An Improved High Performance Liquid Chromatographic Method for Tryptophan Analysis in Rat Brain Administrated by Seaweed Abstract.
Indirect evidence has implicated a role for central angiotensin II in blood pressure control. To answer directly the question of whether angiotensin II exists in the brain, independent of blood-borne angiotensin, and to quantify the amounts in different parts of the central nervous system, a sensitive radioimmunoassay was used to measure extracts of male adult rat brain hypothalamus and cortex after purification with high pressure liquid chromatography with a high recovery. The fractions coeluted with authentic angiotensin. Rats were nephrectomized bilaterally, and 24 hours later the brains were extracted in acetic acid and boiled. SepPak C-18 purification preceded reverse phase high pressure liquid chromatography. High pressure liquid chromatography revealed two peaks, one which comigrated precisely with [Ile5] angiotensin II, and another smaller peak which overlapped with [Ile5] angiotensin III. The highest levels were found in the hypothalamus (125 pg/g tissue), pituitary (190 pg/g tissue), ...
The formation of 7-hydroxywarfarin in incubations of (S)-warfarin with human liver microsomes reflects their cytochrome P-4502C9 activity. This paper describes a rapid high-performance liquid chromatographic method for the determination of 7-hydroxywarfarin with high sensitivity, selectivity, and a …
TY - JOUR. T1 - Linear and quadratic relationships between retention and organic modifier content in eluent in Reversed Phase High-Performance Liquid Chromatography: A systematic comparative statistical study. AU - Baczek, T.. AU - Markuszewski, M.. AU - Kaliszan, R.. AU - Straten, van, M.A.. AU - Claessens, H.A.. PY - 2000. Y1 - 2000. N2 - Statistical evaluation of linear and quadratic models of chromatographic retention was performed. The relationships describing retention were derived for a set of 23 carefully selected test analytes chromatographed on 18 HPLC columns using methanol-water or acetonitrile- water solutions as mobile phase. It was ascertained whether the square term in the quadratic model improves the description of chromatographic retention in a statistically significant manner. It was also checked whether the retention data extrapolated to a hypothetical neat water eluent (log kw) obtained with the two models and the two organic modifiers are equivalent or should be considered ...
TY - JOUR. T1 - Determination of transdermal sildenafil in nude mouse skin by reversed-phase high-performance liquid chromatography. AU - Liaw, Jiahorng. AU - Chang, Ting Wei. PY - 2001/12/25. Y1 - 2001/12/25. N2 - A simple and sensitive high-performance liquid chromatographic method was developed for the determination of sildenafil transdermal permeation of nude mouse skin. A reversed-phase column with UV detection at 224 nm was used for chromatographic separation. The mobile phase consisted of 32% acetonitrile with 0.2% phosphoric acid in water at pH 5.3 adjusted with 10 M NaOH with the flow-rate set at 1.0 ml/min. The limit of quantitation achieved was 5 ng/ml, and the calibration curve showed good linearity over the concentration range of 5-500 ng/ml. The relative standard deviations of within- and between-day analyses were all within 15%. Sildenafil was found to be stable between pH 3 and 12 during 24-h incubation with skin. After transdermal administration of 15.8 μg/ml of sildenafil to ...
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A new high-performance liquid chromatographic method was developed for quantification of midazolam in plasma samples from intensive care unit patients on long-term intravenous infusion of this benzodiazepine. Plasma samples (0.5 ml) were mixed with 1 microgram flurazepam (internal standard), alkalinized with 2.5 N NaOH, and extracted with toluene. The organic phase was evaporated to dryness, and the residue was dissolved in the mobile phase (acetonitrile/0.05 M phosphate buffer pH 4.5) and injected into the analytical column (C18 Nova-Pak 3.9 x 150 mm, 4 microns, maintained at room temperature; mobile phase flow rate: 1.2 ml/minute). The eluate was monitored at 207 nm, which reduced the risk of interferences from concurrent medications. Retention times of flurazepam, 1-hydroxymidazolam (an active metabolite) and midazolam were approximately 4.5, 6.1 and 13.5 minutes, respectively. The assay was linear over the range 100 to 3000 ng/ml. The coefficients of variation of the within-day and ...
A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) method was developed for the determination of terazosin in human plasma. The method involves a one-step single solvent extraction procedure using dichloromethane with a 0.25 ml plasma sample. Recovery values were all greater than 90% over the concentration range 0.25-100 ng/ml. Terazosin was found to adsorb to glass or plastic tubes, but this could be circumvented by using disposable plastic tubes. Also, rinsing the injector port with methanol after each injection helped to prevent any carry-over effect. The internal standard, prazosin, did not exhibit this problem. The method has a quantification limit of 0.25 ng/ml. The within- and between-day coefficient of variation and accuracy values were all less than 7% over the concentration range 0.25-100 ng/ml and hence the method is suitable for use in pharmacokinetic studies of terazosin.
The High Performance Liquid Chromatography HPLC is a really important technique employed in analytical chemistry and can be used to separate a mixture component, identify and measure all the elements found in the mix. The ratio between the concentration of a chemical being analyzed into the response of this sensor to that compound is commonly referred as the response element. This is because each element is known to interact differently with the adsorbent material hence resulting to some diverse flow rates of these components thereby easing the separation of the stated components of a mixture. This technique has hence found immense use in medical units as well as in manufacturing plants for a variety of uses. The response factor is obtained by dividing the concentration by the summit area. For example when a solution comprising three materials is being handled, it is easier to separate these elements by immersing it in an adsorbent material and then injecting it into the HPLC.. It is expected ...
The general aim of this thesis was to evaluate a newly designed and constructed miniaturized rotating disk apparatus for in vitro dissolution rate measurements of different drug substances from all of the classes in the Biopharmaceutical Classification System (BCS). The new equipment is based on a low volume flow-through cell of Plexiglas, a gold plated magnetic bar and a special designed press. The disk of drug substance (approx. 5 mg) is placed eccentrically in the bar. Rotation speeds were set with a graded magnetic stirrer. An external HPLC pump delivered a continuous flow of aqueous medium to the flow-through cell during dissolution testing.. A reversed phase high-performance liquid chromatography system using diode array detection (RP-HPLC-DAD) was coupled online to the new equipment. The injections from the miniaturized rotating disk outlet into the quantifying HPLC system were controlled by a six-position switching valve. The injection volumes from the valve and the autosampler, used for ...
Determination of free urinary cortisol is a test of choice in the diagnosis of Cushings syndrome. In this study, cortisol was quantified using reversed-phase high-performance liquid chromatography (RP-HPLC) in urine samples previously extracted with ether and using triamcinolone acetonide as internal standard (IS). A BDS-Hypersil-C18® column, water-acetonitrile (72:28; v/v), with a flow rate of 1.0 mL/min and detection at 243 nm were used. This method showed to be both effective and efficient, with sensitivity and linearity ranging from 2.50 to 150 μg/L, and can be used in substitution to the radioimmunoassay technique within this concentration range ...
Oxygenated polyunsaturated fatty acids (PUFAs)play an outstanding role in the physiological and pathological regulation of several biological processes. These oxygenated metabolites can be produced both enzimatically, yielding almost pure enantiomers, and non-enzymatically. The free radical-mediated non-enzymatic oxidation commonly produces racemic mixtures which are used as biomarkers of oxidative stress and tissue damage. The biological activity of oxygenated PUFAs is often associated with only one enantiomer, making it necessary of availing of lipidomics platforms allowing to disclose the role of single enantiomers in health and disease. Polysaccharide-based chiral stationary phases (CSPs) play a dominating part in this setting. As for the cellulose backbone, 4-methylbenzoate derivatives exhibit very high chiral recognition ability towards this class of compounds. Concerning the phenylcarbamate derivatives of cellulose and amylose, the tris(3,5-dimethylphenylcarbamate) variants show the best ...
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We describe a simple, sensitive, and specific high-performance liquid-chromatographic method with ultraviolet detection (256 nm) for the simultaneous analysis of nicotine and cotinine in urine of passive smokers. The analytes are extracted and purified from the complex and impure matrix in two stages; first, by liquid-liquid extraction and followed by solid-phase extraction (C2 column). We used a DB C8 5-microns-particle column (25 x 0.46 cm) and a mobile phase of phosphate-citrate buffer and acetonitrile (91:9 by vol) containing 5 mL of triethylamine and 600 mg of heptanesulfonate per liter, adjusted to pH 4.4, to separate the compounds. Two internal standards (2-phenylimidazole and N-ethylnorcotinine) were used. The detection limit of the HPLC assay was less than 1 microgram/L for both analytes. The average interassay CV for nicotine was 7.6%, for cotinine 6.5%, in the concentration range 0-60 micrograms/L. The mean analytical recovery of nicotine with respect to the internal standard ...
A fully automated and validated 2D online solid-phase extraction (SPE) high-performance liquid chromatographic method was described for the direct simultaneous determination of clenbuterol (CLEN) and doxazosin (DOX) in spiked human plasma samples. Chromatographic separation of the analytes was achieved by column-switching. SPE column packed with restricted access material for depleting matrix and a reversed phase HPLC column for eluting analytes were used with UV detection on 250 nm. A 10 mM acetate buffer (pH: 4) and acetonitrile mixture was used in gradient elution with 1 mL/min flow rate, as mass spectrometry friendly mobile phase. Calibration graphs were prepared for spiked plasma, and good linearity was achieved over a dynamic range of 75.0 ng/mL-200.0 mu g/mL for CLEN and 37.5 ng/mL-100.0 mu g/mL for DOX. Detection and quantification limits were 8.47 and 11.94 ng/mL, 25.66 and 36.18 ng/mL for CLEN and DOX, respectively. Online column-switching liquid chromatography technique combines the ...
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This article details the elements used in the method verification for the simultaneous high performance liquid chromatography (HPLC) assay of Pentoxifylline, Mupirocin, Itraconazole, and Fluticasone Propionate in Humco™ Lavare Wound base. The method was proven to be linear over 50%-150% of the nominal concentration of the standards. The method was proven to be accurate over 50%-150%, with 98%-102% recovery of the actives from spiked placeboes over that range. The method was shown to be specific to the analytes listed and precise, yielding acceptable results for system reproducibility and method repeatability. The method, as written, is considered to have been verified.
A novel and generally applicable approach was established to hierarchically identify the bioactive components of a medicinal herb by preparative high-performance liquid chromatography (prep-HPLC) and a selective knock-out strategy. In this study, the targeted components of an herbal medicine were separated and knocked out using prep-HPLC. Subsequently, the contributions of the different target components to the overall effect of the medicinal herb were comparatively evaluated and differentiated by a heat map and a 3D score plot. This approach was successfully applied to investigate the bioactive constituents of safflower. The contributions of 11 components to the overall effect of safflower were as follows: anhydrosafflor yellow B(10)>6-hydroxykaempferol 3,6-di-O-beta-D-glucoside (8 > hydroxysafflor yellow A (3)> kaempferol 3-O-beta-rutinoside (11)> 6-hydroxykaempferol 3-O-beta-rutinoside (9)> 6-hydroxykaempferol 3,6-di-O-beta-D-glucoside-7-O-beta-D-glucuronide (4)> 6-hydroxyapigenin ...
An HPLC method for profiling 13 phytoestrogens and their metabolites using coulometric electrode array detection was developed. Sensitivity of the method was slightly less than that of our GC-MS method, but significantly higher compared to the HPLC methods using diode-array or UV detection. Detectio …
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Background: Losartan potassium is a non-peptide AT1 receptor drug used in the treatment of hypertension. Methods: A simple, rapid, sensitive, and validated isocratic reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method was developed and validated for the determination of losartan potassium (LOS) in bulk drug and tablets. The assay was developed using Waters Acquity BEH C18 (100 mm × 2.1 mm), 1.7-μm column with a mobile phase consisting of a mixture of phosphate buffer (pH 3.2) and acetonitrile (50:50 v/v). Results: An assay with a total run time of only 5 min was developed. The method monitored at 245 nm exhibited linearity over a concentration range of 2.0 to 15.0 μg mL−1 LOS. The limits of detection and quantification (signal-to-noise ratio (S/N) = 10) were found be 0.018 and 0.054 μg mL−1 , respectively. The intraday and interday RSDs were less than 1.0%. The method was validated by the determination of LOS levels in tablets where the percentage on the label claim ...
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GE AKTA fast protein liquid chromatography system is an eagle-i resource of type Fast protein liquid chromatography instrument at Universidad Central del Caribe.
The nearly 50% production capacity increase is in response to growing global demand for purification media from the antibody drug manufacturing industry.. At a cost of approximately ¥5 billion, the Nanyo Complexs Toyopearl production facilities are being expanded. Construction began in October 2016 and is slated for completion in August 2018. Commercial operations at the expanded production facilities are expected to commence in April 2019.. Liquid chromatography separation and purification media are used in the production of biopharmaceutical ingredients. Employing differences in charge, hydrophobicity, specific affinity, and molecular size, these media are designed to separate and purify target components. Given the rapid growth of the market for biopharmaceutical products, in Japan, the United States, and countries in Europe and in China, India, and other emerging nations, these media are in high demand. And Tosoh is committed to meeting that demand.. With its high strength, superior ...
China High Performance Liquid Chromatography, Spectrophotometer, HPLC (RAY-230 HPLC), Find details about China High Performance Liquid Chromatography, Spectrophotometer from High Performance Liquid Chromatography, Spectrophotometer, HPLC (RAY-230 HPLC) - Raylabel Instrument Co., Ltd.
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Background: Elevated circulating levels of BNP as detected on commercial antibody-based assays in heart failure (HF) patients may reflect a mixture of degraded BNP fragments, rather than intact BNP1-32.. Methods: Blood samples from 20 HF patients were collected, immediately centrifuged with plasma promptly aliquoted and frozen at -80°C. In a single thaw, 50uL of 10N HCL was added to 200 uL of plasma, incubated for 10 minutes then centrifuged. 100 uL of supernatant was injected into liquid chromatography mass spectrometry system. On-line extraction and high performance liquid chromatography methods were optimized using Onyx C18 guard and analytical column. Purified synthetic BNP1-32 was then incubated in patient serum and BNP fragments identified. Lastly, a proprietary protocol to inhibit BNP degradation was developed.. Results: The estimated limit of detection of the mass spectrometry method was 0.78 ng/mL and the lower limit of quantitation was 1.5 ng/mL with a good linear relationship ...
Reverse phase High Performance Liquid Chromatography on cyanopropyl-modified silica stationary phase, containing lipophilic and polar moieties, is used. While passing through the column among with the mobile phase the test substance interacts with the stationary phase. As a result of the partitioning between the mobile and stationary phase the test substance is retained. The dual-composition of the stationary phase having polar and non-polar sites allows for interaction of polar and non-polar groups of a molecule in a similar way as it is the case for organic matter in soil or sewage sludge matrices. This enables the relationship between the retention time on the column and the adsorption coefficient on organic matter to be established. ...
Biodistribution and metabolism of oligonucleotides were determined using a 3H-labeled 20-nucleotide phosphodiester and its phosphorothioate analog. The oligonucleotides were radiolabeled by 3H-methylation of an internal deoxyctidine with HhaI methylase and S- [3H]adenosylmethionine. Biodistribution studies were conducted after intravenous injection of 6 mg/kg (5 muCi) oligonucleotide. Metabolism of the oligonucleotides was determined by paired-ion high performance liquid chromatography. After phosphodiester injections, radiolabel rapidly cleared the blood. Relative initial concentrations were as follows: kidney , blood , heart , liver , lung , spleen. Radiolabel in spleen peaked at 1 hr and remained elevated for 24 hr. At 2 hr the concentration in all organs, except spleen, was equal to that in blood. High performance liquid chromatographic analysis of the kidney, liver, and spleen extracts and urine indicated extremely rapid metabolism to monomer. Results of studies after the injection of ...
A Simple, fast and precise reverse phase high performance liquid chromatographic method is developed for the simultaneous determination of Rosuvastatin Calcium and Fenofibrate. Chromatography was carried out at 400C and Separation of these drugs were performed on BDS C18 column (250 x 4.6 mm, 5 µ) as stationary phase with a mobile phase comprising of Acetonitrile: water (pH adjust to 2.5 with O-Phosphoric Acid) in the ratio of 70:30 (v/v) at a flow rate of 1.5 ml/min and Detection wavelength of Rosuvastatin Calcium and Fenofibrate ware 287nm. The Retention time for Rosuvastatin Calcium and Fenofibrate were 2min and 8.5min respectively. The linearity of Rosuvastatin Calcium and Fenofibrate was in the range of 1 to 5 µg/mL. The recovery was calculated by standard addition method. The proposed method was found to be accurate, precise and rapid for simultaneous determination of Rosuvastatin Calcium and Fenofibrate. It can be used for routine analysis.
TSKgel ODS-100V and TSKgel ODS-100Z columns incorporate the best-in-class surface properties to limit secondary interactions of basic, acidic and chelating compounds. Take advantage of the benefits of high column efficiency and symmetrical peak shapes to reduce your analysis and method development time! The ultra high purity Type B base silica contains negligible amounts of metal ion impurities. Combined with monomeric bonding chemistry, this silica makes the best general purpose Reversed Phase columns suitable for the most demanding separations in quality control as well as in research and development. TSKgel ODS-100V columns have a lower carbon content than ODS-100Z columns, making the bonded phase surface 100% water wettable and the preferred choice to retain polar metabolites.
Academic Journals Database is a universal index of periodical literature covering basic research from all fields of knowledge, and is particularly strong in medical research, humanities and social sciences. Full-text from most of the articles is available. Academic Journals Database contains complete bibliographic citations, precise indexing, and informative abstracts for papers from a wide range of periodicals.
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A simple and precise high performance liquid chromatography method for determination of candesartan cilexetil in their pharmaceutical formulation was developed and validated. The separation was carried out on Cosmosil C18 (250mm X 4.6, 5μ) RP-HPLC column using an 0.8ml/min as flow rate with methanol: water (80: 20 v/v) mobile phase. Quantification was performed with a UV detector at 214nm, solubility and stability was determined individually in simulated biological fluids at various pH was investigated. The calibration curves of candesartan cilexetil were linear in the range of 10-50 μg/ml (R²=0.999). The developed method was applied to pharmaceutical formulation successfully with no interfering peaks. The percentage recovery was 99.71-100.29%. It was observed that solubility of candesartan cilexetil was increased in all invitro medium, in 1.2 and slightly 7.4 pH and the stability of candesartan cilexetil was stable in pH 1.2 or degraded in pH 7.4 for 24 hours.
LiChrospher® HPLC Columns: LiChrospher® is a reliable and versatile traditionally produced spherical silica carrier with a particle size of 5µm or 10 µm, providing well balanced pressure / separation performance ratio. A broad range of modifications on LiChrospher® are very widely used by HPLC-users all over the world for a broad range of applications. LiChrospher® sorbents are available as reversed phase derivatives (RP-8, RP-18 endcapped, RP-18, RP-18 endcapped and RP-select B), medium polar (NH2, CN, DIOL) and polar derivatives (Si 60). Furthermore LiChrospher® PAH is highly efficient and selective for the separation of PAH; LiChrospher® WP is very well suited for the separation of peptides and low molecular weight proteins. LiChrospher® sorbents are available as Hibar® RT columns or as LiChroCART® cartridges in different lengths ans internal diameters. To operate with LiChroCART® cartridges, the cartridge holder manu-CART® has to be used.
MODEL RELEASED. (High pressure liquid chromatography) Biochemist analyses a new compound synthesized by microcide chemists for its interaction with biological macromolecules using HPLC. - Stock Image C009/4186
denaturing high performance liquid chromatography释义,背景概述,例举denaturing high performance liquid chromatography相关的SCI文献,让我们更理解denaturing high performance liquid chromatography的应用.
This paper reports the utilization of 2-pyrrolecarboxaldehyde-4-phenylsemicarbazone (PPS) as a complexing reagent for the simultaneous determination and separation of Ni(II), Cu(II), Pd(II), and Ag(I) by reversed-phase high-performance liquid chromatography with UV detector. A good separation was achieved using Microsorb C18 column (150 × 4.6 mm i.d.) with a mobile phase consisted of methanol : acetonitrile : water : sodium acetate (1 mM) (68 : 6.5 : 25 : 0.5 v/v/v/v) at a flow rate of 1 mL/min. The detection was performed at 280 nm. The linear calibration range was 2–10 |i|μ|/i|g/mL for all metal ions. The detection limits (S/N = 3) were 80 pg/mL for Ni(II), 0.8 ng/mL for Cu(II), 0.16 ng/mL for Pd(II), and 0.8 ng/mL for Ag(I). The applicability and the accuracy of the developed method were estimated by the analysis of Ni(II) in hydrogenated oil (ghee)
Fish oil made from menhaden (Brevoortia tyrannus) can be used as a dietary supplement for the presence of high levels of the long-chained omega-3 fatty acids, viz. epentaenoic and docosahexanoic. In this work, for the first time, two different multidimensional approaches were developed and compared, in terms of peak capacity, for triacylglycerol characterization. In particular, silver ion chromatography with a silver-ion column and non-aqueous reverse-phase liquid chromatography with a C18 column were tested in both comprehensive (stop-flow) and off-line modes. The use of mass spectra attained by atmospheric pressure chemical ionization for both LC approaches, and the fatty acids methyl esters profile of menhaden oil obtained by gas chromatography analysis, greatly supported the elucidation of the triacylglycerol content in menhaden oil. The off-line approach afforded a better separation and, thus, higher peak capacity to allow identifying and semiquantifying more than 250 triacylglycerols. Such a huge
Definition : High-pressure packed-column liquid chromatography systems in which the packing of the column is made of microparticulate silica gel. The functional groups of the stationary phase may be polar relative to those of the mobile phase (i.e., normal bonded-phase chromatography) or, more usually, nonpolar (i.e., reverse bonded-phase chromatography).. Entry Terms : Reverse-Phase Liquid Chromatography Systems , Normal-Phase Liquid Chromatography Systems , Bonded-Phase Liquid Chromatography Systems. UMDC code : 18278 ...
A unique polypeptide, called enhancing factor (EF), which enhances the binding of labeled epidermal growth factor (EGF) to cells, has been isolated. It has been purified to homogeneity from the acid-soluble proteins of mouse intestines. Earlier, EF was partially purified by two cycles of gel-permeation chromatography on Bio-Gel columns. We now report the final purification of EF on high-performance liquid chromatography (HPLC), using a reverse-phase column (μBondapak C18). The purity of the protein was confirmed when a single peak was obtained in HPLC. Also, a single protein band was obtained in SDS-PAGE. Purified EF has the same properties in vitro as those reported earlier for partially purified EF. ...
A simple and rapid extraction procedure was developed for determining aldehydes in rainwater samples. This extraction technique involved the use of micro-solid-phase extraction in which the sorbent was held within a polypropylene membrane envelope, followed by high-performance liquid chromatographic analysis. Aldehydes such as formaldehyde, acetaldehyde, propionaldehyde and valeraldehyde were used as model compounds. Extraction conditions were optimized. The method linearity ranged between 0.5 and 50μgl-1 with the correlation coefficient of 0.987-0.999. The relative standard deviations (RSDs) of the method ranged from 7 to 12%. Method detection limits were in the range of 0.07-0.15μgl-1, which is lower than those previously reported for solid-phase microextraction combined with gas chromatography-mass spectrometric techniques. The proposed extraction technique was used for determination of aldehydes in rainwater samples to demonstrate the applicability of the method. © 2010 Elsevier B.V ...
A simple and reliable reversed-phase high-performance liquid chromatographic (HPLC) method for the routine determination of vitamins A and E and β-carotene in plasma (or serum) with wavelength-programmed ultraviolet-visible absorbance detection is described. A 200-μl aliquot of serum or plasma sample, after deproteinization with ethanol, and containing tocopherol acetate as internal standard, was extracted with butanol-ethyl acetate. Sodium sulphate was added for dehydration. Analytes of extracted samples were found to be stable for at least four days. A 10-μl aliquot of this organic extract was used for HPLC analysis. The mobile phase was methanol-butanol-water (89.5:5:5.5, v/v) and the flow-rate was set at 1.5 ml/min. The analytes of interest were well separated from other plasma constituents within 22 min at 45°C. The lowest detection limits of vitamins A and E and β-carotene were 0.02, 0.5 and 0.1 μg/ml, respectively. The recovery and reproducibility of the present method were around ...
The next-generation Thermo Scientific Vanquish Duo UHPLC systems are designed to maximize throughput and return on investment (ROI), while providing scientists with a robust and comprehensive understanding of their samples. The systems, which were introduced in February 2018, are on display at Analytica 2018 (Messe München, booth 101, hall B1) in Munich, Germany.. The increasing demand being placed on the pharmaceutical and biopharmaceutical industry to deliver safe and effective medicines that meet regulatory standards is presenting a unique set of analytical challenges, said Fabrizio Moltoni, vice president and general manager, HPLC, chromatography and mass spectrometry, Thermo Fisher Scientific. The Vanquish Duo UHPLC systems provide a high-throughput and robust solution required to enable full characterization of small and large molecules in a manner that creates confidence and quality, while helping to protect customers investment.. Each system in the Vanquish Duo UHPLC family enables ...
The presence of 6-methyladenine and 5-methylcytosine at Dam (GATC) and Dcm (CCA/TGG) sites in DNA of mycobacterial species was investigated using isoschizomer restriction enzymes. In all species examined, Dam and Dcm recognition sequences were not methylated indicating the absence of these methyltransferases. On the other hand, high performance liquid chromatographic analysis of genomic DNA from Mycobacterium smegmatis and Mycobacterium tuberculosis showed significant levels of 6-methyladenine and 5-methylcytosine suggesting the presence of DNA methyltransferases other than Dam and Dcm. Occurrence of methylation was also established by a sensitive genetic assay. ...
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Free Essays from Cram | Raju Chandra et al; A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the...
TY - JOUR. T1 - Hard modelling methods for the curve resolution of data from liquid chromatography with diode array detector and on-flow liquid chromatography with nuclear magnetic resonance spectroscopy. AU - Wasim, M. AU - Brereton, RG. N1 - Publisher: Amer. Chemical Soc. PY - 2006/4. Y1 - 2006/4. U2 - 10.1021/ci050112f. DO - 10.1021/ci050112f. M3 - Article (Academic Journal). VL - 46(3). SP - 1143. EP - 1153. JO - Journal of Chemical Information and Modeling. JF - Journal of Chemical Information and Modeling. SN - 1549-9596. ER - ...
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