• Typically, despite being the most popular method used in gas chromatography-mass spectrometry (GC-MS), electron ionization (EI) results in weak or absent molecular ions in the mass spectral data, making it difficult to identify unknowns by EI alone. (jeolusa.com)
  • However, this technology leverages soft ionization data for molecular ion information with the large number of fragment ions observed in EI mass spectra to automatically interpret this data into potential structural formulas, even if the operator has no knowledge of mass spectrometry or AI. (jeolusa.com)
  • Samples were analyzed by gas chromatography with nitrogen-phosphorus detection GC-NPD and electron ionization GC-mass spectrometry MS utilizing selected ion monitoring. (erowid.org)
  • Developments in the application of new ionization and new separation techniques that have become standard analytical mass spectrometric capabilities. (astm.org)
  • Title : Quantitation of trans-fatty acids in human blood via isotope dilution-gas chromatography-negative chemical ionization-mass spectrometry Personal Author(s) : Kuiper, Heather C.;Wei, Na;McGunigale, Samantha L.;Vesper, Hubert W. (cdc.gov)
  • The respective concentrations in the plasma and in the arterial wall were determined by gas chromatography-flame ionization or mass spectrometry. (maastrichtuniversity.nl)
  • Various methods for ionization such as electron ionization, chemical ionization and cold electron ionization are used, depending on the application. (infinitalab.com)
  • The most common and generally considered the workhorse of PCB analysis is gas chromatography-electron capture detection (GC-ECD), the next instrument is gas chromatography (GC) with low resolution, electron ionization mass spectrometry (MS), and in recent years the industry has added the most sensitive instrument thus far for PCB congener analysis ― Gas Chromatography coupled with High Resolution Mass Spectrometry HRGC/HRMS. (pacelabs.com)
  • Quantitative performance of the method was tested with two authentic urine samples, and the results were in good agreement with those obtained with conventional GC-electron ionization-MS after derivatization. (aalto.fi)
  • This method is applicable to the determination of the sum of SCCPs in unfiltered surface water, ground water, drinking water and waste water using gas chromatography-mass spectrometry with electron capture negative ionization (GC-ECNI-MS). (iso.org)
  • Instrumental techniques required to support the vapor program include the PTR-MS systems (available in a mobile configuration for deployment to customer locations), gas chromatography with detectors including mass spectrometry, flame ionization, and electron capture, high performance liquid chromatography, ICP/OES and ICP/MS. The program continues to expand with the addition of capabilities required to support and solve client's needs. (azurewebsites.net)
  • The emphasis is on understanding the fundamental processes involved, the instrumentation used, including different ionization sources and mass analyzers, and interpretation of generated data. (lu.se)
  • Gas chromatography in combination with chemical ionization and electron ionization and liquid chromatography in combination with electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photo ionization will be covered. (lu.se)
  • 2001). Mass spectroscopy (MS) in ion selective mode is used to confirm peak identity of the suspected compounds. (cdc.gov)
  • Technologies used in physical forensics include liquid chromatography-mass spectrometry (LC-MS) for explosives and fiber analysis, gas chromatography-mass spectrometry (GC-MS) for explosives, scanning electron microscopy, capillary electrophoresis (CE), ion mobility spectrometry (IMS), laser-induced breakdown spectroscopy (LIBS) for glass, and advanced computational methods. (worldwidelearn.com)
  • Gas chromatography/mass spectroscopy analysis showed that the extract contained monoterpene hydrocarbons and phenolic compounds, the major ones being carvacrol and thymol and to a lesser extent p-cymene, 1-octacosanol, creosol, and phytol. (hindawi.com)
  • Significant breakthroughs in analytical chemistry encompass advances in spectroscopy techniques (e.g. atomic absorption, mass spectrometry, and Raman spectroscopy), which enhance the sensitivity and selectivity of analytical instruments. (aspenquantum.com)
  • Consequently, visual counting techniques, such as those employed for asbestos fibers, must be used, and a wide variety of these techniques have been used for quantification of microplastics, including Fourier transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy. (haleyaldrich.com)
  • The Board published draft standardized methods for extraction and microplastic analysis in September 2021 and identified Raman spectroscopy and infrared spectroscopy as the proposed analytical methods for testing drinking water for microplastics. (haleyaldrich.com)
  • The Raman spectroscopy method was selected for chemical identification and determination of microplastics greater than 20 µm, while infrared spectrometry was proposed for microplastics greater than 50 µm in size. (haleyaldrich.com)
  • ROS production was assessed by electron-spin resonance spectroscopy in the aorta, endothelial function of aortic rings and atherosclerosis in the aortic sinus was quantitated after 4 weeks. (maastrichtuniversity.nl)
  • Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits and/or to improve accuracy and precision. (cdc.gov)
  • Quantification of the metabolites DMP, DMTP, and DMDTP in urine samples is typically accomplished using gas chromatography (GC) with nitrogen phosphate detection (NPD) or with flame photometric detection (FPD). (cdc.gov)
  • GC with NPD or electron capture detection (ECD) has been used to quantify levels of guthion and other pesticides in human serum and urine (Pitarch et al. (cdc.gov)
  • Serum organochlorine concentrations were measured by high-resolution gas chromatography with electron-capture detection and negative ion chemical ionisation mass spectrometry. (nih.gov)
  • The gas chromatograph mainly consists of 5 major systems: gas circuit system, sample injection system, separation system, temperature control system, and detection and recording system. (antiteck.com)
  • 1) in the first part of the study, the analytical methods examined were isocratic high pressure liquid chromatography (HPLC) with ultraviolet (UV) detection, capillary gas chromatography (GC) with temperature programming and flame ionisation detection and gas chromatography-mass spectrometry (GC-MS). Twelve NSAIDs in common use in the UK were selected as test compounds for the evaluation of the separating ability, selectivity and sensitivity of detection of the three methods. (gla.ac.uk)
  • In addition, fluorescence spectrometry and electrochemical detection (ECD) were examined to assess their value as additional HPLC detection systems which might increase the selectivity or sensitivity of the method. (gla.ac.uk)
  • c) GC-MS : Gas chromatography with mass spectrometric detection was carried out using similar GC conditions to those described above. (gla.ac.uk)
  • To improve the accuracy of chemical molecule structure analysis, Gas Chromatography-Mass Spectrometry (GC-MS) combines the functions of Gas Chromatography (GC) and Mass Spectrometry (MS). Drug detection, fire investigati on, environmental analysis, investigating explosives, and identifying unidentified materials are some applications of GC-MS. Utilizing its extensive network of laboratories, Infinita Lab, USA, provides this test to its clients in the USA and other locations. (infinitalab.com)
  • The Shimadzu GCMS-TQ8040 is the first Triple Quadrupole with Smart Productivity for high efficiency sample throughput, Smart Operation for quick and easy method development, and Smart Performance for low detection limits and Scan/MRM. (utm.my)
  • At three spiked levels, the recoveries of PCBs were 60.2%~103.2%, the relative standard deviations were 0.9%~14.0% ( n =3), and the detection limit of the method was 1.01~2.92 pg·L -1 . (bcdt.ac.cn)
  • 1987). These methods are not specific to guthion because these metabolites are produced from the breakdown of other organophosphate compounds as well. (cdc.gov)
  • At JEOL, Dr. Masaaki Ubukata's recent work on Automated Structural Analysis for Real Unknown Compounds combines artificial intelligence (AI) with GC-HRTOFMS to rapidly provide analysis results of known mass spectra, automatically perform qualitative analysis of unknown chemical compounds, and provide high quality structural analysis results. (jeolusa.com)
  • Prior to the development of our new software, structural analysis of real unknown compounds required significant knowledge, experience, and time: sorting through structural information for EI fragment ions, identifying higher-mass m/z ions as functional groups and substructures, looking at low-mass m/z fragment ions to classify compounds, and working through possible McLafferty rearrangement to derive structures from the fragmentation. (jeolusa.com)
  • While mass spectrometry can perform effective qualitative analysis, it is powerless for the analysis of complex organic compounds, while chromatography is an effective separation and analysis method for organic compounds and is particularly suitable for performing quantitative analysis of organic compounds, but qualitative analysis is more difficult. (antiteck.com)
  • Gas chromatography technique is to use the difference of distribution coefficients of different compounds in the mobile phase (carrier gas) and stationary phase at a certain temperature to make different compounds flow out in the column successively according to time, to achieve the purpose of separation and analysis. (antiteck.com)
  • All of the test compounds were eluted from the column and could be detected by UV spectrometry at a sample size of 5 nanograms on-column. (gla.ac.uk)
  • Five of the test compounds could be detected by fluorescence spectrometry and seven by ECD. (gla.ac.uk)
  • Mass Spectrometry works by ionizing chemical compounds to generate charged ions, with a range of molecular masses. (infinitalab.com)
  • Individual compounds have their own unique mass spectrum since every pure compound always produces the same family of ions. (infinitalab.com)
  • Organic methods include those under NIOSH and OSHA for industrial hygiene applications and EPA for environmental and stack emissions applications, including EPA 8265 for volatile compounds using direct sampling mass spectrometry. (azurewebsites.net)
  • Another method uses process mass spectrometers for direct real-time monitoring of compounds, which was approved by an EPA ruling in February 2018. (azurewebsites.net)
  • Northern ecosystems exchange climate-relevant trace gases with the atmosphere, including volatile organic compounds (VOCs). (copernicus.org)
  • The target compounds were isolated from sediment samples by ultrasound-assisted extraction method, followed by purification of extracts using open-column chromatography. (ubbcluj.ro)
  • We develop and optimize analytical methods for organic and organometallic compounds, using either liquid chromatography (UHPLC) or supercritical fluid chromatography (SFC) with MS and MS/MS characterization or quantification. (lu.se)
  • Gas chromatography mass spectrometry is also available for the analysis of volatile compounds, as well as a state-of-the-art pipetting robot for automated sample preparation. (lu.se)
  • This sensitive and robust triple quadrupole mass spectrometer is used for analysis of low (ppb) levels of environmental compounds and biomarkers. (lu.se)
  • Routine work includes determination of molecular formula and accurate mass with an accuracy of ± 1 mDa of compounds with m/z up to 3000 mDa. (lu.se)
  • These compounds have high vapor pressures with low water solubility and are emitted as gases from solids or liquids. (cdc.gov)
  • Aqueous root extract of P. zeylanica (PZRE) was analyzed for the presence of flavonoids, sugars, and organic acids using high-performance thin-layer chromatography (HPTLC), gas chromatography-time of flight-mass spectrometry (GC-TOF-MS), and biochemical methods. (dovepress.com)
  • Determination of 28 kinds of polychlorinated biphenyls in snow based on gas chromatography-quadrupole tandem time-of-flight mass spectrometry[J]. Journal of Glaciology and Geocryology, 2023, 45(1): 267-276. (bcdt.ac.cn)
  • Trapped ion mobility spectrometry (TIMS) combined with quadrupole time of flight mass spectrometry (Q-TOF). (lu.se)
  • While at Cornell, McLafferty assembled one of the first comprehensive databases of mass spectra and pioneered artificial intelligence techniques to interpret GC/MS results. (wikipedia.org)
  • The silver NPs (AgNPs), gold NPs (AuNPs), and bimetallic NPs (AgAuNPs) were synthesized from root extract and characterized using ultraviolet-visible spectra, X-ray diffraction (XRD), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), and dynamic light scattering (DLS). (dovepress.com)
  • Electron impact spectra were recorded at 70 ev for each of the derivatives of the test substances and possible fragmentation reactions giving rise to the most prominent ions in the spectra were proposed. (gla.ac.uk)
  • The prepared samples were identified by employing an analytical procedure where the analytes were investigated by gas chromatography-electron impact mass spectrometry (GC-EI-MS) and thus a library of mass spectra was created. (allaboutheaven.org)
  • Its electron impact mass spectra was, however, given and interpreted. (unibas.it)
  • Interpretation of mass spectra and data treatment will also be covered, together with practical aspects of mass spectrometry method development. (lu.se)
  • high-resolution transmission electron microscopy and various techniques characterized the synthesized AgNPs. (ijpsonline.com)
  • The purpose of this chapter is to describe the analytical methods that are available for detecting, measuring, and/or monitoring guthion, its metabolites, and other biomarkers of exposure and effect to guthion. (cdc.gov)
  • The intent is not to provide an exhaustive list of analytical methods. (cdc.gov)
  • Many of the analytical methods used for environmental samples are the methods approved by federal agencies and organizations such as EPA and the National Institute for Occupational Safety and Health (NIOSH). (cdc.gov)
  • Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). (cdc.gov)
  • 7. ANALYTICAL METHODS extraction (SPE) with a C18 cartridge or liquid-liquid microextraction (LLME) procedure prior to quantification. (cdc.gov)
  • Due diligence may also provide independent verification of novel analytical and imaging methods and may contribute to making analytical instruments cost-effective, accessible, and easy to use. (aspenquantum.com)
  • Prior to California's publication of the first draft SOPs for testing microplastics, and in the absence of a standard analytical method, a wide variety of sampling and analytical methods have been used in academic and research settings. (haleyaldrich.com)
  • The lack of a standardized analytical method provides one possible explanation for the wide ranges of microplastics concentrations reported in environmental media and the disparity in study results regarding the toxicity of microplastics. (haleyaldrich.com)
  • Fungal identification was achieved by scanning electron microscopy and molecular techniques, and mycophenolic acid production was confirmed by two analytical methods (gas and liquid chromatography coupled to mass spectrometry). (hal.science)
  • The effects of these NPs on Acinetobacter baumannii , Staphylococcus aureus , and Escherichia coli biofilms were studied using quantitative biofilm inhibition and disruption assays, as well as using fluorescence, -scanning electron microscopy, and atomic force microscopy. (dovepress.com)
  • A Current View of Scanning Electron Microscopy in Forensics. (news-medical.net)
  • The size distribution and morphology of the filler particles were analysed using scanning electron microscopy (n = 5). (bvsalud.org)
  • Mass Spectrometric Analysis. (wikipedia.org)
  • Mass spectrometry for small molecules includes an overview of mass spectrometric techniques that can be used for analysis of low molecular weight analytes in both the gas and liquid phase. (lu.se)
  • This report describes the development of a quantitative method for 2C-T-7. (erowid.org)
  • ISO 12010:2012 specifies a method for the quantitative determination of the sum of short-chain polychlorinated n ‑alkanes, also known as short-chain polychlorinated paraffins (SCCPs), in the carbon bond range n -C 10 to n -C 13 inclusive, in mixtures with chlorine mass fractions ("contents") between 49 % and 67 %, including approximately 6 300 of approximately 8 000 congeners. (iso.org)
  • For accurate quantitative or qualitative analysis, mass spectrometry is today combined with different chromatographic techniques. (lu.se)
  • Course organizer Peter Spégel Center for Analysis and Synthesis Department of Chemistry Lund University course gives theoretical and practical knowledge on how mass spectrometry can be used in qualitative and quantitative analyses of small molecules. (lu.se)
  • He is also known for electron-capture dissociation, a method of fragmenting gas-phase ions. (wikipedia.org)
  • The tandem mass spectrometer ran in Multiple Reaction Monitoring (MRM) mode where the precursor ions fragmented with nitrogen gas in the collision cell at a defined electron voltage. (cdc.gov)
  • The resultant product ions registered an interpretable signal via the electron multiplier. (cdc.gov)
  • The mass spectrometry technique converts vaporized sample molecules into charged ions in a high vacuum ion source, which are ionized, induced, and focused into a mass analyzer, where they are separated by a mass-to-charge ratio (ratio of mass to charge, m/z) under the action of a magnetic or electric field, in time sequence or spatial location, and finally detected by an ion detector. (antiteck.com)
  • The ions are then accelerated in an electric field and separated in vacuum, depending on their mass as well as their charge. (infinitalab.com)
  • The separated ions are analyzed by spectrometry principles. (infinitalab.com)
  • 2018). This method required the use of 0.50 mL of serum that was spiked with 40 µL of isotopically labeled internal standard before being hermetically sealed in a 10-mL SPME vial with a Teflon-lined silicone septum. (cdc.gov)
  • A number of method parameters were studied including internal standard selection, liquid-liquid extraction scheme, and drug stability in preserved refrigerated blood. (erowid.org)
  • The adopted method for blood and urine involves the addition of trimethoxyamphetamine TMA as internal standard, alkalinization with ammonium hydroxide, and liquid-liquid extraction with n-chlorobutane. (erowid.org)
  • The injector is divided into gas injector and liquid injector, and the gasification chamber is a device for instantaneous gasification of liquid samples. (antiteck.com)
  • Mass spectrometers equipped with atmospheric pressure ion sources (API-MS) have been designed to be interfaced with liquid chromatographs (LC) and have rarely been connected to gas chromatographs (GC). (aalto.fi)
  • The eluates were ionized at 70eV in the electron source of the mass spectrometer. (cdc.gov)
  • The full name of GC-MS is gas chromatography-mass spectrometry , which is an instrument that combines gas chromatography and mass spectrometer. (antiteck.com)
  • The basic components of a mass spectrometer are: ion source, mass filter and detector, which are placed in the vacuum master tube. (antiteck.com)
  • Interface: The sample from the GC enters the mass spectrometer through the interface, which is the key to the gas-mass spectrometry system. (antiteck.com)
  • GC-MS is generally composed of the following parts: chromatograph, interface part, mass spectrometer analyzer and computer data processing system. (antiteck.com)
  • and be analyzed in the gas chromatograph-mass spectrometer. (chinesestandard.net)
  • We report experimental measurements of ecosystem-scale VOC fluxes above a wheat field with a highly sensitive proton transfer mass spectrometer. (copernicus.org)
  • In this AI-assisted workflow, deconvolution of GC-MS data into mass spectrum, library search, molecular ion search, accurate mass analysis, isotope pattern matching, and structural analysis can all happen within minutes. (jeolusa.com)
  • Gas-Isotope-ratio mass spectrometry (G-IRMS) allows the precise measurement of mixtures of naturally occurring light stables isotopes. (lu.se)
  • Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. (cdc.gov)
  • Using a low thermal mass capillary column with a ramp rate of up to 2.5°C/s, the instrument can typically perform sample analysis in less than 5 minutes and up to 12 sample analyses per hour, providing a fast solution for field testing. (antiteck.com)
  • Hybrid methods, such as gas chromatography-mass spectrometry, provide robust tools for complex sample analysis. (aspenquantum.com)
  • For the component analysis, methanol eluates from the light-polymerised composites were evaluated by gas chromatography/mass spectrometry (n = 3). (bvsalud.org)
  • To ensure the best analysis selection, the Pace® team will discuss the reporting criteria needs for each site being evaluated to assist in guiding the best selection of either Aroclor or congener-specific methods. (pacelabs.com)
  • After completing ion chromatography (IC) analysis , we found the concentration of the cleaning agent was at 4.37pm, indicating it was not completely removed prior to shipment. (innovatechlabs.com)
  • These methods provide regulatory support for the use of the Proton Transfer Reaction Mass Spectrometry (PTR-MS) systems for the real-time, ultra-trace analysis of volatiles in air matrices. (azurewebsites.net)
  • The program is waiting for approval of an ASTM method for VOCs analysis by PTR-MS related to vapor intrusion, to be used in numerous applications. (azurewebsites.net)
  • The instrument enables mass spectrum measurement for qualitative analysis or identification of unknowns and Selected Ion Monitoring (SIM) and MRM Measurement for quantitation of trace elements. (utm.my)
  • It has several methods of analysis that makes it different and powerful instrument for sample analysis. (utm.my)
  • Since only the volatiles are sampled, headspace analysis is ideal for dirty samples (e.g. blood, plastics, cosmetics), solid materials, samples with high boilers of no interest, samples with high water content, or samples that are difficult to handle by conventional chromatographic methods. (utm.my)
  • However, the study demonstrates that the analysis of POP residues in sediments is a suitable method for reconstructing the history of surface water pollution. (ubbcluj.ro)
  • This method can be applied to the analysis of snow samples, which provides a basis for further analysis of the distribution characteristics of pollutants in snow. (bcdt.ac.cn)
  • This course covers modern mass spectrometry with a particular focus on the analysis of low molecular weight analytes. (lu.se)
  • Practical parts include analysis of own or supplied samples by chromatography and mass spectrometry, with subsequent data analysis and identification of sample components. (lu.se)
  • The course covers the basics, principles and limitations for the most common methods for multivariate statistics (analysis of variance, principal component analysis and partial least squares regression), experimental design (super-saturated and factorial designs) and method validation with a focus on practical use. (lu.se)
  • Impurities of interest are extracted from an alkaline solution (pH 12.8) by diethyl ether and submitted to gas chromatography (GC)-mass spectrometry (MS) analyses. (erowid.org)
  • As the field grows more and more technically advanced, demand is increasing for forensics experts trained in advanced scientific methods. (worldwidelearn.com)
  • The most utilised techniques in forensics and toxicology include spectrophotometry, chromatographic methods, immunologic methods, and gas chromatography/mass spectrometry amongst others. (news-medical.net)
  • Forensics Identification in Mass Disasters. (news-medical.net)
  • Different types of mass analysers will also be discussed, including the quadrupole, the 3d and linear ion traps, the time of flight, the orbitrap and the Fourier transform ion cyclotron resonance mass analysers, and their combinations. (lu.se)
  • With the high resolution of GC and the high sensitivity of mass spectrometry, they are effective tools for the characterization and quantification of drugs and metabolites in biological samples. (antiteck.com)
  • For Solid Phase Micro Extraction (SPME), it is an equilibrium sampling method and can be used for gases, solids (Headspace) and liquids (direct). (utm.my)
  • General method for determining ethylene oxide and related N7-guanine DNA adducts by gas chromatography-electron capture mass spectrometry. (cdc.gov)
  • 2001). For human serum samples, the authors determined that the SPE extraction procedure was the preferred method since it was faster, less tedious, and avoided the formation of emulsions that were frequently encountered in the LLME procedure. (cdc.gov)
  • As a fully self-contained field analyzer, it can operate for up to 2.5 hours on battery power, while the built-in gas cylinder can accommodate approximately 150 samples. (antiteck.com)
  • A sensitive and specific gas chromatography-mass spectrometry (GC-MS) method for the determination of amphetamine (AM), methamphetamine (MA), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA) and methylenedioxyethylamphetamine (MDEA) in whole blood was designed, using the respective pentadeuterated analogs of the analytes as internal standards (I.S.). After alkalinisation of blood samples, the amphetamines were extracted using diethyl ether, derivatized with heptafluorobutyric anhydride, then purified by successive washings with deionized water and 4% NH4OH. (erowid.org)
  • The method can be applied to samples containing 0,1 µg/l to 10 µg/l. (iso.org)
  • The stratigraphy of the background was determined from samples mounted as cross-sections, and its material composition was analysed using electron microscopy and chromatographic techniques. (springeropen.com)
  • The cost per sample varies considerably depending on the method used, the type of samples, if you want us to make some part of the pre-treatment, etc. (lu.se)
  • Laboratory: basic techniques and synthetic procedures and modern spectroscopic methods of structure determination. (beloit.edu)
  • IEC 62321-10 -2020 pdf free.Determination of certain substances in electrotechnical products - Part 10: Polycyclic aromatic hydrocarbons (PAHs) in polymers and electronics by gas chromatography-mass spectrometry (GC-MS). These test methods have been evaluated for use with plastics and rubbers. (yufakejian.cn)
  • Electrochemical synthesis has emerged as an alternative method to mitigate common challenges associated with organic synthesis. (trentu.ca)
  • Supporting activities include the development of epidemiological, experimental laboratory, and risk-assessment methods that could produce internationally comparable results, and the development of manpower in the field of toxicology. (inchem.org)
  • A profiling method for the identification of impurities found in seized 3,4-methylenedioxymethamphetamine (MDMA) tablets is presented. (erowid.org)
  • The method was linear from this limit up to 1000 ng/ml for all analytes, with good intra-assay precision and good intermediate precision and accuracy over these ranges. (erowid.org)
  • For a deeper insight into chromatography the LifeScience course "Bioanalytical HPLC" is recommended. (lu.se)
  • During this time, he developed the first GC/MS instruments and developed techniques for determining the structure of organic molecules by mass spectrometry, most notably in the discovery of what is now known as the McLafferty rearrangement. (wikipedia.org)
  • These test methods have been evaluated for use with ABS (acrylonitrile butadiene styrene) containing individual PAHs ranging from 37.2 mglkg to 119 mg/kg and rubbers containing individual PAHs ranging from 1 mg/kg to 221,2 mg/kg. (yufakejian.cn)
  • Meanwhile, progress in microscopy, including electron and scanning probe microscopy, enables atomic and molecular-scale visualization. (aspenquantum.com)
  • It was concluded that GC-MS was the only method which would have sufficient selectivity and separating ability for use in a screening procedure and this method was used in the rest of the study. (gla.ac.uk)
  • Gas Chromatography utilizes the principle that intermolecular (physical adsorption) forces between molecules in a gas and a solid surface depend upon the molecular structure and the nature of the solid surface. (infinitalab.com)
  • The MIPs are produced by various polymerization methods but in all cases specifi c interactions, molecular partitioning and polymer structure are key properties that we focus on. (lu.se)
  • Terpenes and their derivatives are common tropospheric trace gases (Graedel, 1979). (cdc.gov)
  • As different bacterial species produce AHL analogs that differ in length of the N-acyl chain, ranging from 4 to 14 carbons and in the substitution at the C-3 position of the side chain (i.e., oxo or hydroxyl group), the suitability and applicability of a gas chromatography-mass spectrometry direct method for characterizing trace amounts of AHLs was evaluated using N-heptanoyl-homoserine lactone as internal standard. (unibas.it)
  • As discussed in our previous article, Senate Bill 1422 requires the California State Water Resources Control Board (Board) to establish and adopt standard methods for testing microplastics in drinking water. (haleyaldrich.com)
  • Mass Spectrometers can work in both full scan and selective ion monitoring (SIM) modes. (infinitalab.com)
  • The mass differences between isotopes leads to quantifiable kinetic- or mass dependent fractionation that is characteristic of the biological, chemical or physical history of a sample. (lu.se)
  • Extraction recoveries were 85.2% for AM, 90.9% for MA, 76.5% for MDA, 84.1% for MDMA and 63.6% for MDEA. (erowid.org)
  • Gas Chromatography-Mass Spectrometry (GC-MS) utilizes Gas chromatography (GC) to separate a chemical mixture into individual molecules followed by Mass spectrometry (MS) to identify the molecules. (infinitalab.com)
  • The molecules carried in the gas (termed mobile phase), are eluted at different times from the column depending on the affinity of molecules for the stationary phase. (infinitalab.com)
  • Occurrence of N-Acyl-L-Homoserine Lactones in Extracts of Some Gram-Negative Bacteria Evaluated by Gas Chromatography/Mass Spectrometry. (unibas.it)