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Ultra-performance Liquid Chromatography (ultra-performance + liquid_chromatography)
Selected AbstractsUltra-performance liquid chromatography coupled to linear ion trap mass spectrometry for the identification of drug metabolites in biological samplesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2006G. J. Dear The coupling of ultra-performance liquid chromatography, operating at elevated pressures, to a linear ion trap mass spectrometer provides a high-performance system suitable for drug metabolite characterisation. This system demonstrates improved chromatographic efficiency and sensitivity and at the same time provides diagnostic MSn data often critical for metabolite structural assignment. The linear ion trap was capable of dealing with the high chromatographic efficiencies and hence narrow peak widths associated with 1.7,µm particle-packed column separations. Polarity switching and data-dependent MSn data were generated with ease, and applied to the identification of metabolites found in human plasma. Copyright © 2006 John Wiley & Sons, Ltd. [source] Reduction of Acrylamide and Its Kinetics by Addition of Antioxidant of Bamboo Leaves (AOB) and Extract of Green Tea (EGT) in Asparagine,Glucose Microwave Heating SystemJOURNAL OF FOOD SCIENCE, Issue 2 2008Yu Zhang ABSTRACT:, This study investigated the effect of antioxidant of bamboo leaves (AOB) and extract of green tea (EGT) on the formation and kinetics of acrylamide in an equimolar asparagine,glucose model system. The substrates spiked with AOB and EGT were microwave-heated at 180 °C and the acrylamide content in final reaction products was quantified by ultra-performance liquid chromatography,tandem mass spectrometry (UPLC-MS/MS). The results showed that both AOB and EGT could effectively reduce the formation of acrylamide in an asparagine,glucose microwave heating model system and achieved a maximum reduction rate when the addition levels of AOB and EGT were both 10,6 mg/mL reaction solution. To describe the kinetic behavior of acrylamide, a simplified kinetic model was optimized and relative kinetic rate constants were evaluated under isothermal conditions. The results indicated that the reduction effect of AOB and EGT on the acrylamide formation may partly be ascribed to the decrease of the formation rate constant (kF) in both AOB and EGT-spiked systems (43.4% and 32.3% of decrease, respectively, P < 0.05). The kinetic parameter kE, which represents the elimination rate of acrylamide in both AOB and EGT-spiked systems, was not significantly different (6.9% of increase and 10.9% of decrease, respectively, P > 0.05). The results of the kinetic study indicated that addition of AOB and EGT could significantly reduce the formation rate constant (kF) of acrylamide, but could not significantly affect the elimination rate constant (kE) of acrylamide. [source] Determination of multicomponent contents in Calculus bovis by ultra-performance liquid chromatography,evaporative light scattering detection and its application for quality controlJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2010Weijun Kong Abstract A fast ultra-performance liquid chromatography,evaporative light scattering detection (UPLC-ELSD) method was established for simultaneous quantification of seven components in natural Calculus bovis (C. bovis) and its substitutes or spurious breeds. On a Waters Acquity UPLC® BEH C18 column, seven analytes were efficiently separated using 0.2% aqueous formic acid,acetonitrile as the mobile phase in a gradient program. The evaporator tube temperature of ELSD was set at 100°C with the nebulizing gas flow-rate of 1.9,L/min. The results showed that this established UPLC-ELSD method was validated to be sensitive, precise and accurate with the LODs of seven analytes at 2,11,ng, and the overall intra-day and inter-day variations less than 3.0%. The recovery of the method was in the range of 97.8,101.6%, with RSD less than 3.0%. Further results of PCA on the contents of seven investigated analytes suggested that compounds of cholic acid, deoxycholic acid and chenodeoxycholic acid or cholesterol should be added as chemical markers to UPLC analysis of C. bovis samples for quality control and to discriminate natural C. bovis sample and its substitutes or some spurious breeds, then normalize the use of natural C. bovis and ensure its clinical efficacy. [source] A rapid ultra-performance liquid chromatography,electrospray Ionisation mass spectrometric method for the analysis of saponins in the adventitious roots of Panax notoginsengPHYTOCHEMICAL ANALYSIS, Issue 1 2009Mo Dan Abstract Introduction Saponins are bioactive compounds employed in the prevention and treatment of cardiovascular and cerebrovascular diseases. The adventitious roots of Panax notoginseng may offer an alternative source of saponins. Identification and determination of saponins in the crude extract is challenging owing to their similar structures and the lack of standards. Objective To develop a rapid, sensitive and accurate method based on solid-phase extraction followed by ultra-performance liquid chromatography,electrospray ionisation mass spectrometry (UPLC-ESI-MS) for the identification and quantification of saponins in P. notoginseng. Methodology Following extraction using Waters OasisTM HLB cartridges, the analytes were subjected to a UPLC system with a Waters Acquity BEH C18 chromatographic column and a binary mobile phase system consisting of 0.05% formic acid in water and acetonitrile under gradient elution conditions, with final detection by ESI-MS in the positive ion mode. Results The UPLC-ESI-MS method gave limits of detection and quantification within the range 0.015,0.382 and 0.052,1.124 µg/mL, respectively, for 15 studied saponins. The instrumentation/injection precision (RSD) was 4.5% for a low concentration and 3.2% for an intermediate concentration sample. The intra- and inter-day repeatability was less than 2.65% (RSD). The method described was validated using spiked samples with different amounts of saponin standards. Conclusion This UPLC-ESI-MS assay provides a suitable quality control method for the tentative identification and determination of major biological active constituents in adventitious and native roots of P. notoginseng. Copyright © 2008 John Wiley & Sons, Ltd. [source] Biochemical and analytical development of the CIME cocktail for drug fate assessment in humansRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 16 2010Orianne Videau Phenotyping based on drug metabolism activity appears to be informative regarding mechanism-based interactions during drug development. We report here the first steps of the development of the innovative CIME cocktail. This cocktail is designed not only for the major cytochrome P450, with caffeine, amodiaquine, tolbutamide, omeprazole, dextromethorphan and midazolam as substrates of CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A, respectively, but also phase II enzymes UGT 1A1/6/9 with acetaminophen, P-gp and OATP1B1 with digoxin and rosuvastatin, and renal function with memantine. An assay combining ultra-performance liquid chromatography using a 1.7,µm particle size column with tandem mass spectrometry (UPLC/MS/MS) was set up for the simultaneous quantification of the 20 substrates and metabolites after extraction from human plasma using solid-phase extraction. The method was validated in the spirit of the FDA guidelines. Mean accuracy ranged from 87.7 to 115%, the coefficient of variance (CV%) of intra- and inter-run from 1.7 to 16.4% and from 1.6 to 14.9%, respectively, and for the limit of quantification (LOQ) with ten lots of plasma, accuracy ranged from 84 to 115% and CV% precision was <16%. Short-term stability was evaluated in eluate (4,h, room temperature), plasma (24,h, room temperature), the autosampler (24,h, 4°C) and in three freeze/thaw cycles in plasma. All except three analytes were stable under these conditions. For the three others a specific process can be followed. This robust, fast and sensitive assay in human plasma provides an analytical tool for ten-probe drugs of the CIME cocktail. Clinical samples will be assayed in the near future using this new assay method. Copyright © 2010 John Wiley & Sons, Ltd. [source] Characterization of protostane triterpenoids in Alisma orientalis by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2010Xin Liu A reliable and sensitive ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method has been optimized and established for analysis of protostane triterpenoids in a commonly used traditional Chinese herbal medicine Alisma orientalis (Sam.) Juzep. The separation of crude extract of A. orientalis was achieved on a Waters ACQUITY HSS T3 column (100,mm,×,2.1,mm, 1.8,µm) eluting with 0.1% (v/v) formic acid/acetonitrile. A total of 20 protostane triterpenoids including 19 known compounds and a new one were well separated within 7,min. The collision-induced dissociation (CID) tandem mass spectrometric (MS/MS) fragmentation patterns of protostane triterpenoids was firstly reported in this study. The hydrogen rearrangement at the C-23-OH leads to dissociation of the bond between C-23 and C-24 in the protostane triterpenoid skeleton during the CID process. This dissociation was the characteristic CID fragmentation pathway of this class of triterpenoids, and was useful for further differentiation of some positional isomers which contain an acetyl unit on the C-23 or C-24 position. The identities of isolated compounds were identified by comparing their retention times and CID fragmentation behaviors with those of reference standards or tentatively assigned by matching the empirical molecular formulae with those reported in the literature. It is concluded that this newly established UPLC/Q-TOF-MS method is a powerful approach for structural elucidation of protostane triterpenoids isolated from A. orientalis. Copyright © 2010 John Wiley & Sons, Ltd. [source] Structural elucidation of metabolites of ginkgolic acid in rat liver microsomes by ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry and hydrogen/deuterium exchangeRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 13 2009Z. H. Liu Ginkgolic acids have been shown to possess allergenic as well as genotoxic and cytotoxic properties. The question arises whether the metabolism of ginkgolic acids in the liver could decrease or increase their toxicity. In this study, the invitro metabolism of ginkgolic acid (15:1, GA), one component of ginkgo acids, was investigated as a model compound in Sprague-Dawley rat liver microsomes. The metabolites were analyzed by ultra-performance liquid chromatography coupled with photodiode array detector/negative-ion electrospray ionization tandem mass spectrometry (UPLC-PDA/ESI-MS/MS) and hydrogen/deuterium (H/D) exchange. The result showed that the benzene ring remained unchanged and the oxidations occurred at the side alkyl chain in rat liver microsomes. At least eight metabolites were found. Among them, six phase I metabolites were tentatively identified. This study might be useful for the investigation of toxicological mechanism of ginkgolic acids. Copyright © 2009 John Wiley & Sons, Ltd. [source] False-positive liquid chromatography/tandem mass spectrometric confirmation of sebuthylazine residues using the identification points system according to EU directive 2002/657/EC due to a biogenic insecticide in tarragonRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2009Andreas Schürmann In pesticide residue analysis using liquid chromatography/tandem mass spectrometry (LC/MS/MS) the confirmation of a sebuthylazine finding in a tarragon (Artemisia dranunculus) sample was demonstrated to be false positive. A coeluting interfering matrix compound produced product ions in MS/MS analysis, perfectly corresponding to the multiple reaction monitoring (MRM) of two sebuthylazine transitions. Using the EU directive 2002/657/EC which regulates the confirmation of suspected positive findings would have resulted in a false-positive finding. A third LC/MS/MS transition with a deviant ion ratio and a gas chromatography (GC)/MS/MS analysis revealed the false-positive results. With optimized high resolving ultra-performance liquid chromatography (UPLC) conditions it was possible to separate spiked sebuthylazine from the interfering matrix compound. Using its exact mass and isotope ratios from LC/time-of-flight (TOF) MS measurements, the compound was identified as nepellitorine, a , not surprising , endogenous alkamide in tarragon (Arthemisia dranunculus). False-positive results, especially in heavy matrix samples such as herbs, can be dealt with by further confirmatory analysis, e.g. a third transition, GC analysis if possible or more advantageous by an orthogonal criterion like exact mass. Copyright © 2009 John Wiley & Sons, Ltd. [source] Ultra-performance liquid chromatography coupled to linear ion trap mass spectrometry for the identification of drug metabolites in biological samplesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2006G. J. Dear The coupling of ultra-performance liquid chromatography, operating at elevated pressures, to a linear ion trap mass spectrometer provides a high-performance system suitable for drug metabolite characterisation. This system demonstrates improved chromatographic efficiency and sensitivity and at the same time provides diagnostic MSn data often critical for metabolite structural assignment. The linear ion trap was capable of dealing with the high chromatographic efficiencies and hence narrow peak widths associated with 1.7,µm particle-packed column separations. Polarity switching and data-dependent MSn data were generated with ease, and applied to the identification of metabolites found in human plasma. Copyright © 2006 John Wiley & Sons, Ltd. [source] Increasing throughput and information content for in vitro drug metabolism experiments using ultra-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometerRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2005Jose Castro-Perez The field of drug metabolism has been revolutionized by liquid chromatography/mass spectrometry (LC/MS) applications with new technologies such as triple quadrupoles, ion traps and time-of-flight (ToF) instrumentation. Over the years, these developments have often relied on the improvements to the mass spectrometer hardware and software, which has allowed users to benefit from lower levels of detection and ease-of-use. One area in which the development pace has been slower is in high-performance liquid chromatography (HPLC). In the case of metabolite identification, where there are many challenges due to the complex nature of the biological matrices and the diversity of the metabolites produced, there is a need to obtain the most accurate data possible. Reactive or toxic metabolites need to be detected and identified as early as possible in the drug discovery process, in order to reduce the very costly attrition of compounds in late-phase development. High-resolution, exact mass measurement plays a very important role in metabolite identification because it allows the elimination of false positives and the determination of non-trivial metabolites in a much faster throughput environment than any other standard current methodology available to this field. By improving the chromatographic resolution, increased peak capacity can be achieved with a reduction in the number of co-eluting species leading to superior separations. The overall enhancement in the chromatographic resolution and peak capacity is transferred into a net reduction in ion suppression leading to an improvement in the MS sensitivity. To investigate this, a number of in vitro samples were analyzed using an ultra-performance liquid chromatography (UPLC) system, with columns packed with porous 1.7,,m particles, coupled to a hybrid quadrupole time-of-flight (ToF) mass spectrometer. This technique showed very clear examples for fundamental gains in sensitivity, chromatographic resolution and speed of analysis, which are all important factors for the demands of today's HTS in discovery. Copyright © 2005 John Wiley & Sons, Ltd. [source] A rapid assay for angiotensin-converting enzyme activity using ultra-performance liquid chromatography,mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Fang Geng Abstract Angiotensin-converting enzyme (ACE) plays an important role in the renin,angiotensin system and ACE activity is usually assayed in vitro by monitoring the transformation from a substrate to the product catalyzed by ACE. A rapid and sensitive analysis method or ACE activity by quantifying simultaneously the substrate hippuryl,histidyl,leucine and its product hippuric acid using an ultra-performance liquid chromatography coupled with electrospray ionization-mass spectrometry (UPLC-MS) was first developed and applied to assay the inhibitory activities against ACE of several natural phenolic compounds. The established UPLC-MS method showed obvious advantages over the conventional HPLC analysis in shortened running time (3.5,min), lower limit of detection (5,pg) and limit of quantification (18,pg), and high selectivity aided by MS detection in selected ion monitoring (SIM) mode. Among the six natural products screened, five compounds, caffeic acid, caffeoyl acetate, ferulic acid, chlorogenic acid and resveratrol indicated potent in vitro ACE inhibitory activity with IC50 values of 2.527 ± 0.032, 3.129 ± 0.016, 10.898 ± 0.430, 15.076 ± 1.211 and 6.359 ± 0.086,mm, respectively. A structure,activity relationship estimation suggested that the number and the situation of the hydroxyls on the benzene rings and the acrylic acid groups may play the most predominant role in their ACE inhibitory activity. Copyright © 2009 John Wiley & Sons, Ltd. [source] Simultaneous assay of sildenafil and desmethylsildenafil in neonatal plasma by ultra-performance liquid chromatography,tandem mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 2 2010Bregje C. Witjes Abstract Sildenafil is used to treat pulmonary hypertension in neonatal and pediatric patients. Pharmacokinetic studies in these patients are complicated by the limited sample volume. We present the validation results of an assay method to quantitate sildenafil and desmethylsildenafil simultaneously in 50,µL of plasma. Deuterated sildenafil was used as an internal standard. After liquid,liquid extraction, analytes were separated on an ultra-performance liquid chromatography (UPLC)-column and quantified via tandem mass spectrometry. The calibration range was linear, with acceptable accuracy and a precision of <15% for both compounds. The lower limits of quantification were 1,ng/mL. Matrix effects were present, but inter-plasma batch variability was under 12%. The method was successfully applied to samples from a pharmacokinetic study into sildenafil pharmacokinetics in neonates, making maximum use of the limited number and amount of plasma samples available. Copyright © 2009 John Wiley & Sons, Ltd. [source] Determination of a novel paclitaxel derivative (NPD-103) in human plasma by ultra-performance liquid chromatography,tandem mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 5 2009Shuang-Qing Zhang Abstract A sensitive and specific ultra-performance liquid chromatography,tandem mass spectrometry (UPLC-MS-MS) method for quantification of a newly developed anticancer agent NPD-103 has been established. An aliquot of human plasma sample (200 µL) was spiked with 13C-labeled paclitaxel (internal standard) and extracted with 1.3 mL of tert -butyl methyl ether. NPD-103 was quantitated on a C18 column with methanol,0.1% formic acid (75:25, v/v) as mobile phase using UPLC-MS-MS operating in positive electrospray ionization mode with a total run time of 3.0 min. For NPD-103 at the concentrations of 1.0, 5.0 and 10.0 µg/mL in human plasma, the absolute extraction recoveries were 95.58, 102.43 and 97.77%, respectively. The linear quantification range of the method was 0.1,20.0 µg/mL in human plasma with linear correlation coefficients greater than 0.999. The intra- and inter-day accuracy for NPD-103 at 1.0, 5.0 and 10.0 µg/mL levels in human plasma fell into the ranges of 95.29,100.00% and 91.04,94.21%, and the intra- and inter-day precisions were in the ranges of 8.96,11.79% and 7.25,10.63%, respectively. This assay is applied to determination of half-life of NPD-103 in human plasma. Copyright © 2008 John Wiley & Sons, Ltd. [source] Rapid analysis of N -linked oligosaccharides in glycoproteins (ovalbumin, ribonuclease B and fetuin) by reversed-phase ultra-performance liquid chromatography with fluorescence detection and electrospray ionization time-of-flight mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 5 2009Takamasa Kurihara Abstract Rapid, selective and sensitive determination of N -linked oligosaccharides in glycoproteins (ovalbumin, ribonuclease B and fetuin) was performed by ultra-performance liquid chromatography (UPLC) with fluorescence (FL) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). The asparaginyl-oligosaccharide moiety was first liberated from each glycoprotein by pronase E (a proteolitic enzyme). The oligosaccharide fractions separated by gel-permeation chromatography were labeled with 1-pyrenesulfonyl chloride (PSC, a fluorescence reagent), separated by UPLC in a short run time, and then detected by FL and TOF-MS. The PSC-labeled oligosaccharides were selectively identified from the FL detection and then sensitively determined by ESI-TOF-MS. As the results, 15, eight and four kinds of N -linked oligosaccharides were detected from ovalbumin, ribonuclease B and fetuin, respectively. Because the present method is rapid (within 9 min), selective and sensitive (approximate 60 fmol, S/N = 5), the determination of N -linked oligosaccharides in various glycoproteins seems to be possible. Copyright © 2008 John Wiley & Sons, Ltd. [source] Determination of a novel epothilone D analog (AV-EPO-106) in human plasma using ultra-performance liquid chromatography,tandem mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 3 2009Shuang-Qing Zhang Abstract A novel ultra-performance liquid chromatography,tandem mass spectrometry (UPLC-MS-MS) method has been established for the determination of a newly synthesized epothilone D analog (AV-EPO-106) in human plasma. The plasma samples were prepared by liquid,liquid extraction with cold tert -butyl methyl ether. The chromatographic separation was achieved within 5 min on a C18 column with water,methanol (10:90, v/v) as mobile phase at a flow-rate of 0.8 mL/min. Mass transition of m/z 568.2 to 386.1 was measured for AV-EPO-106 in positive atmospheric pressure chemical ionization mode. A detailed validation of the method was performed as per the USFDA guidelines. For AV-EPO-106 at the concentrations of 1.0, 5.0 and 10.0 µg/mL in human plasma, the absolute extraction recoveries were 86.17, 85.24 and 85.69%, respectively. The linear quantification range of the method was 0.10,20.0 µg/mL in human plasma with linear correlation coefficients greater than 0.999. The intra-day and inter-day accuracy for AV-EPO-106 at the levels of 1.0, 5.0 and 10.0 µg/mL in human plasma fell in the ranges of 98.25,100.47 and 94.19,97.25%, and the intra- and inter-day precision were in the ranges of 4.75,6.30% and 8.89,10.45%, respectively. The method was successfully applied to quantify AV-EPO-106 in human plasma to determine the half-life of this compound in human plasma. Copyright © 2008 John Wiley & Sons, Ltd. [source] Simultaneous determination of udenafil and its active metabolite, DA-8164, in human plasma and urine using ultra-performance liquid chromatography,tandem mass spectrometry: application to a pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 9 2008Soo Kyung Bae Abstract A rapid, sensitive, and simple ultra-performance liquid chromatography,tandem mass spectrometry (UPLC/MS/MS) method for the determination of udenafil and its active metabolite, DA-8164, in human plasma and urine using sildenafil as an internal standard (IS) was developed and validated. Udenafil, DA-8164 and IS from a 100 µL aliquot of biological samples were extracted by protein precipitation using acetonitrile. Chromatographic separation was carried on an Acquity UPLC BEH C18 column (50 × 2.1 mm, i.d., 1.7 µm) with an isocratic mobile phase consisting of acetonitrile and containing 0.1% formic acid (75:25, v/v) at flow rate of 0.4 mL/min, and total run time was within 1 min. Detection and quantification was performed by the mass spectrometer using multiple reaction-monitoring mode at m/z 517 , 283 for udenafil, m/z 406 , 364 for DA-8164 and m/z 475 , 100 for IS. The assay was linear over a concentration range of 1,600 ng/mL with a lower limit of quantification of 1 ng/mL in both human plasma and urine. The coefficient of variation of this assay precision was less than 13.7%, and the accuracy exceeded 92.0%. This method was successfully applied for pharmacokinetic study after oral administration of udenafil 100 mg to healthy Korean male volunteers. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||