Enrichment and purification of gardenia yellow from Gardenia jasminoides var. radicans Makino. by column chromatography technique

Publication year: 2012Source:Journal of Chromatography BJian-Fang Chen, Gui-Ming Fu, Yin Wan, Cheng-Mei Liu, Jian-Xin Chai, Hong-Ge Li, Jian-Tao Wang, Ming-Hu, Lun-Ning Zhang In present study, the performance and separation charac…

Publication year: 2012
Source:Journal of Chromatography B

Jian-Fang Chen, Gui-Ming Fu, Yin Wan, Cheng-Mei Liu, Jian-Xin Chai, Hong-Ge Li, Jian-Tao Wang, Ming-Hu, Lun-Ning Zhang

In present study, the performance and separation characteristics of nine macroporous resins for the enrichment and purification of gardenia yellow from Gardenia jasminoides var. radicans Makino have been evaluated. The adsorption and desorption properties of crude gardenia yellow solution on macroporous resins including HPD722, HPD100, HPD100A, HPD400, HPD400A, D101, AB-8, XAD-16, and NKA-9 have been compared. Then, HPD722 was chosen to purify gardenia yellow because of its strong adsorption and desorption abilities as well as high selectivity. Column packed with HPD722 resin was used to perform dynamic adsorption and desorption tests to optimize the separation process of gardenia yellow. The optimal conditions were as follows: The crude gardenia yellow solution with concentration of 15mg/mL was loaded in column packed with HPD722 resin at the flow rate of 1.0mL/min, and the adsorbate-laden column was washed with 800mL water, 600mL 15% ethanol water solution respectively at the speed of 2.5mL/min, then desorbed with 200mL 80% ethanol water solution at the speed of 3.5mL/min. The colority of the product obtained were up to 300. The method developed in this study provides a new approach for scale-up separation and purification of gardenia yellow from Gardenia jasminoides var. radicans Makino.




Overcoming non-specific adsorption issues for AZD9164 in human urine samples: Consideration of bioanalytical and metabolite identification procedures

Publication year: 2012Source:Journal of Chromatography BSteve Silvester, Frank Zang A key challenge in the development of robust bioanalytical methods, for the determination of drug analyte in human urine samples, is the elimination of po…

Publication year: 2012
Source:Journal of Chromatography B

Steve Silvester, Frank Zang

A key challenge in the development of robust bioanalytical methods, for the determination of drug analyte in human urine samples, is the elimination of potential analyte losses as a result of non-specific adsorption to container surfaces in which the samples are collected, stored or processed. A common approach to address adsorption issues is to treat the urine samples with additives that serve to increase analyte solubility and/or minimize interaction with the container surfaces. A series of adsorption experiments were performed on human urine samples containing an adsorption-prone in-house development compound (AZD9164). A roller-mixing methodology was employed to maximize sample interaction with container surfaces and quantification of analyte was performed by LC-MS/MS following minimal sample preparation. In the absence of any urine additive, adsorptive losses averaged 35% but were highly variable between different lots of urine. In the presence of a range of additives, including the surfactants Tween 80, 3—[(3—cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) and sodium dodecylbenzenesulfonate (SDBS), analyte adsorption was shown to be eliminated. Of particular academic interest was the finding that adsorptive losses could also be reduced upon addition of phospholipid. The presence of additive generally had no marked impact on the analyte MS response but the use of an isotopically-labelled internal standard satisfactorily compensated for instances in which ion suppression was observed, e.g. in the presence of Tween 80. Since metabolite profiling/identification investigations are often performed on urine samples originating from early clinical pharmacology studies, the elution of selected additives was also monitored by MS. CHAPS, dimethylacetamide (DMA) and HP—β—cyclodextrin eluted as single chromatographic peaks in, or just after, the column void volume whilst polymeric Tween 80, and to a lesser extent SDBS, eluted over a wide retention time window. The potential of the latter surfactants to obscure the detection of unknown metabolites is significant and therefore their use in urine samples, upon which metabolite investigations are to be performed, is not recommended. Upon consideration of other factors such as additive cost and toxicity, CHAPS was selected for use in development of the validated assay.




Validation Of The Pcr-Dhplc Method For Rapid Identification Of Candida Glabrata Phylogenetically Related Species In Different Biological Matrices

Publication year: 2012Source:Journal of Chromatography BO. Telleria, G. Ezpeleta, O. Herrero, I. Miranda-Zapico, G. Quindós, R. Cisterna Since two new species phylogenetically related to Candida glabrata with slightly different pheno…

Publication year: 2012
Source:Journal of Chromatography B

O. Telleria, G. Ezpeleta, O. Herrero, I. Miranda-Zapico, G. Quindós, R. Cisterna

Since two new species phylogenetically related to Candida glabrata with slightly different phenotypes and antifungal susceptibility profiles have been described, it seems to be necessary from clinical point of view, to develop a rapid and accurate identification system in order to distinguish between these three fungal species. We studied the performance of Denaturing High Performance Liquid Chromatography (dHPLC) as a faster (less than 7min) and alternative novel technique for simultaneous analysis of Candida species in different biological matrices. The analyses show the good low limit of detection (LLOD) in all biological matrices studied (5.16–9.56 ng·μL−1, 4.14-4.70 ng·μL−1 and 3.99-4.66 ng·μL−1 for Candida bracarensis, Candida nivariensis and C. glabrata, respectively). 180 Candida isolates were analyzed in order to demonstrate the method suitability for screening analysis to identify C. glabrata and its cryptic species (C. bracarensis and C. nivariensis) in clinical routine.




Sensitive determination of isoprostanes in exhaled breath condensate samples with use of liquid chromatography–tandem mass spectrometry

Publication year: 2012Source:Journal of Chromatography BMonika Janicka, Paweł Kubica, Agata Kot-Wasik, Jacek Kot, Jacek Namieśnik Oxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of rea…

Publication year: 2012
Source:Journal of Chromatography B

Monika Janicka, Paweł Kubica, Agata Kot-Wasik, Jacek Kot, Jacek Namieśnik

Oxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of reactive oxygen species in the lungs are reflected by elevated concentrations of oxidative stress markers in the breath, airways, lung tissue and blood. The aim of this work was to develop a method for the fast measurement of F2-isoprostanes in exhaled breath condensate (EBC) samples using equipment which is nowadays available and routinely exploited in analytical laboratories, liquid chromatography coupled with tandem mass spectrometry. Because of the limited volume of an EBC sample and the very low concentrations of biomarkers, we chose lyophilization as the preconcentration technique. The diastereoisomers determined show similar fragmentation patterns, which is why complete chromatographic separation with excellent peak shapes was essential for accurate quantitation. Isoprostanes were separated using a narrow-bore Agilent Extend C-18 column in isocratic elution mode using acetonitrile/methanol and water with the addition of 0.01%(v/v) formic acid. The limits of determination and quantitation for the determination of four isoprostanes in samples of EBC ranged from 1 to 3pg/ml. The recoveries of all isoprostanes ranged from 96.7 to 101.7, with a relative standard deviation of <7%. The stability of the isoprostanes at different temperatures was measured as well.




Application of a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to the pharmacokinetics, tissue distribution and excretion studies of felotaxel (SHR110008) in tumor-bearing mice

Publication year: 2012Source:Journal of Chromatography B, Volumes 887–888Yi Ding, ChengTao Lu, Jing Yang, Xin Jin, Lin Yang, Chao Wang, ZongYing Ma, YanRong Zhu, LiKun Ding, YanYan Jia, AiDong Wen Felotaxel (SHR110008), current…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 887–888

Yi Ding, ChengTao Lu, Jing Yang, Xin Jin, Lin Yang, Chao Wang, ZongYing Ma, YanRong Zhu, LiKun Ding, YanYan Jia, AiDong Wen

Felotaxel (SHR110008), currently under clinical investigation in phase I trial, is a new effective taxane with greater anticancer activity and less toxicity than docetaxel. Pharmacokinetic studies in animal models are the important components in clinical development of this agent. In this study, a rapid and sensitive analytical method based on high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) has been developed for the determination of felotaxel in tumor-bearing mice plasma, urine, feces and tissues (brain, heart, liver, lung and kidney and tumor). For all matrices, sample preparation involved liquid–liquid extraction with ethyl acetate. Calibration curves (1/x 2 weighted) offered satisfactory linearity (r 2 0.995) within the test range. The lower limit of quantitation (LLOQ) for all matrices was 10ng/ml except that for mouse plasma and brain LLOQ was 1ng/ml. The accuracy and precision ranged from 86.1 to 107.2% and 1.1 to 9.2%, respectively. Recoveries (73.9–96.1%) and matrix effects (76.4–97.2%) were satisfactory in all the biological matrices examined. Stability studies (85.1–101.5%) showed that felotaxel was stable both during the assay procedure and long-term storage. The assay was successfully applied to plasma pharmacokinetics, tissue distribution and excretion study of mice. The pharmacokinetic parameters, such as half-life, mean residence time, maximum concentration were determined. The preclinical data are useful for the design of clinical trials of felotaxel.




Separation and Purification of Phosvitin Phosphopeptides Using Immobilized Metal Affinity Nanoparticles

Publication year: 2012Source:Journal of Chromatography BJing Zhang, Jun Sun, Yuntao Liu, Junhua Li, Yujie Su, Wenshui Xia, Yanjun Yang Monodispersed and functional Immobilized Metal Affinity Magnetic chondroitin sodium sulfate nanopa…

Publication year: 2012
Source:Journal of Chromatography B

Jing Zhang, Jun Sun, Yuntao Liu, Junhua Li, Yujie Su, Wenshui Xia, Yanjun Yang

Monodispersed and functional Immobilized Metal Affinity Magnetic chondroitin sodium sulfate nanoparticles (short as IMAN @ Fe (III)) were prepared and employed in extracting of Phosvitin Phosphopeptides (short as PPPs) from egg yolk. It was found that the diameter of the magnetic CS nanoparticles was about 20nm, and they could easily be aggregated by a magnet when suspending in the aqueous solution. The adsorption equilibrium of PPPs onto the obtained nanocarriers fitted well with the Langmuir model. The adsorption capacity of PPPs onto the superparamagnetic nanoparticles was influenced by pH and the initial concentration of the peptides solution. The final nitrogen/phosphorus molar ratios (short as N/P) of PPPs from crude egg yolk peptides and phosvitin peptides were low to 5.78 and 5.23, respectively. Compared with traditional methods, the need for preparation of phosvitin before purification is obviated and the higher purity of PPPs were obtained. In conclusion, this type of IMAN @ Fe (III) would bring advantages to the conventional separation techniques of PPPs from chicken egg yolk.




Quantification of melamine in human urine using cation-exchange based high performance liquid chromatography tandem mass spectrometry

Publication year: 2012Source:Journal of Chromatography B, Volumes 887–888Parinya Panuwet, Johnny V. Nguyen, Erin L. Wade, Priya E. D’Souza, P. Barry Ryan, Dana Boyd Barr Melamine and cyanuric acid have been implicated as adulterants…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 887–888

Parinya Panuwet, Johnny V. Nguyen, Erin L. Wade, Priya E. D'Souza, P. Barry Ryan, Dana Boyd Barr

Melamine and cyanuric acid have been implicated as adulterants in baby formula in China and pet foods in North America. In China, the effect of melamine or melamine–cyanuric acid adulteration lead to kidney stone development and acute renal failure in thousands of Chinese infants. A selective and sensitive analytical method was developed to measure melamine in human urine in order to evaluate the extent of potential health implications resulting from the consumption of these types of adulterated products in the general US population. This method involves extracting melamine from human urine using cation-exchange solid-phase extraction, chromatographically separating it from its urinary matrix co-extractants on a silica-based, strong-cation exchange analytical column using high performance liquid chromatography, and analysis using positive mode electrospray ionization tandem mass spectrometry. Quantification was performed using modified, matrix-based isotope dilution calibration covering the concentration range of 0.50–100ng/mL. The limit of detection, calculated using replicates of blank and low level spiked samples, was 0.66ng/mL and the relative standard deviations were between 6.89 and 14.9%. The relative recovery of melamine was 101–106%. This method was tested for viability by analyzing samples collected from the general US population. Melamine was detected in 76% of the samples tested, with a geometric mean of 2.37ng/mL, indicating that this method is suitable for reliably detecting background exposures to melamine or other chemicals from which it can be derived.




PEGylation, detection and chromatographic purification of site-specific PEGylated CD133-Biotin antibody in route to stem cell separation

Publication year: 2012Source:Journal of Chromatography BMirna González-González, Karla Mayolo-Deloisa, Marco Rito-Palomares Recovery and purification of stem cells are determining steps in order to obtain the purity and viability requi…

Publication year: 2012
Source:Journal of Chromatography B

Mirna González-González, Karla Mayolo-Deloisa, Marco Rito-Palomares

Recovery and purification of stem cells are determining steps in order to obtain the purity and viability required for transplantation. In this context, immunochemical techniques have been widely preferred due to their high selectivity. CD133, a glycoprotein expressed by stem cells, is a well-used marker for isolation of neural stem cells. Transplantation of neural stem cells into patients can promote neural growth and improve neuronal functions. In this study, a new method for site-specific PEGylation of CD133-Biotin antibody is performed through streptavidin-biotin conjugation. Purification was carried out by ion-exchange chromatography. The characterization of the single PEGylated CD133-Biotin antibody was confirmed using electrophoresis with silver staining and I2-BaCl2 for PEG detection. Moreover, online PEG quantification directly after the chromatographic step was conducted (in each fraction) to detect exact elution times of PEG. In conclusion, the novel CD133-Biotin antibody PEGylation strategy conducted in this study could be used as a process step in route to neural stem cell recovery and purification via the modification of existing techniques such as aqueous two phase systems, PEGylated affinity columns or fluidized chromatography.




On-line continuous sampling dynamic microwave-assisted extraction coupled with high performance liquid chromatographic separation for the determination of lignans in Wuweizi and naphthoquinones in Zicao

Publication year: 2012Source:Journal of Chromatography B, Volumes 887–888Shiqian Gao, Jingyan You, Ying Wang, Rui Zhang, Hanqi Zhang The on-line continuous sampling dynamic microwave-assisted extraction (on-line CSDMAE) coupled with …

Publication year: 2012
Source:Journal of Chromatography B, Volumes 887–888

Shiqian Gao, Jingyan You, Ying Wang, Rui Zhang, Hanqi Zhang

The on-line continuous sampling dynamic microwave-assisted extraction (on-line CSDMAE) coupled with high-performance liquid chromatographic separation and determination of the lignans in Wuweizi and naphthoquinones in Zicao was developed. The extraction, separation and determination of target analytes were simultaneously carried out. The experimental parameters, including type of extraction solvent, microwave extraction power, solvent flow rate, amount of sample and particle size of the sample, were evaluated by the univariate method and orthogonal screening. The detection limits for schisandrin A, schisantherin A, deoxyschizandrin, shikonin and β,β′-dimethylacrylshikonin are 0.86, 0.90, 0.27, 0.42 and 0.92μgmL−1, respectively. Compared with the conventional extraction methods, such as off-line continuous microwave-assisted extraction, ultrasound-assisted extraction and Soxhlet extraction, the proposed method is quicker and more effective.




Analysis of Fatty Acid Composition in Insulin Secreting Cells by Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry

Publication year: 2012Source:Journal of Chromatography BAmy L. Payeur, Matthew A. Lorenz, Robert T. Kennedy A comprehensive two-dimensional gas chromatography (GC×GC) time-of-flight mass spectrometry method was developed for determinati…

Publication year: 2012
Source:Journal of Chromatography B

Amy L. Payeur, Matthew A. Lorenz, Robert T. Kennedy

A comprehensive two-dimensional gas chromatography (GC×GC) time-of-flight mass spectrometry method was developed for determination of fatty acids (irrespective of origin i.e., both free fatty acids and fatty acids bound in sources such as triglycerides) in cultured mammalian cells. The method was applied to INS-1 cells, an insulin-secreting cell line commonly used as a model in diabetes studies. In the method, lipids were extracted and transformed to fatty acid methyl esters for analysis. GC×GC analysis revealed the presence of 30 identifiable fatty acids in the extract. This result doubles the number of fatty acids previously identified in these cells. The method yielded linear calibrations and an average relative standard deviation of 8.4% for replicate injections of samples and 12.4% for replicate analysis of different samples. The method was used to demonstrate changes in fatty acid content as a function of glucose concentration on the cells. These results demonstrate the utility of this method for analysis of fatty acids in mammalian cell cultures.




Determination of 20(S)-protopanaxadiol ocotillol type epimers in rat plasma by liquid chromatography tandem mass spectrometry

Publication year: 2012Source:Journal of Chromatography B, Volumes 887–888Wenyan Wang, Yufeng Shao, Shasha Ma, Xiangmeng Wu, Qingguo Meng To study stereoselectivity in the pharmacokinetics of each epimer, a rapid, specific and reliabl…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 887–888

Wenyan Wang, Yufeng Shao, Shasha Ma, Xiangmeng Wu, Qingguo Meng

To study stereoselectivity in the pharmacokinetics of each epimer, a rapid, specific and reliable liquid chromatography tandem mass spectrometry method has been established for simultaneous quantitation of both epimers in rat plasma. Plasma samples were pretreated by liquid-liquid extraction. Chromatographic separations were performed on a Shim-pack XR-ODS C18 column (50mm×2.1mm, i.d., 2.2μm) with an isocratic elution. Both epimers and the internal standard tanshinone II A were ionized with an ESI source operated in positive ion mode and measured by selective reactions monitoring mode. Calibration curve was linear over the concentration range of 1–1000ng/mL with the lower limit of quantitation of 1ng/mL for both epimers. Intra and inter-day precisions were less than 6.7% and 9.5%, and the accuracy was within ±5.8% for both epimers. The validated method has been successfully applied to a pharmacokinetic study of the two epimers in rats after oral administration.




Corrigendum to: “Determination of picropodophyllin and its isomer podophyllotoxin in human serum samples with electrospray ionization of hexylamine adducts by liquid chromatography–tandem mass spectrometry” [J. Chromatogr. B 879 (5–6) (2011) 326–334]

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890Yuko Rönquist-Nii, Staffan Eksborg, Magnus Axelson, Johan Harmenberg, Simon Ekman, Michael Bergqvist, Olof Beck

Publication year: 2012
Source:Journal of Chromatography B, Volumes 889–890

Yuko Rönquist-Nii, Staffan Eksborg, Magnus Axelson, Johan Harmenberg, Simon Ekman, Michael Bergqvist, Olof Beck






Capillary ion electrophoresis of inorganic anions and uric acid in human saliva using a polyvinyl alcohol coated capillary column and hexamethonium chloride as additive of background electrolyte

Publication year: 2012Source:Journal of Chromatography B, Volumes 887–888Masanobu Mori, Tsukasa Yamamoto, Maki Kaseda, Sachiko Yamada, Hideyuki Itabashi A combination of polyvinyl alcohol chemically coated capillary (PVA capillary) a…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 887–888

Masanobu Mori, Tsukasa Yamamoto, Maki Kaseda, Sachiko Yamada, Hideyuki Itabashi

A combination of polyvinyl alcohol chemically coated capillary (PVA capillary) and background electrolyte (BGE) with ion-pair reagent (hexamethonium dichloride, HMC) was used on capillary ion electrophoresis-UV detection (CIE-UV) for analysis of Br, I, NO2 , NO3 , SCN and uric acid in human saliva. The PVA capillary prepared in our laboratory minimized electro-osmotic flow (EOF) at the BGE in pH 3–10, and did not affect the UV detection at 210nm by the PVA-layer on capillary wall. Therefore, use of the PVA capillary was suitable for sensitive UV detection for analyte anions, as well as suppression of protein adsorption. In this study, we optimized the BGE of 10mM phosphate plus 10mM HMC with applying a voltage of −15kV. HMC as an additive to BGE could manipulate the electrophoretic mobility of anions, without electrostatic adsorption to the PVA capillary. The CIE-UV could separate and determine analyte anions in human saliva containing proteins by the direct injection without pretreatments such as dilution or deproteinization within 13min. The relative standard deviations (n =10) were ranged of 0.5–1.6% in migration times, 2.2–6.8% in peak heights and 2.8–8.4% in peak areas. The limits of detection (S/N=3) were ranged of 3.42–6.87μM. The peak height of anions in this system was gradually decreased through the successive injections of saliva samples, but the problem was successfully solved by periodically conditioning the PVA capillary. The quantifiability of anions in human saliva samples by the CIE-UV was evaluated through the recoveries by standard addition methods and comparison of other representative analytical methods, as well as identification by ion chromatography (IC). From the anion analyses in 12 different saliva samples, the CIE-UV demonstrated that can obtain obvious differences in concentrations of SCN between of smoker and non-smoker and those of uric acid between male and female with satisfactory results.




Liquid chromatography–tandem mass spectrometric assay for the mutated BRAF inhibitor vemurafenib in human and mouse plasma

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890Rolf W. Sparidans, Selvi Durmus, Alfred H. Schinkel, Jan H.M. Schellens, Jos H. Beijnen A bioanalytical assay for the mutated BRAF inhibitor vemurafenib was dev…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 889–890

Rolf W. Sparidans, Selvi Durmus, Alfred H. Schinkel, Jan H.M. Schellens, Jos H. Beijnen

A bioanalytical assay for the mutated BRAF inhibitor vemurafenib was developed and validated. For the quantitative assay, human plasma samples were pre-treated using protein precipitation with water-acetonitrile (1/3, v/v) containing sorafenib as internal standard. The extract was directly injected into the chromatographic system. This system consisted of a sub-2μm particle, trifunctional bonded octadecyl silica column with isocratic elution using 0.01% (v/v) of formic acid in a mixture of water and methanol. The eluate was transferred into the electrospray interface with positive ionization and the analyte was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. The assay was validated in a 0.1–100μg/ml calibration range. Within day precisions were 1.6–3.2%, between day precisions 2.7% and 8.2% and accuracies were between 99% and 106% for the whole calibration range. The drug was stable under all relevant conditions. Finally, the assay was successfully used to assess drug levels in a pharmacokinetic mouse study.




Rapid and efficient purification of chrysophanol in Rheum Palmatum LINN by supercritical fluid extraction coupled with preparative liquid chromatography in tandem

Publication year: 2012Source:Journal of Chromatography BTiffany Chien-Ting Lo, Hung-Chi Nian, Kong-Hwa Chiu, Ai-Yih Wang, Ben-Zen Wu Chrysophanol has high pharmaceutical values. However, it was difficult to use the traditional extracti…

Publication year: 2012
Source:Journal of Chromatography B

Tiffany Chien-Ting Lo, Hung-Chi Nian, Kong-Hwa Chiu, Ai-Yih Wang, Ben-Zen Wu

Chrysophanol has high pharmaceutical values. However, it was difficult to use the traditional extraction method to extract high-concentration chrysophanol. Therefore, the purpose of this study is to purify and separate chrysophanol in traditional herb, Rheum Palmatum LINN, by using supercritical fluid extraction (SFE) and preparative high-performance liquid chromatography (P-HPLC) for rapid and large-scale isolation. The method is efficient for selective extraction of chrysophanol from the herbs, which have complex compositions. The extraction efficiency of chrysophanol with SFE is 25x higher than that of boiled water extraction under the same extraction time. The optimal conditions for SFE were 210 atm and 85°C for 30min; for P-HPLC, a C18 column was used with a gradient elution of methanol and 1% acetic acid at a flow rate of 10mL/min. According to 1H NMR and LC-MS analyses, the purity of the isolated chrysophanol was as high as 99%. The recovery for chrysophanol in Rheum after SPE/PHPLC processing was in the range of 88%–91.5%. Compared with other extraction and purification methods, the sequential system (SFE/P-HPLC) achieved the highest amount of extracted chrysophanol from Rheum Palmatum LINN (0.38mg/g) and the shortest run time (3h). Hence, this rapid and environmentally friendly method can separate compounds based on polarity with high efficiencies and, coupled with P-HPLC, it may be applicable in the large-scale production of foods and medicines in the future.




Comparison of three different C18 HPLC columns with different particle sizes for the optimization of aflatoxins analysis

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890A. Medina, N. Magan In this work we compared the performance of chromatography columns with particles of 5 and 3μm with the new 2.7μm solid core particles for th…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 889–890

A. Medina, N. Magan

In this work we compared the performance of chromatography columns with particles of 5 and 3μm with the new 2.7μm solid core particles for the analysis of aflatoxins B1, G1, B2, and G2 using trifluoroacetic acid pre-column derivatization. Three different columns have been used and chromatographic parameters as retention time, resolution, limit of detection (LOD), limit of quantification (LOQ) were obtained from all of them and compared. The results show that comparing with the traditional columns, shorter columns (100mm×4.6mm) with the new solid core particles are suitable for the analysis of these mycotoxins and allowed the reduction of the analysis time by 45.5% and 33.3% with respect to columns with particle size 5μm (150mm×4.6mm) and 3μm (150mm×4.6mm) respectively, without any detrimental effect on performance. This leads to the reduction of the analysis costs by saving on organic solvents and increasing the total number of analyses per day. The capability of these columns for analyzing samples, in different culture media, was assessed by analyzing different samples from: yeasts extract sucrose medium, corn meal agar medium and fresh hazelnut media.




LC/LC-MS/MS of an Innovative Prostate Human Epithelial Cancer (PHEC) in vitro Model System

Publication year: 2012Source:Journal of Chromatography BJohn D. Lapek, James L. McGrath, William A. Ricke, Alan E. Friedman This work describes the proteomic characterization of a novel in vitro prostate cancer model system, the clonal …

Publication year: 2012
Source:Journal of Chromatography B

John D. Lapek, James L. McGrath, William A. Ricke, Alan E. Friedman

This work describes the proteomic characterization of a novel in vitro prostate cancer model system, the clonal Prostatic Human Epithelial Cancer (PHEC) cell lines. The model is composed of three cell lines representing the three progressive cancer states found in vivo: non-tumorigenic, tumorigenic, and metastatic. The cell lines were evaluated for differential protein expression between states using two dimensional liquid:liquid chromatographic separation followed by mass spectral identification. The proteins from cellular extracts were first separated using liquid:liquid primary separation based on their isoelectric points and molecular masses. The resulting peptide fractions were applied to liquid chromatography mass spectrometry (LCMS) separation for mass determination and protein identification based on Mascot database inquiry. Over 200 proteins that change expression over the course of progression of this in vitro prostate cancer model were discovered during the comparative analysis of the three cell lines. The importance of these proteins on prostate cancer progression remains to be elucidated with further characterizations. The combination of the two dimensional liquid:liquid separation and mass spectral identifications was used to successfully analyze differential protein expression between multiple cell lines.




Regulatory control of glycopyrrolate in performance horses using validated UHPLC/MS–MS methods

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890M.J. Rumpler, R.A. Sams, P. Colahan We describe a validated, rapid, sensitive, and specific UHPLC–MS/MS method to detect and quantify glycopyrrolate in 0.5mL of…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 889–890

M.J. Rumpler, R.A. Sams, P. Colahan

We describe a validated, rapid, sensitive, and specific UHPLC–MS/MS method to detect and quantify glycopyrrolate in 0.5mL of horse urine. Further, we investigated the elimination of glycopyrrolate in urine after both intravenous and oral administration of clinically relevant doses to Thoroughbred horses. Quantification was performed by weighted, linear regression analysis using a deuterated analogue of glycopyrrolate as internal standard (IS). The method was characterized by a linear range of 5–2500pg/mL, a lower limit of quantification of 5pg/mL and a limit of detection of 1pg/mL. The intra and inter-batch imprecisions were <10% RSD and accuracy of the method ranged between 94 and 104%. Glycopyrrolate remained detectable in urine samples collected through 168h after intravenous administration and through 24h after oral administration. Analytical method validation requirements for linearity, specificity, precision, accuracy, stability, dilution integrity, matrix effect, and ruggedness have been fulfilled. The urine method described in this report is simple and efficient and is the first reported method with sufficient sensitivity, accuracy, and precision to regulate the use of glycopyrrolate in urine samples collected more than one day after dosing of horses. Urine to plasma glycopyrrolate concentration ratios were calculated and were approximately 100:1 in samples collected from 24h through the end of sample collection.




Sensitive quantification of roflumilast and roflumilast N-oxide in human plasma by LC-MS/MS employing parallel chromatography and electrospray ionization

Publication year: 2012Source:Journal of Chromatography BNorbert G. Knebel, Rolf Herzog, Felix Reutter, Karl Zech A high throughput bioanalytical method based on semi-automated liquid extraction and liquid chromatography-tandem mass spec…

Publication year: 2012
Source:Journal of Chromatography B

Norbert G. Knebel, Rolf Herzog, Felix Reutter, Karl Zech

A high throughput bioanalytical method based on semi-automated liquid extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS), has been developed for the sensitive quantification of roflumilast and its metabolite roflumilast N-oxide, a phosphodiesterase (PDE) inhibitor in human plasma and serum. The sample work-up procedure comprised liquid extraction using penta-deuterated analogues of both analytes as internal standards. Chromatography was performed on C18 revered phase analytical columns at a flow-rate of 0.5mL/min in the dual column mode employing a column switching technique and a linear gradient from 18% to 54% acetonitrile in 0.005M aqueous ammonium acetate containing 0.006% formic acid. Mass spectrometry was performed on an API 4000 instrument in the positive ion SRM-mode (selected reaction monitoring) with the Turbo-V® ionspray interface. The method showed linear detector responses over the entire calibration range between 0.1ng/mL (lower limit of quantification (LLOQ)) and 50ng/mL (upper limit of quantification (ULOQ)) for both analytes. Linear regression analysis with concentration-squared weighting (1/x2 for roflumilast and 1/x for roflumilast N-oxide) yielded inaccuracy and precision values<15% and coefficients of correlation (r) for the calibration curves>0.99 for both analytes.




Determination of antimalarial compound, ARB-89 (7β-hydroxy-artemisinin carbamate) in rat serum by UPLC/MS/MS and its application in pharmacokinetics

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890Deepthi Pabbisetty, Anuradha Illendula, K.M. Muraleedharan, Amar G. Chittiboyina, John S. Williamson, Mitchell A. Avery, Bonnie A. Avery Among all the antimal…

Publication year: 2012
Source:Journal of Chromatography B, Volumes 889–890

Deepthi Pabbisetty, Anuradha Illendula, K.M. Muraleedharan, Amar G. Chittiboyina, John S. Williamson, Mitchell A. Avery, Bonnie A. Avery

Among all the antimalarial agents, artemisinin and its semi synthetic family of analogs are the most potent antimalarials available for the treatment of Plasmodium falciparum infections. But these analogs have a few issues such as shorter half-lives and low oral bioavailability values. In order to overcome these inherent problems, novel artemisinin analogs were synthesized from 7β-hydroxy artemisinin by the Department of Medicinal Chemistry, University of Mississippi using a new synthesis mechanism. Out of all the 7β-hydroxy artemisinin analogs synthesized, 7β-hydroxy artemisinin carbamate (ARB-89) was chosen as a lead compound because of its high in vitro and in vivo activity. In this manuscript, a sensitive and rapid ultra-performance liquid chromatography tandem mass spectrometry (UPLC/MS/MS) method was developed and validated for the quantification of ARB-89 in rat serum. The analysis was carried out on an Acquity™ UPLC BEH C18 column (1.7μm, 2.1mm×50mm) with a flow rate of 0.3mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer in positive electrospray ionization (ESI) mode. The selected mass-to-charge (m/z) ratio transitions used in the multiple reaction monitoring (MRM) for ARB-89 and artemisinin (internal standard) were m/z 778.4>253.4 and m/z 283.4>151.1 respectively. The calibration curve was linear from 1.00ng/mL to 10.0μg/mL (r 2 =0.999). A simple protein precipitation method was used for extraction. Moreover, the inter-day and intra-day precision values were found to be less than 15%. The recoveries of the method ranged from 94.0% to 96.7% at three concentrations. ARB-89 in rat serum was found to be stable at room temperature for 12h. This method was successfully used to quantitate the novel antimalarial compound ARB-89 after intravenous and oral administration to rats.