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.




Development and validation of LC-MS/MS assays for the quantification of bendamustine and its metabolites in human plasma and urine

Publication year: 2012Source:Journal of Chromatography BA.C. Dubbelman, M. Tibben, H. Rosing, A. Gebretensae, L. Nan, S.H. Gorman, P. Robertson, J.H.M. Schellens, J.H. Beijnen A sensitive liquid chromatography tandem mass spectrome…

Publication year: 2012
Source:Journal of Chromatography B

A.C. Dubbelman, M. Tibben, H. Rosing, A. Gebretensae, L. Nan, S.H. Gorman, P. Robertson, J.H.M. Schellens, J.H. Beijnen

A sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay is described for the quantification of the anti-cancer agent bendamustine and its phase I metabolites γ-hydroxy-bendamustine (M3) and N-des-methylbendamustine (M4) and for its product of two-fold hydrolysis, dihydroxy-bendamustine (HP2), in human plasma and urine. Like most alkylating nitrogen mustards, bendamustine is prone to chemical hydrolysis in aqueous solution. To minimize degradation of bendamustine, urine samples were stabilized by a 100-fold dilution with human plasma and then processed identically to plasma samples. Sample aliquots of 200μL were mixed with an internal standard solution and acidified before separation of the analytes from the biomatrix with solid phase extraction. Dried and reconstituted extracts were injected on a Synergi Hydro RP column for the analysis of bendamustine, M3 and M4 or a Synergi Polar RP column for the analysis of HP2. Gradient elution was applied using 5mM ammonium formate with 0.1% formic acid in water and methanol as mobile phases. Analytes were ionized using an electrospray ionization source in positive mode and detected with a triple quadrupole mass spectrometer. The quantifiable range for bendamustine, M3 and M4 was 0.5 - 500ng/mL in plasma and 0.5 - 50μg/mL in urine, and that for HP2 was 1 - 500ng/mL in plasma and 0.1 - 50μg/mL in urine. The assays were accurate and precise, with inter-assay and intra-assay accuracies within±20% of nominal and CV values below 20% at the lower limit of quantification and within±15% of nominal and below 15% at the other concentration levels tested. These methods were successfully applied to evaluate the pharmacokinetic profile of bendamustine and its metabolites in cancer patients treated with bendamustine.




Determination of biomarkers of tobacco smoke exposure in oral fluid using solid-phase extraction and gas chromatography–tandem mass spectrometry

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890B.M. da Fonseca, I.E.D. Moreno, A.R. Magalhães, M. Barroso, J.A. Queiroz, S. Ravara, J. Calheiros, E. Gallardo A new, simple and sensitive method was descri…

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

B.M. da Fonseca, I.E.D. Moreno, A.R. Magalhães, M. Barroso, J.A. Queiroz, S. Ravara, J. Calheiros, E. Gallardo

A new, simple and sensitive method was described for the simultaneous determination of nicotine, cotinine and trans-3′-hydroxycotinine in oral fluid samples using solid-phase extraction and gas chromatography/tandem mass spectrometry (GC–MS/MS). This technique was developed using only 0.2mL of sample, and deuterated analogues were used as internal standards. The method was found to be linear between 0.5 and 1000ng/mL, with determination coefficients higher than 0.996 for all analytes. Intra- and interday precision and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. All analytes were stable in the samples for at least 24h at room temperature, for at least 72h at 25°C in processed samples and for at least three freeze/thaw cycles. Absolute recoveries ranged from 89 to 92% for all analytes. GC–MS/MS has demonstrated to be a powerful tool for the simultaneous quantitation of the analytes, providing adequate selectivity and sensitivity. In addition, its performance characteristics allow its routine use in the analysis of biomarkers of tobacco smoke exposure, extending the window of analyte detection in nicotine cessation programs, using a sample amount as low as 0.2mL of human oral fluid.




Development of a Fast and Simple Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantitation of Argatroban in Patient Plasma Samples

Publication year: 2012Source:Journal of Chromatography BJeanne M. Rhea, Marion L. Snyder, Anne M. Winkler, Charbel Abou-Diwan, Corinne R. Fantz, James C. Ritchie, Fania Szlam, Kenichi A. Tanaka, Ross J. Molinaro An ultra performanc…

Publication year: 2012
Source:Journal of Chromatography B

Jeanne M. Rhea, Marion L. Snyder, Anne M. Winkler, Charbel Abou-Diwan, Corinne R. Fantz, James C. Ritchie, Fania Szlam, Kenichi A. Tanaka, Ross J. Molinaro

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the direct measurement of argatroban in human plasma was developed and compared with the activity-based Hemoclot Thrombin Inhibitors assay. UPLC-MS/MS was performed using diclofenac as an internal standard. In summary, argatroban and diclofenac were extracted from a 100μL of plasma using a methanol precipitation protocol, and chromatographic separation was performed on an ACQUITY™ TQD mass spectrometer using a UPLC C18 BEH 1.7μm column with a water and methanol gradient containing 0.1% formic acid. The detection and quantitation were performed using positive ion electrospray ionization and multiple reaction monitoring (MRM) mode. The UPLC-MS/MS method was linear over the concentration range of 0.003-3.0μg/mL, with a lower limit of quantitation for argatroban of 0.003μg/mL. The intra- and inter-assay imprecision was less than 12% at the plasma argatroban concentrations tested. Good correlation was demonstrated between the UPLC-MS/MS method and the indirect activity-based assay for determination of argatroban. However, increased plasma fibrinogen levels caused underestimation of argatroban levels using the indirect activity-based assay, whereas the UPLC-MS/MS method was unaffected. UPLC-MS/MS provides a relatively simple, sensitive, and rapid means of argatroban monitoring. It has successfully been applied to assess plasma argatroban concentrations in hospitalized patients and may provide a more accurate determination of argatroban concentrations than an activity-based assay in certain clinical conditions.




A sensitive HPLC-based method to quantify adenine nucleotides in primary astrocyte cell cultures

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890Dhaval P. Bhatt, Xuesong Chen, Jonathan D. Geiger, Thad A. Rosenberger In mono-layered primary cell cultures baseline AMP and ADP levels are found nominally in t…

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

Dhaval P. Bhatt, Xuesong Chen, Jonathan D. Geiger, Thad A. Rosenberger

In mono-layered primary cell cultures baseline AMP and ADP levels are found nominally in the mid to low picomolar range and are thus difficult to measure with conventional HPLC methods that often require the pooling of samples or require indirect detection methods using radiotracers or enzyme coupled assays. To address this issue, we developed a highly sensitive and selective ion-pairing HPLC method with fluorescence detection to quantify adenine nucleotides and the adenylate energy charge in primary astrocyte cell cultures. To accomplish this, we optimized the fluorescence derivatization conditions and the HPLC parameters to achieve baseline separation and quantification of all adenine nucleotides. Nucleotides were converted to their respective 1, N6-etheno derivatives by incubating with chloroacetaldehyde at pH 4.5 and 60°C for 60min. Under these conditions, the loss of the adenine nucleotides due to hydrolysis was minimized with a derivatization yield of 94.1% for 1, N6-ethenoadenosine. The optimal concentration of tetrabutylammonium phosphate, the ion-pairing reagent, required to achieve a reproducible separation of the adenine nucleotides was found to be 0.8mM. Calibration curves of nucleotide standards were linear within the range of 0.16–10.4pmol for adenosine, 0.16–20.6pmol for AMP, 0.15–19.2pmol for ADP, and 0.15–19.5pmol for ATP. The limits of detection and quantification for all adenine nucleotides were approximately 0.08 and 0.16pmol, respectively. The intra- and inter-day variability for this method was less than 5.1 and 3.4%, respectively. This method was successfully used to measure all adenine nucleotides and an adenylate energy charge of 0.92±0.02 in primary astrocyte cell cultures.




Selective derivatization of nucleotide diphosphate (NDP)-4-keto sugars for electrospray ionization-mass spectrometry (ESI-MS)

Publication year: 2012Source:Journal of Chromatography BYun-Gon Kim, Hyung-Yeon Park, Dongwon Yoo, Changmin Sung, Eunjung Song, Jae-Hun Lee, Yun-Hui Choi, Yong-Hyun Kim, Chang-Soo Lee, Kyung-Moon Park, Byung-Gee Kim, Yung-Hun Ya…

Publication year: 2012
Source:Journal of Chromatography B

Yun-Gon Kim, Hyung-Yeon Park, Dongwon Yoo, Changmin Sung, Eunjung Song, Jae-Hun Lee, Yun-Hui Choi, Yong-Hyun Kim, Chang-Soo Lee, Kyung-Moon Park, Byung-Gee Kim, Yung-Hun Yang

Nucleotide diphosphate (NDP) sugars are widely present in antibiotics and glycoconjugates, such as protein- and lipid-linked oligosaccharides, where they act as substrates for glycosyltransferase in eukaryotes and prokaryotes. Among NDP sugars, NDP-4-keto sugars are key intermediates in the synthesis of structurally diverse NDP sugars with different functional groups. However, the structural identification of the NDP-4-keto sugars via mass spectrometry (electrospray ionization-mass spectrometry (ESI-MS)) continues to be a challenge because of the carbonyl group in these sugars interferes with ionization process. In this study, we evaluated various hydroxylamine compounds for the derivatization of NDP-4-keto sugars, so that the detection of the sugars by ESI-MS is more efficient. As a result, O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine was found to be the most effective tagging molecule for the detection of NDP-4-keto sugars without being interfered by original MS. This method can be used for identifying NDP-4-keto sugars such as thymidine diphosphate (TDP)-, adenosine diphosphate (ADP)-, uridine diphosphate (UDP)-, and cytosine diphosphate (CDP)-4-keto sugars as well as new NDP-4-keto-dehydratases.




Quantitation of bentysrepinine (Y101) in rat plasma by liquid chromatography tandem mass spectrometry: Application to pharmacokinetic study

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890Huirong Fan, Ruixing Li, Yuan Gu, Duanyun Si, Changxiao Liu A simple, accurate and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) method …

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

Huirong Fan, Ruixing Li, Yuan Gu, Duanyun Si, Changxiao Liu

A simple, accurate and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed and validated for quantitation of bentysrepinine (Y101) in rat plasma. After the addition of diphenhydramine (internal standard, IS), plasma samples were pretreated by protein precipitation. Chromatographic separation was carried out on an Atlantis® analytical column (4.6mm×100mm, 5μm, Waters) with methanol: 20mM ammonium formate consisting of 1.0% formic acid (65:35, v/v) as the mobile phase at an isocratic flow rate of 0.4mL/min for 7.5min. The multiple reaction monitoring (MRM) transitions were performed at m/z 490.2339.5 for Y101and m/z 256.0167.0 for IS on a SCIEX API 4000 mass spectrometer in the positive ion mode with electrospray ionization (ESI) source. Good linearity was achieved over the concentration range of 1–2500ng/mL. The intra- and inter-day precisions were less than 8.3%, and the accuracy ranged from −4.0% to 2.8%. Y101 was stable during the analysis and the storage period. The pharmacokinetic profiles of Y101 at three dose levels were successfully studied for the first time in rats by this method. After single intra-gastric administration of Y101 at the doses of 25, 50 and 100mg/kg, C max and AUC0–t were proportional to the doses given.




Corrigendum to: “Development and validation of a rapid and sensitive liquid chromatography–tandem mass spectrometry method for benvitimod quantification in human plasma” [J. Chromatogr. B 885–886 (2012) 160–165]

Publication year: 2012Source:Journal of Chromatography BLibo Zhao, Baoying Zhu, Xin Chen, Genghui Chen, Haibo Chen, Yuzhen Li, Shan Jing, Yi Fang

Publication year: 2012
Source:Journal of Chromatography B

Libo Zhao, Baoying Zhu, Xin Chen, Genghui Chen, Haibo Chen, Yuzhen Li, Shan Jing, Yi Fang






Molecular imprinting based composite cryogel membranes for purification of anti-hepatitis B surface antibody by fast protein liquid chromatography

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890Sevgi Asliyuce, Lokman Uzun, Abbas Yousefi Rad, Serhat Unal, Ridvan Say, Adil Denizli In the present study, we have focused our attention to prepare molecular …

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

Sevgi Asliyuce, Lokman Uzun, Abbas Yousefi Rad, Serhat Unal, Ridvan Say, Adil Denizli

In the present study, we have focused our attention to prepare molecular imprinted composite cryogel membranes for purification of hepatitis B surface antibody (anti-HBs) by fast protein liquid chromatography. Before the preparation of the molecular imprinted composite cryogel membranes (MI-CMs) by free radical polymerization at sub-zero temperature, we have synthesized and characterized the anti-HBs imprinted particles. Then, the cryogel membranes (CMs) were characterized by swelling test, scanning electron microscopy and Fourier transform infrared spectroscopy. Prior to chromatographic purification studies, the effective parameters on the anti-HBs adsorption process were evaluated by investigating the dependency of the adsorption capacity on flow-rate, anti-HBs concentration, contact time and ionic strength. The maximum anti-HBs adsorption capacity was calculated as 701.4mIU/g CM. The selectivity of the MI-CMs was shown by competitive adsorption of anti-HBs, total anti-hepatitis A antibody (anti-HAV) and total immunoglobulin E (IgE) adsorption studies. The MI-CMs have relative selectivity coefficients as 5.45 for anti-HBs/total anti-HAV and 9.05 for anti-HBs/total IgE, respectively. The phosphate buffer solution (pH 7.4) containing 1.0M NaCl was used for elution, almost completely, of adsorbed anti-HBs molecules. The MI-CMs could be used many times without any significant decrease in the adsorption capacity. The chromatographic purification performances of the MI-CMs were also investigated. The chromatographic parameters such as capacity and separation factors, the theoretical plate number and resolution of the MI-CMs were calculated as 5.48, 6.02, 1153.9, and 1.72 for anti-HBs molecules, respectively. As a conclusion, we can say that the MI-CMs could be used for specific purification of anti-HBs from anti-HBs positive human plasma.

Graphical Abstract

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Graphical abstract Highlights

► Molecular imprinted cryogel membranes (MI-CMs) for anti-HBs purification by FPLC. ► The MI-CMs: a novel candidate for specific anti-HBs purification from human plasma. ► Competitive adsorption of anti-HBs, total anti-HAV and total IgE were carried out. ► The MI-CMs can be used many times without any significant decrease in the capacity. ► The chromatographic purification performances of the MI-CMs were evaluated.



Liquid chromatography-electrospray quadrupole linear ion trap mass spectrometry method for the quantitation of palonosetron in human plasma and urine: application to a pharmacokinetic study

Publication year: 2012Source:Journal of Chromatography BPengfei Li, Ping Ma, Yan Wang, Weihang Tong, Jing Wang, Cheng Wu, Lihong Liu The new analytical method for the determination of palonosetron in human plasma and urine has been d…

Publication year: 2012
Source:Journal of Chromatography B

Pengfei Li, Ping Ma, Yan Wang, Weihang Tong, Jing Wang, Cheng Wu, Lihong Liu

The new analytical method for the determination of palonosetron in human plasma and urine has been developed based on liquid chromatography mass spectrometry. The method utilized Tramadol as the internal standard (IS). Separation was carried out on a Zorbax Eclipse TC-C18 column using methanol-1mM ammonium formate in water (containing 0.1% formic acid, v/v, pH=2.8) as mobile phase for gradient elution. Detection is carried out by multiple reaction monitoring (MRM) on 3200Qtrap™ mass spectrometry. The method has a chromatographic run time of 5.5min and is linear within the concentration range 0.01–5.00ng/mL for plasma and 0.10–30.00ng/mL for urine both with a LOD of 0.003ng/mL. Intra- and inter-day RSD of the concentration were 3.66%-6.60%, 1.29%-7.71% for plasma and 2.39%-5.76%, 2.06%-7.13% for urine. The relative error (RE) were -4.58%–3.26% for plasma and -1.47%–2.53% for urine. The recovery rates of palonosetron and IS both for plasma and urine were more than 90%. Palonosetron was stable under all the conditions tested. The method was successfully used to analyze palonosetron in human plasma and urine over a period of 168h after intravenously pumping a single dose of 0.25mg to volunteers. No significant differences were found between the pharmacokinetic parameters and urine accumulated excretory rate for male and female volunteers (P>0.05). A two-compartment model was obtained after administrations. Palonosetron was eliminated at a slow rate in volunteers. The mean urine accumulated excretory rate was 25.97±12.87%. Inter-individual differences could not be neglected due to the high coefficient of variety in several pharmacokinetic parameters and the urine accumulated excretion.




Evaluation of enantioselective binding of propanocaine to human serum albumin by ultrafiltration and electrokinetic chromatography under intermediate precision conditions

Publication year: 2012Source:Journal of Chromatography B, Volumes 889–890María Amparo Martínez-Gómez, Laura Escuder-Gilabert, Rosa María Villanueva-Camañas, Salvador Sagrado, María José Medina-Hernández Stereoselectivity in p…

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

María Amparo Martínez-Gómez, Laura Escuder-Gilabert, Rosa María Villanueva-Camañas, Salvador Sagrado, María José Medina-Hernández

Stereoselectivity in protein binding can have a significant effect on the pharmacokinetic and pharmacodynamic properties of chiral drugs. In this paper, the enantioselective binding of propanocaine (PRO) enantiomers to human serum albumin (HSA), the most relevant plasmatic protein in view of stereoselectivity, has been evaluated by incubation and ultrafiltration of racemic PRO–HSA mixtures and chiral analysis of the bound and unbound fractions by electrokinetic chromatography using HSA as chiral selector. Experimental conditions for the separation of PRO enantiomers using HSA as chiral selector and electrokinetic chromatography have been optimised. Affinity constants and protein binding in percentage (PB) were obtained for both enantiomers of PRO, as well as the enantioselectivity (ES) to HSA. Data were obtained in two independent working sessions (days). The influence of the session and fraction processed factors were examined. A univariate direct-estimation approach was used facilitating outliers’ identification and statistical comparison. Non-linear fitting of data was used to verify the stoichiometry and affinity estimations obtained by the direct approach. Robust statistics were applied to obtain reliable estimations of uncertainty, accounting for the factors (day and processed fraction), thus representing intermediate precision conditions. Mimicking in vivo experimental conditions, information unapproachable by in vivo experiments was obtained for PRO enantiomers interacting with HSA. For the first (E1) and the second (E2) eluted PRO enantiomers the results were: 1:1 stoichiometry, medium affinity constants, log K E1 =3.20±0.16 and log K E2 =3.40±0.14, medium protein binding percentage, PB=48.7 and 60.1% for E1 and E2, respectively, and moderate but significant enantioselectivity, ES= K E2/K E1 =1.5±0.3.




Screening and identification of BSA bound ligands from Puerariae lobata flower by BSA functionalized Fe3O4 magnetic nanoparticles coupled with HPLC–MS/MS

Publication year: 2012Source:Journal of Chromatography B, Volumes 887–888Liangliang Liu, Yongjian Ma, Xiaoqing Chen, Xiang Xiong, Shuyun Shi Puerariae lobata flower (Willdenow) has a long history used to treat alcoholic intoxication…

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

Liangliang Liu, Yongjian Ma, Xiaoqing Chen, Xiang Xiong, Shuyun Shi

Puerariae lobata flower (Willdenow) has a long history used to treat alcoholic intoxication in China, which contains a series of isoflavones as its chief pharmacologically active constituents. In this study, bovine serum albumin (BSA) functionalized iron oxide magnetic nanoparticles (Fe3O4 MNPs) coupled with high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) were used to screen and identify active compounds from ethanolic extract of P. lobata flower. Thirteen active isoflavones were screened and identified as glycitin (1), tectoridin (2), daidzin (3), 3′-methoxy daidzin (4), ononin (5), 3′-hydroxyl daidzein (6), tectorigenin (7), biochanin A (8), prunetin (9), genistein (10), 3′-methoxy daidzein (11), irisolidone (12) and 5,7-dihydroxy-3′,4′-methylenedioxyisoflavone (13), while compounds 4, 6, 9, 11 and 13 were identified from this plant for the first time. Furthermore, the activity of each bound ligand was evaluated on-line. The results indicated that the binding affinities of compounds with BSA were highly dependent on chemical structures and the methoxylation and hydroxylation on B-ring could improve the activity. The effective method could be widely applied for rapid screening and identification of active compounds from complex mixtures.