 1573a tomato leaves, INCT-OBTL-5 oriental basma tobacco leaves and NCS ZC 8100 2b human hair), and by addition-recovery tests. The SS-LPME-FAAS method was also applied for the determination of trace amounts of copper in ...
HS-SPME Archives | Cannabis Industry Journal
Headspace (HS), Solid Phase Microextraction of Headspace (HS-SPME) or Split/Splitless Injection (SSI) are viable techniques and have advantages and disadvantages. While SPME can be performed by either direct immersion with the sample or headspace sampling, HS-SPME is considered the most effective technique since this approach eliminates the complex oil matrix. Likewise, conventional HS also targets volatiles that include the terpenes, leaving the high molecular weight oils and cannabinoids behind (Figure 1). SSI eliminates the complexity of a HS or SPME concentrator/autosampler, however, sensitivity and column lifetime become limiting factors to high throughput, since the entire sample is introduced to the inlet and ultimately the column.. The GC capillary columns range from thicker film, mid-polarity (Rxi-624sil MS for instance) to thinner film, non-polar 100% polysiloxane-based phases, such as an Rxi-1ms. A thicker film provides the best resolution among the highly volatile, early eluting ...
SPME Fiber Assemblies - SPME Fibers and Holders | Sigma-Aldrich
By controlling the polarity and thickness of the coating on the fiber, maintaining consistent sampling time, and adjusting several other extraction parameters, an analyst can ensure highly consistent, quantifiable results from low concentrations of analytes. The original SPME fibers were manufactured with 24 gauge needles, and these continue to work well for manual sampling. Fibers with 23 gauge needles are highly recommended for use with autosamplers, and for the Merlin Microseal® system as well as other septum-less seals.
Forschungsbericht ebergeruch fin2
Anders, S., and W. Huber. 2010. Differential expression analysis for sequence count data. Genome Biol 11: R106. Benjamini, Y., and Y. Hochberg. 1995. Controlling the false discovery rate: A practical and powerful approach to multiple testing. J R Stat Soc Series B 57: 289-300. Bracher-Jakob, A. 2000. Jungebermast in forschung und praxis. Arbeit im Auftrag der Eidgenössischen Forschungsanstalt für Nutztiere, 1725 Posieux, unter Leitung von Duijvesteijn, N. et al. 2010. A genome-wide association study on androstenone levels in pigs reveals a cluster of candidate genes on chromosome 6. Bmc Genetics 11. Fischer, J. et al. 2011. Development of a candidate reference method for the simultaneous quantitation of the boar taint compounds androstenone, 3alpha-androstenol, 3beta- androstenol, skatole, and indole in pig fat by means of stable isotope dilution analysis headspace solid-phase microextraction gas chromatography/mass spectrometry. analytical chemistry 83: 6785-6791. Gregersen, V. R. et al. ...
COMPARISON OF MICRODIALYSIS WITH SOLID-PHASE MICROEXTRACTION FOR IN VIVO STUDY
Although microdialysis (MD) and solid-phase microextraction (SPME) are widely used sampling techniques, a comparison study has not been performed to date. The goal of the research presented was not only to address this issue but also to develop new analytical methods that were more suitable for in vivo study using MD and SPME. A new calibration method called kinetic microdialysis was developed for in vivo sampling. Two MD probes with different flow rates were simultaneously inserted into the symmetric parts of sampling system. A simple empirical equation was proposed to calculate the analyte concentrations in the sample matrix using two different dialysate concentrations. Several factors that influenced the correction factor in this equation were discussed. An excellent correlation was observed between the calculated and theoretical value. This method was subsequently applied for in vivo sampling, for the measurement of pesticide allocation in the different leaves of a jade plant (Crassula ...
uniten.edu.my
1. Chai Mee Kin and Tan Guan Huat. Comparison of different types of coating in headspace solid-phase microextration for the analysis of pesticide residues in vegetables and fruits. 2008. Malaysian Journal of Analytical Science. Vol 12(2). 444-450. 2. Chai Mee Kin, Tan Guan Huat and Asha Kumari. Application of solid-phase microextraction for the determination of pesticides in vegetables samples by gas chromatography with an electron capture detector. 2008. Malaysian Journal of Analytical Science, Vol 12, No 1, Pg 1-9. 3. Chai Mee Kin, Tan Guan Huat and Asha Kumari. Headspace solid- phase microextraction in combination with gas chromatography-mass spectrometry for the rapid screening of pesticide residues in vegetables and fruits. 2007. Malaysian Journal of Chemistry. Vol 9, No. 1, Pg 018-023. 4. Chai Mee Kin, Tan Guan Huat and Asha Kumari. Method development of determination of pesticide residues in vegetables and fruits by using solid-phase microextraction. 2006. Malaysian Journal of Chemistry. ...
Determination of 1,8 Cineole in Fresh Rosemary and Sage Leaves by Solid-phase Microextraction and Gas Chromatography/Mass...
Determination of 1,8 Cineole in Fresh Rosemary and Sage Leaves by Solid-phase Microextraction and Gas Chromatography/Mass Spectrometry
US7178414B1 - Automation of liquid phase microextraction - Google Patents
A method and apparatus for automatically performing liquid microextraction on liquid samples includes the steps of controlling movement of a syringe between a cleaning station, a sample station containing a plurality of discrete sample vials and an instrument injector station. Movement of the syringe is controlled automatically for cleaning the syringe, obtaining a sample of each sample in each discrete sample vial, one at a time, and injecting the collected sample into the instrument injector, and then repeating the sequence steps for all discreet samples.
Volatile profiling reveals intracellular metabolic changes in Aspergil by Ludmila V. Roze, Anindya Chanda et al.
Background: Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes.
Results: Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine); we also
Phytochemical study of the headspace volatile organic compounds of fresh algae and seagrass from the Adriatic Sea (single point...
Performed phytochemical study contributes to the knowledge of volatile organic compounds (VOCs) of Halopteris filicina (Grateloup) Kützing, Dictyota dichotoma (Hudson) J. V. Lamouroux, Posidonia oceanica (L.) Delile and Flabellia petiolata (Turra) Nizamuddin from the Adriatic Sea (single point collection). VOCs were investigated by headspace solid-phase microextraction (HS-SPME) and analysed by gas chromatography and mass spectrometry (GC-MS/FID). H. filicina headspace contained dimethyl sulfide (DMS; 12.8%), C8-compounds (e.g. fucoserratene (I; 9.5%)), benzaldehyde (II; 8.7%), alkane C17, dictyopterene D and C (III, IV), tribromomethane (V), 1-iodopentane, others. F. petiolata headspace was characterized by DMS (22.2%), 6-methylhept-5-en-2-one (9.5%), C17 (9.1%), II (6.5%), compounds I-V. DMS (59.3%), C15 (14.5%), C17 (7.2%) and C19 (6.3%) dominated in P. oceanica headspace. Sesquiterpenes were found in D. dichotoma, predominantly germacrene D (28.3%) followed by other cadinenyl (abundant), muurolenyl
Search Results
7 matching references were found. Bortolomeazzi, R.; Berno, P.; Pizzale, L.; Conte, L.S., Sesquiterpene, alkene, and alkane hydrocarbons in virgin olive oils of different varieties and geographical origins, J. Agric. Food Chem., 2001, 49, 7, 3278-3283, https://doi.org/10.1021/jf001271w . [all data] da Porto, C.; Pizzale, L.; Bravin, M.; Conte, L.S., Analyses of orange spirit flavour by direct-injection gas chromatography-mass spectrometry and headspace solid-phase microextraction/GC-MC, Flavour Fragr. J., 2003, 18, 1, 66-72, https://doi.org/10.1002/ffj.1164 . [all data] Vichi, S.; Pizzale, L.; Conte, L.S.; Buxaderas, S.; López-Tamames, E., Solid-phase microextraction in the analysis of virgin olive oil volatile fraction: characterization of virgin olive oils from two distinct geographical areas of Northern Italy, J. Agric. Food Chem., 2003, 51, 22, 6572-6577, https://doi.org/10.1021/jf030269c . [all data] Vichi, S.; Pizzale, L.; Conte, L.S.; Buxaderas, S.; López-Tamames, E., Solid-phase ...
Comparative study of aroma profile and phenolic content of Montepulciano monovarietal red wines from the Marches and Abruzzo...
Montepulciano is one of the most famous and important red-berried grapes of Italy. This article presents and discusses a comparative study of aroma profile and phenolic content of the Montepulciano wine from the Marches and the Abruzzo regions. The volatile composition of wines was determined by using head- space solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The PDMS fibre was chosen. The dominating esters in Montepulciano wines were ethyl hexa- noate, ethyl decanoate, and ethyl octanoate, whereas phenyl ethanol and 3-methyl-1-butanol were dom- inating alcohols. Phenolic compounds, namely gallic acid, p-coumaric acid, trans-ferulic acid, caffeic acid, trans-resvera- trol, (+)-catechin and ( )-epicatechin, were examined using HPLC-MS with direct injection of wine sam- ples. The total phenolic content of the analysed wines was in the range of 30.4-61.9 mg l 1. The presence of high amounts of esters seems to characterise the volatiles of ...
GERSTEL, Inc. USA
The analysis of volatiles in solids is a common analytical problem. Examples include volatile aroma compounds in foods and plant materials (coffee, tea, and herbs), residual fragrances from soaps and fabric softeners on textiles, and volatiles in polymer resins, films and plastic products. Several techniques are available that allow direct analysis of the volatiles in a variety of solid matrices with little or no sample preparation. Static headspace GC (HS-GC) is probably the most commonly applied technique for analysis of volatiles in solids. Direct thermal desorption (TDS), sometimes referred to as dynamic headspace analysis, and Solid Phase Microextraction (SPME) are alternative techniques that can now be automated. The relative sensitivity of these techniques, and the strengths and limitations of each when applied to a variety of solid matrices should be considered when choosing the most appropriate approach for a new analysis. Until now a direct comparison of these techniques for a variety ...
GERSTEL, Inc. USA
The analysis of flavor compounds in dairy products such as milk, cream, yogurt and cheese as well as their blends with several ingredients usually requires cumbersome sample preparation steps such as liquid/liquid extraction, solid phase extraction or distillation techniques, often with the drawback of organic solvent use. Headspace and purge & trap methods do not use organic solvents, but their analyte range is restricted to volatile compounds and therefore characterize compounds that contribute to the aroma/smell of a sample, not flavor/taste. In addition heating of the sample should be avoided since this would lead to reaction products which dramatically modify the flavor and taste of any dairy product. The sensitivity of solid phase microextraction (SPME) is limited by the small amount of sorptive material that can be coated on the fibers. A new extraction technique, Stir Bar Sorptive Extraction (SBSE), that overcomes the major problems with classical extraction techniques is applied in this ...
Analysis of flavor volatiles of some Iranian rice cultivars by SPME-GC-MS
A combined gas chromatography-mass spectrometry (GC-MS) with headspace solid-phase microextraction (HS-SPME) method has been employed for the analysis of the flavor volatiles of some Iranian rice cultivars (Domsiah, Deylamani, Hashemi, Shirodi and Tarom). The samples were grown in different cities of Mazandaran province. The sampling procedure and chromatographic conditions were same for all samples. The separated chemicals were tentatively identified from their corresponding mass spectra (NIST mass libraries). A total of 49, 31, 29, 16 and 24 peaks were identified and assigned to Domsiah, Deylamani, Hashemi, Shirodi and Tarom rice samples, respectively. The volatile components identified in the five rice cultivars belong to the chemical classes of aldehydes, ketones, alcohols and heterocyclic compounds, as well as fatty acids and esters, phenolic compounds, hydrocarbons, etc. The main identified chemicals in these samples were not identical while some minor chemicals were same, which indicate the
Patent US20030021733 - Porous protective solid phase micro-extractor sheath - Google Patents
A porous protective sheath for active extraction media used in solid phase microextraction (SPME). The sheath permits exposure of the media to the environment without the necessity of extending a fragile coated fiber from a protective tube or needle. Subsequently, the sheath can pierce and seal with GC-MS septums, allowing direct injection of samples into inlet ports of analytical equipment. Use of the porous protective sheath, within which the active extraction media is contained, mitigates the problems of: 1) fiber breakage while the fiber is extended during sampling, 2) active media coating loss caused by physical contact of the bare fiber with the sampling environment; and 3) coating slough-off during fiber extension and retraction operations caused by rubbing action between the fiber and protective needle or tube.
Search Results
You may also wish to search for items by Conte. 14 matching references were found. Gambaretto, G.; Scipioni, A.; Conte, L., Determination of the heats of formation and nitration of 3-nitro-4-chlorobenzotrifluoride and 3,5-dinitro-4-chlorobenzotrifluoride, Atti - Ist. Veneto Sci., Lett. Arti, Cl. Sci. Fis., Mat. Nat., 1980, 138, 189-194. [all data] Alessi, P.; Cortesi, A.; Napoli, M.; Conte, L., Activity coefficients at infinite dilution of organic solvents in hydrofluoroparaffins, J. Fluorine Chem., 1995, 72, 43-7. [all data] Gambaretto, G.P.; Conte, L.; Napoli, M.; Legnaro, E.; Carlini, F.M., Determination of the solubility of fluorine in various solvents, J. Fluorine Chem., 1993, 60, 19-25. [all data] Koprivnjak, O.; Conte, L.; Totis, N., Influence of olive fruit storage in bags on oil quality and composition of volatile compounds, Food Technol. Biotechnol., 2002, 40, 2, 129-134. [all data] Piasenzotto, L.; Gracco, L.; Conte, L., Solid phase microextraction (SPME) applied to honey quality ...
Foods | Free Full-Text | Volatile Composition of Smoked and Non-Smoked Iranian Rice
In this work, the volatile profiles of smoked and non-smoked Iranian rice were identified, and their relative abundance was calculated and compared. Headspace solid-phase microextraction together with gas chromatography-mass spectrometry (SPME-GC-MS) were used to extract and identify the volatile compounds. The main groups of volatiles in Iranian rice were aldehydes, ketones, phenol derivatives, furans, linear hydrocarbons, esters and terpenes. The chemical family aldehydes was the most abundant one in the profile of non-smoked rice, while phenol derivatives and furans predominated in smoked samples. This study is the first one reporting comparative data of volatile compounds between smoked and non-smoked Iranian rice.
Subject: ionic strength / Journal: Journal of chromatography / Publication Year: 2019 / Subject: gas chromatography-mass...
In this study, three kinds of Zeolite imidazolate framework-8 (ZIF-8), synthesized by solvothermal, stirring and ball-milling method, were fabricated on the stainless steel wire via sol-gel technique. These fibers were used as solid phase microextraction (SPME) coating materials and applied for analyzing 16 polycyclic aromatic hydrocarbons (PAHs) and 11 nitro polycyclic aromatic hydrocarbons (NPAH ...
Development of a PID based on-line tar measurement method : Proof of concept
Gasification of biomass will likely play an important role in the production of energy and chemicals in a future sustainable society. However, during gasification impurities, such as tars, will be formed. Tars may cause fouling and blockages of equipment downstream the gasifier. It is therefore important to minimize the formation of tars, alternatively to remove the formed tars. These processes need to be monitored, which makes it necessary to develop tar analysis methods suitable for this task.. This work describes the development of two tar analysis methods, an on-line method based on a photoionization detector (PID) and an off-line method based on solid phase microextraction (SPME). Both methods were successfully validated against the established solid phase adsorption (SPA) method.. The method based on PID was shown to have a very fast response time. Furthermore, the PID method is selective towards tar, but only limited information will be obtained regarding the composition of the tar ...
Most recent papers with the keyword critical illness | Read by QxMD
Meropenem is a widely used antimicrobial for the treatment of infections associated with the use of invasive medical devices in intensive care unit patients. These treatments are not always effective, in fact, in-vitro studies have demonstrated the difficulty of antimicrobials to penetrate into the biofilm, however in-vivo studies of the effect of these compounds is a trend, mostly because of the complexity of pulmonary samples extracted from ETTs. Therefore, the objective of this study was to evaluate in-tube solid phase microextraction (in-tube SPME) coupled to capillary liquid chromatography (CapLC) with DAD to determine meropenem in ETTs in order to estimate the penetration capability into the biofilm ...
Fast and sensitive environmental analysis utilizing microextraction in packed syringe online with gas chromatography-mass...
A new sensitive, selective, fast and accurate technique for online sample preparation was developed. Microextraction in a packed syringe (MEPS) is a new miniaturised, solid-phase extraction (SPE) technique that can be connected online to GC or LC without any modifications. In MEPS approximately 1 mg of the solid packing material is inserted into a syringe (100-250 ml) as a plug. Sample preparation takes place on the packed bed. The bed can be coated to provide selective and suitable sampling conditions. The new method is very promising. It is very easy to use, fully automated, of low cost and rapid in comparison with previously used methods. The determination of polycyclic hydrocarbons (PAHs) in water was performed using MEPS as sample preparation method online with gas chromatography and mass spectrometry (MEPS-GC-MS). The results from MEPS as sample preparation were compared with other techniques such as stir bar sorptive extraction (SBSE) and solid-phase microextraction (SPME). The method was ...
Repositorio da Producao Cientifica e Intelectual da Unicamp: Odor Significance Of The Volatiles Formed During Deep-frying With...
Palm olein is currently considered to be one of the best options for deep-frying, but as with any other edible oil, during frying, deteriorative reactions produce off-flavor compounds that reduce the oil sensory quality. This study assessed the odor significance of the volatiles formed during 136 h of deep-frying a chicken product in palm olein, aiming to identify potential markers of the oil sensory quality during frying. The volatiles were isolated by solid phase microextraction, and identified by GC-MS. Trained judges assessed the odor intensity and quality of the volatiles formed during frying, evaluating the GC effluents through a GC-olfactometry technique called OSME. Two hundred and eight volatiles were detected by GC/MS in the palm olein after 136 h frying. Of these, heptanal, t-2-heptenal, decanal and t-2-undecenal were identified as potential markers of the sensory quality of palm olein during frying. Hexanal, pentanal and pentane, usually associated with lipid oxidation, showed no ...
Torion portable GC-MS | Norlab
Volatile organic compounds were rapidly sampled and concentrated from water in 5 seconds using a CUSTODION solid phase microextraction syringe. Compounds were analyzed on-site using the TRIDION portable gas chromatograph-toroidal ion trap mass spectrometer. ...
OPUS 4 | Human blood and plasma partition coefficients for C4-C8 n-alkanes, isoalkanes, and 1-alkenes
Adult; Air; Alkanes; Alkenes; Female; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Solid Phase Microextraction ...
OPUS 4 | Human blood and plasma partition coefficients for C4-C8 n-alkanes, isoalkanes, and 1-alkenes
Adult; Air; Alkanes; Alkenes; Female; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Solid Phase Microextraction ...
Comparison of Edible Oils by GCxGC-TOF-MS and GC-High Resolution TOF-MS for Determination of Food Fraud: A Foodomics Approach...
Here, a method to characterize edible oils and edible oil mixtures through fingerprinting and the isolation of individual analyte differences is reported. Aroma and flavor analytes in extra virgin olive, olive, peanut, grapeseed, and vegetable oils were sampled with headspace solid-phase microextraction (HS-SPME).
Chemistry Student Honors Theses | Chemistry | University of Redlands
Solid Phase Microextraction with Polystyrene-Poly(dimethylsiloxane) block copolymers, Andrew Schlaus and Rebecca Lyons, Advisor. ...
Ultra trace analysis of PAHs by designing simple injection of large amounts of analytes through the sample reconcentration on...
A simple solventless injection method was introduced based on the using of a solid-phase microextraction (SPME) fiber for injection of large amounts of the analytes extracted by the magnetic solid phase extraction (MSPE) procedure. The resulted extract from MSPE procedure was loaded on a G-coated SPME fiber, and then the fiber was injected into the gas chromatography (GC) injection port. This method combines the advantages of exhaustive extraction property of MSPE and the solvent-less injection of SPME to improve the sensitivity of the analysis. In addition, the analytes were re-concentrated prior to inject into the gas chromatography (GC) inlet because of the organic solvent removing from the remaining extract of MSPE technique. Injection of the large amounts of analytes was made possible by using the introduced procedure. Fourteen polycyclic aromatic hydrocarbons (PAHs) with different volatility were used as model compounds to investigate the method performance for volatile and semi-volatile ...
Determination of Trace Leaching Phthalate Esters in Water and Urine from Plastic Containers by Solid-Phase Microextraction and...
DSpace-CRIS consists of a data model describing objects of interest to Research and Development and a set of tools to manage the data. Standard DSpace is used to deal with publications and data sets, whereas DSpace-CRIS involves other CRIS entities: Researcher Pages, Projects, Organization Units and Second Level Dynamic Objects (single entities specialized by a profile, such as Journal, Prize, Event etc; because any profile can define its own set of properties and nested objects ...
Extraction and Determination of Three Chlorophenols by Hollow Fiber Liquid Phase Microextraction - Spectrophotometric Analysis,...
A method termed hollow fiber liquid phase microextraction (HF-LPME) was utilized to extract three chlo- rophenols, 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6- trichlorophenol (2,4,6-TCP), separately from water. The extracted chlorophenols were then separated, identified, and quantified by UV-Vis spectrophotometry with photodiode array detection (UV-Vis/DAD). In the study, experimental con-ditions such as organic phase identity, acceptor phase volume, sample agitation, extraction time, acceptor phase NaOH concentration, donor phase HCl concentration, salt addition, and UV absorption wavelength were optimized. The statistical parameters of the proposed method were investigated under the selected con-ditions. The analytical characteristics of the method such as detection limit, accuracy, precision, relative standard deviation (R.S.D.) and relative standard error (R.S.E.) was calculated. The results showed that the proposed method is simple, rapid, accurate and precise for the analysis of
Solid Phase Microextraction of Volatile Emissions of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): Influence of Fly...
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
Simultaneous analysis of 10 trihalomethanes at nanogram per liter levels in water using solid-phase microextraction and gas...
Trihalomethanes are predominantly formed during disinfection of water via reactions of the oxidant with natural organic matter. Even though chlorinated and brominated trihalomethanes are the most widespread organic contaminants in drinking water, when iodide is present in raw water iodinated trihalomethanes can also be formed. The formation of iodinated trihalomethanes can lead to taste and odor problems and is a potential health concern since they have been reported to be more toxic than their brominated or chlorinated analogs. Currently, there is no published standard analytical method for I-THMs in water. The analysis of 10 trihalomethanes in water samples in a single run is challenging because the iodinated trihalomethanes are found at very low concentrations (ng/L range), while the regulated chlorinated and brominated trihalomethanes are present at much higher concentrations (above μg/L). An automated headspace solid-phase microextraction technique, with a programmed temperature vaporizer ...
Effect of high hydrostatic pressure and temperature on volatile off-flavors formation in milk
The aroma of milk has been often defined as bland and pleasant, yet characteristic. Conventional thermal processing of milk can certainly extend shelf life, but inevitably changes its flavor. High pressure processing has been suggested as an alternative for milk pasteurization with improved fresh flavor retention. The objective of this project was to study off-flavor volatile formation in milk subjected to high hydrostatic pressure combined with moderate heating. Two sensitive and accurate new techniques were developed for the analysis of off-flavor compounds. Solid-phase microextraction/gas chromatography with flame ionization detection was used for the analysis of aldehydes, ketones, and dimethyl sulfide. Solid-phase microextraction/gas chromatography with pulsed flame photometric detection was used for the selective analysis of trace sulfur compounds. Milk subjected to different treatment combinations of pressure, temperature and time showed that aldehydes formation is promoted during high ...
CICECO Determination of 5-hydroxymethylfurfural in honey, using headspace-solid-phase microextraction coupled with a...
High concentrations of 5-hydroxymethylfurfural (HMF) in honey provide an indication of overheating under inappropriate storage conditions or aging. Conventional methods for determining HMF are cumbersome and require expensive equipment or hazardous reagents. Hence the aim of this study was to propose a new analytical tool for HMF determination in honey, using a low cost acoustic wave sensor. Volatile organic compounds (VOCs) of honey samples were extracted, using the solid phase microextraction (SPME) technique, and HMF was quantified, using a piezoelectric quartz crystal with gold electrodes coated with a layer of decamolybdodivanado phosphoric acid, sensitive to HMF. The reliability of the proposed method was confirmed after comparing the results of HMF quantification with those obtained by the conventional spectrophotometric White method, and no statistical differences were found (alpha = 0.05). (C) 2016 Elsevier Ltd. All rights reserved.
Release of sex pheromone and its precursors in the pine sawfly Diprion pini (Hym., Diprionidae)
The first identification of a sex pheromone of a pine sawfly (Hymenoptera, Diprionidae) dates back almost thirty years. Since then, female-produced pheromones of over twenty diprionid species have been investigated by solvent extraction followed by separation and identification. However, no study has shown what the females actually release. Collection of airborne compounds using absorbtion on charcoal filter as well as solid phase microextraction (SPME) followed by analysis employing gas chromatography combined with mass spectrometry (GC-MS), revealed an unusual system in Diprion pini, in which the pheromone precursor alcohol, 3,7-dimethyl-2-tridecanol, is released together with acetic, propionic, butyric and isobutyric acids. The corresponding acetate, propionate and butyrate esters of 3,7-dimethyl-2-tridecanol were also found in the samples. All esters were electrophysiologically active, and the propionate and isobutyrate were attractive in trapping experiments. Based on these and earlier ...
Direct link
Pine weevils cause major damage to newly planted conifer seedlings in reforestation areas. However, recent findings indicate that small (mini) seedlings, planted at the age of 7-10 weeks, are gnawed less by pine weevils than the larger, conventionally planted seedlings. Thus, it has been proposed that planting young conifer seedlings in clear-cut areas may reduce the damage caused by pine weevils. In attempts to determine why mini seedlings appear to be less damaged by pine weevils than conventional seedlings, the volatiles released by Norway spruce and Scots pine mini seedlings were investigated, since such chemicals are of great importance in herbivore-plant communication, inter alia acting as repellents, attractants or antifeedants.. Volatiles from the seedlings were collected, separated and identified by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry.. The results show that there are high levels of chemodiversity among both spruce and pine seedlings. ...
MBAA TQ 2002 - Use of the Electronic Nose and Gas Chromatography-Mass Spectrometry to Determine the Optimum Time for Aging of...
The purpose of this study was to determine the influence of aging time on the development of the aroma characteristics of beer. Volatiles produced from Sleeman Cream Ale during aging for up to 28 days at -1 C were sampled periodically and monitored by a trained sensory panel, by headspace analysis with an electronic nose (EN), and by solid phase microextraction coupled with gas chromatography-mass spectrometry. All three types of analyses discriminated between groups of samples taken early, in the middle, and at the end of the aging periods and separated aged beer into two or three distinct clusters. Intertrial differences were observed and were attributed to production variations. The balance of sweet and bitter notes was optimum at 14 and 21 days of aging. In addition, the EN was able to distinguish finished beer made after different periods of aging, while the sensory panel was not. The results suggest that the EN can complement traditional chemical and sensory approaches to the optimization of beer
Vliv aromaticky aktivních látek na chutnost jogurtů | BUT Digital library
This diploma thesis deals with the questions of determination of aroma active compounds present in yoghurts. These compounds are crucial for flavour of these fermented dairy products. Four types of yoghurts were analyzed, creamy (10 % of fat), medium-fat and medium-fat Bio (3 % of fat) and light (0,1 % of fat), produced by Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Five groups of different aroma active compounds such as ketones, aldehydes, organic acids and their esters and alcohols in different amounts were determined. These compounds are mostly metabolic products of Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, dairy yoghurt cultures usually used for yoghurt production. Less amounts are present in cows milk or in dairy additives. Yoghurts were simultaneously sensorially evaluated using ranking test and scale test for determination ...
Biology-Online • View topic - The Fiber Disease
A solid-phase microextraction (SPME) procedure has been developed for the determination of 16 US Environmental Protection Agency promulgated polycyclic aromatic hydrocarbons (PAHs). Five kinds of SPME fibers were used and compared in this study. The extracted sample was analyzed by gas chromatography with flame ionization detection or mass spectrometry. Parameters affecting the sorption of analyte into the fibers, including sampling time, thickness of the fiber coating, and the effect of temperature, have been examined. Moreover, the feasibility of headspace SPME with different working temperatures was evaluated. The method was also applied to real samples. The 85-microm polyacrylate (PA) and 100-microm poly(dimethylsiloxane) (PDMS) fibers were shown to have the highest affinities for the selected PAHs. The PA fiber was more suitable than the PDMS fiber for the determination of low-ring PAHs while high sensitivity of high-ring PAHs was observed when a 100-microm PDMS fiber was used. The method ...
Improving the knowledge on Piper betle: targeted metabolite analysis and effect on acetylcholinesterase. - Semantic Scholar
Piper betle is a species growing in South East Asia, where its leaves are economically and medicinally important. To screen the highest possible number of volatile and semivolatile components, the leaves were subjected to headspace solid-phase microextraction, hydrodistillation and Soxhlet extraction, prior to analysis by GC/MS. Fifty compounds (identified by comparison with standard compounds or tentatively by National Institute of Standards and Technology database) were determined, 23 being described for the first time in this matrix. An aqueous extract was also analysed, in which only seven compounds were characterized. The organic acids composition of this extract was determined by HPLC/UV and eight compounds are reported for the first time in P. betle. This extract also displayed acetylcholinesterase inhibitory capacity.
The Best Dry Dog Food for Your Pit Bull | Pitbulls.org
In a previous article, we discussed how to choose a quality commercial dog food for your pit bull. Today, well give you our recommendations for the best dry dog foods, including detailed reviews describing why we made the selection.
Dry Dog Food Evaluation Criteria
In order to be selected for our list of the best kibbles for your pit bull, dry dog foods must meet the following criteria:
The Best Dry Dog Food for Your Pit Bull | Pitbulls.org
In a previous article, we discussed how to choose a quality commercial dog food for your pit bull. Today, well give you our recommendations for the best dry dog foods, including detailed reviews describing why we made the selection.
Dry Dog Food Evaluation Criteria
In order to be selected for our list of the best kibbles for your pit bull, dry dog foods must meet the following criteria:
900+ Dry Dog Food ideas | dry dog food, dog food recipes, food
Mar 7, 2018 - Explore Dog Stuffs board Dry Dog Food on Pinterest. See more ideas about dry dog food, dog food recipes, food.
Cellulose Fibre Coatings | Architecture & Design
See the latest products, news and videos from suppliers of Cellulose Fibre Coatings. Architecture & Design showcases new building and architectural products to architects, designers, specifiers, engineers and builders. For more than 50 years, Architecture & Design has been the leading hub for the professionals creating Australias buildings.
Coupling Desorption Electrospray Ionization with Solid-Phase Microextraction for Screening and Quantitative Analysis of Drugs...
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
PEDIGREE Adult Dry Dog Food
The best dry dog food can offer mouthwatering flavors and immune system to your dogs, meanwhile, it helps keep the skin and coat healthy and shiny. If you keep a dog, coming here … [Read more...] about 5 Best Dry Dog Foods - Providing Mouthwatering Flavors & Immune System ...
Best Dry Dog Food: The 10 Best Brands in the Market Today
The best dry dog food possible to feed them. In these cases, you have to find the best dry dog food for you and your dogs needs.
Natural dry dog food pet food dog feed, View Natural dry dog food pet food dog feed , AIBEI Product Details from Shanghai Fubei...
Natural dry dog food pet food dog feed,, Pet Food, Dogs, Eco-Friendly, Stocked.Source from Shanghai Fubei Pet Food Co., Ltd. on Alibaba.com.
Life Advantage Diet Dry Dog Food, View Life Advantage Diet Dry Dog Food, BILE Product Details from Shanghai Fubei Pet Food Co.,...
Life Advantage Diet Dry Dog Food,, Pet Food, Dogs, Eco-Friendly, Stocked.Source from Shanghai Fubei Pet Food Co., Ltd. on Alibaba.com.
Wysong Adult Dry Dog Food | Adult Dog Dry Food - 1800PetMeds
Wysong Adult Dry Dog Food is a pet food for adult dogs. Wysong Adult Dry Dog Food contains only fresh, whole ingredients and doesnt contain anything artificial or non-nutritional for your adult dog.
Dry dog food pellet extrusion make machinery
Dog Treat/Chewing Food Machine offers AH(X)30 series: a Dry dog food pellet extrusion make machinery Massalfa Microwave selection of Genuine Dog Treat/Chewing Food Machine at Wholesale Prices. We are a Dry dog food pellet extrusion make machinery Certified Parts Retailer
James Wellbeloved Senior Dry Dog Food - Fish and Rice - 7.5kg | Free UK Delivery
James Wellbeloved Senior Dry Dog Food carefully crafted and nutritionally balanced complete dry dog food for the health and wellbeing of senior dogs from 7...
despacia: Review Royal Canin Dry Dog Food, Shih Tzu 24 Formula, 2.5-Pound Bag
In general as far as I know customers who bought Royal Canin Dry Dog Food, Shih Tzu 24 Formula, 2.5-Pound Bag or other products in the Internet also were interested in reviews, cheap & lowest prices in outlets and stores, shipping, gift ideas, city deals, sales, coupons online, new, holiday & daily deals, bargain, best buy products including special offers on Royal Canin Dry Dog Food, Shih Tzu 24 Formula, 2.5-Pound Bag, best deals, discount coupons, top & hot deals, great offers, last minute deals and so on ...
Freely Beneficial Broth Gut Health Blend Dry Dog Food Topper, 12-oz bottle - Yahoo Shopping
Freely Beneficial Broth Gut Health Blend Dry Dog Food Topper, 12-oz bottle; Get your pal psyched about dinner while taking care of his tummy with Freely Beneficial Broth Gut Health Blend Dry Dog Food Topper. This bison bone broth topper can be used as...
Top 10 Dry Dog Food Made In Usa - Home Previews
Best dry dog food made in usa Reviews :If you are reading this, then you already know about dry dog food made in usa is a great product for you, your
Buy Pure Vita Duck & Oatmeal Dry Dog Food - Free Shipping
Buy Pure Vita Duck & Oatmeal Dry Dog Food & Other Great Pure Vita Dry Dog Food Formulas at K9Cuisine.com - Great Customer Service & Fast Free Shipping.
Compare Lifes Abundance Dog Food to Halo Spots Stew Wholesome Chicken Adult Dry Dog Food
This dog food comparison (dog food rating) is a review of Lifes Abundance premium natural dog food versus Halo Spots Stew Wholesome Chicken Adult Dry Dog Food. Lifes Abundance is a healthy dog food.
Polymer-coated hollow-fiber microextraction of estrogens in water samples with analysis by gas chromatography-mass spectrometry...
A novel sorbent, dihydroxylated polymethylmethacrylate (DHPMM), coated on hollow-fiber membrane, is used for the polymer-coated hollow-fiber microextraction of trace amounts of natural and synthetic estrogens, such as diethylstilbestrol, estrone, 17β-estradiol and 17α-ethynylestradiol, in aqueous samples. In this procedure, estrogens were extracted using the functionalized polar DHPMM polymer with derivatization using N-methyl-N-(trimethylsilyl)trifluoroacetamide followed by gas chromatography-mass spectrometric analysis. The detection limits for estrogens in aqueous sample were between 0.03 and 0.8 ng l-1 and the calibration curves were linear over the concentration range 0.05-10 μg l -1 and had correlation coefficients of ,0.994. The relative standard deviations (RSDs) ...
Academic Journals
Authors: EVA MARGUI, MANUELA HIDALGO Abstract: Liquid phase microextraction (LPME) procedures have been widely used in combination with atomic and emission spectroscopic techniques for the isolation and preconcentration of trace elements. However, its application in combination with total reflection X-ray spectrometry (TXRF) is still scarce. In this paper, we evaluate the possibilities and drawbacks of a two-phase hollow fiber LPME procedure in combination with TXRF for the simultaneous determination of trace amounts of Cr, Ni, Cu, Zn, Pb, and Cd in aqueous samples. After extraction of the analytes by using the optimum conditions (sample volume: 25 mL, complexing agent: APDC, organic solvent: hexylbenzene, extraction time: 2 h, extraction speed: 660 rpm), 10 $\mu $L of the preconcentrated sample was deposited on a preheated quartz reflector, dried on a hot plate at 80 $^{\circ}$C, and analyzed by TXRF. Using such conditions, limits of detection lower than 3 $\mu $g L$^{-1}$ were obtained for all ...
Toxins | Free Full-Text | Determination of Ochratoxin A in Wheat and Maize by Solid Bar Microextraction with Liquid...
Solid bar microextraction (SBME), followed by liquid chromatography with fluorescence detection (HPLC-FLD), for the quantification of ochratoxin A in wheat and maize was developed. Ground wheat and maize grains were extracted with acetonitrile-water-acetic acid (79:20:1, v/v/v), followed by defatting with cyclohexane, and subjected to SBME-LC-FLD analysis. SBME devices were constructed by packing 2 mg sorbent (C18) into porous polypropylene micro-tubes (2.5 cm length, 600 μm i.d., and 0.2 μm pore size). SBME devices were conditioned with methanol and placed into 5 mL stirred sample solutions for 70 min. After extraction, OTA was desorbed into 200 μL of methanol for 15 min, the solution was removed in vacuum, the residue was dissolved in 50 μL of methanol-water (1:1, v/v) and ochratoxin A content was determined by HPLC-FLD. Under optimized extraction conditions, the limit of detection of 0.9 μg·kg−1 and 2.5 μg·kg−1 and the precision of 3.4% and 5.0% over a concentration range of 1 to 100
中国科学院大连化学物理研究所机构知识库(DICP OpenIR): Acetone-activated polyimide electrospun nanofiber membrane forthin-film microextraction and...
李盛红,吴大朋,闫晓辉,&关亚风.(2015).Acetone-activated polyimide electrospun nanofiber membrane forthin-film microextraction and thermal desorption-gas chromatography-mass spectrometric analysis of phenols in environmental water.JOURNAL OF CHROMATOGRAPHY A,1411(0),1 ...
Transport of chlorpromazine in the Caco-2 cell permeability assay: a kinetic study
The intestinal transport of compounds can be measured in vitro with Caco-2 cell monolayers. We took a closer look at the exposure and fate of a chemical in the Caco-2 cell assay, including the effect of protein binding. Transport of chlorpromazine (CPZ) was measured in the absorptive and secretory direction, ... read more with and without albumin basolaterally. Samples were taken from medium, cells, and well plastic. For the secretory transport experiments with albumin, the free CPZ concentration at the start of the experiment was measured by negligible depletion-solid phase microextraction (nd-SPME). Recovery of CPZ from the medium was low, especially in the absorptive transport direction. CPZ was found in the cells (≤20%) and bound to the well plastic (≤25%), and 94% of CPZ was bound to albumin. An initial lag phase was observed, which was likely caused by partitioning of CPZ between the donor concentration and the Caco-2 cells; after 20 min, transport of CPZ to the receiver compartment ...
Bil Jac Large Breed Select Dry Dog Food - Review & Analysis
Your dog will love the flavor of the Bil-Jac Super Premium Dog Food, and manufacturers are sure that you will love the beneficial effects that this formula will have on your furry friend. Pet owners quickly notice a brighter, fuller and better-looking coat on their pet. Your dogs fur coat will look better because he is receiving a healthy bowl of nutrition every morning, hell have softer skin, brighter eyes, increased activity, improved muscle tone and, believe it or not, a smaller & firmer stool-a sign that hes getting all the vital nutrients he needs.. Bill Jacs dog food is unique in its approach to your pets protein needs. Since your dog is a carnivore and loves to eat protein packed foods, Bil-Jac provides a great variety of fresh chicken protein in his diet that cant be found in any other dry dog food available. The manufacturers begin by using high quality and high quantity of fresh chicken and fresh chicken organ meat, which is sourced fresh from nearby chicken processors. From ...
The 10 Best Large Breed Dry Dog Food Brands For 2020 - Dog Food Network
Finding the best large breed dry dog food is one of the most important decisions you can make as a dog owner. Compared to their smaller counterparts, large breed dogs require a specifically formulated dog food based on breed, size, age and any health related issues they have
Whole Earth Farms Grain Free Recipe with Turkey and Duck Dry Dog Food - Alpha-Dog Pet Center - Amherst, OH
Whole Earth Farms Grain Free dry dog food recipes provide natural, grain free dog foods with real meat, poultry or fish that support the nutrition needs of your dog. Whole Earth Farms is a wholesome line of naturally nutritious dog food and cat food that offers all the goodness from the earth at a great value. Our Whol
Pedigree Puppy Growth & Protection Chicken & Vegetable Flavor Dry Dog Food, 3.5 lb
Pedigree Puppy Growth & Protection Chicken & Vegetable Flavor Dry Dog Food, 3.5 lb |p|PEDIGREE Puppy Growth and Protection Chicken & Vegetable Flavor Dog Food is formulated to help your pup keep up with the big dogs. This puppy formula is made with DH
how much water to add to dry dog food
mouth of your dog. I think i am wrong but now i decide i will follow your all steps and suggestions. To quantify the difference, normal wet canned food is typically 85% moisture. From what Ive seen it is really important for a dog to have water, and if a dog doesnt drink much that is a reason to add water to their food. Add some spoons of water initially to the dry food to soften it. What Are The Benefits of Adding Water to Dry Dog Food? Feed a good quality food, and make any changes between brands gradually, to allow your dog to get used to the taste and texture of the new food. For instance, your dog can develop a case of periodontal disease, which is very serious because it will end up destroying the gums and tissue that supports its teeth. However, you The percentage of dry matter of the product is equal to 100% minus the percentage of moisture guaranteed on the label. Keep increasing it eat to test the tolerance levels of your pet. Cheap ingredients are used to make dog food more ...
Purina Pro Plan Adult Large Breed Formula Dry Dog Food - PetSaver Healthy Pet Superstore
Offer your dog a meal thats delicious and nourishing when you serve him Purina Pro Plan Brand Dog Food Large Breed Chicken & Rice Formula adult dry dog food. The high level of protein, along with proper exercise, helps to promote muscle conditioning, while natural prebiotic fiber nourishes specific intestinal bact
Purina Recalls One Batch of Dry Dog Food Due to Possible Salmonella | PetCareRx
Alternatives:. If your dog eats another type of food in addition to one mentioned above, feed your pet the other food only. If you need to switch your pet to a new food, consider one of these options.. Wellness Super5Mix Just for PuppyCanidae All Life Stages Formula Dry Dog Food. Since switching a dogs food quickly (instead of mixing foods over a period of a few days) can cause stomach distress, talk to your vet if your pet experiences digestive issues.Read the full announcement. from the FDA.. Dont miss any recalls: Subscribe to The Wet Nose Press. and keep your pets protected by staying in the know!. ...
Supreme Source Adult Dry Dog Food Grain Free Salmon Meal & Sweet Potato Recipe - 11 Lb - Safeway
Shop Supreme Source Adult Dry Dog Food Grain Free Salmon Meal & Sweet Potato Recipe - 11 Lb from Safeway. Browse our wide selection of Dog Food - Dry for Delivery or Drive Up & Go to pick up at the store!
Nutro Max Dry Dog Food | Dog Owner Ratings | Right...
5.0/5 - 1 reviews Dog vets and owners rate the effectiveness of Nutro Max Dry Dog Food for Dog Adult Dog Foods. Is this a treatment you can do yourself, or do you need to see a vet? Add your review.
Royal Canin Large Breed Digestive Care Dry Dog Food
- Pet Discounters
When it comes to your dogs sensitive stomach, how do you know which dog food is best? Royal Canin knows theres an exact science to your dogs digestive health, starting with precise nutrition so they can be their most magnificent self. Royal Canin Large Digestive Care dry dog food (formerly Maxi Digestive Care) is ta
Hills Prescription Diet w/d Multi-Benefit Digestive, Weight, Glucose, Urinary Management Chicken Flavor Dry Dog Food, 8.5-lb...
Buy Hills Prescription Diet w/d Multi-Benefit Digestive, Weight, Glucose, Urinary Management Chicken Flavor Dry Dog Food, 8.5-lb bag at Chewy.com. FREE shipping and the BEST customer service!
Hills Prescription Diet i/d Digestive Care Low Fat Chicken Flavor Dry Dog Food, 17.6-lb bag - Chewy.com
Buy Hills Prescription Diet i/d Digestive Care Low Fat Chicken Flavor Dry Dog Food, 17.6-lb bag at Chewy.com. FREE shipping and the BEST customer service!