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Tandem Mass Spectrometric Method (tandem + mass_spectrometric_method)

Distribution by Scientific Domains
Chemistry93%

Kinds of Tandem Mass Spectrometric Method

  • liquid tandem mass spectrometric method
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    Selected Abstracts

    Quantification of urinary N -acetyl- S - (propionamide)cysteine using an on-line clean-up system coupled with liquid chromatography/tandem mass spectrometry

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 4 2005
    Chien-Ming Li
    Abstract Acrylamide has been reported to be present in high-temperature processed foods and normal processed food intake could lead to significant acrylamide exposure. Acrylamide in vivo can be conjugated with glutathione in the presence of glutathione transferase. This conjugation product is further metabolized and excreted as N -acetyl- S -(propionamide)cysteine (NASPC) in the urine. NASPC could be considered a biomarker for acrylamide exposure. The objective of this study was to develop a highly specific, rapid and sensitive method to quantify urinary NASPC, serving as a biomarker for acrylamide exposure assessment. Isotope-labeled [13C3]NASPC was successfully synthesized and used as an internal standard. This urine mixture was directly analyzed using a newly developed liquid chromatographic/tandem mass spectrometric method coupled with an on-line clean-up system. The detection limit for this method was estimated as <5 µg l,1(0.4 pmol) on-column. The method was applied to measure the urinary level of NASPC in 70 apparently health subjects. The results showed that the NASPC urinary level was highly associated with smoking. Smokers had a significantly higher urinary NASPC level (135 ± 88 µg g,1 creatinine) than non-smokers (76 ± 30 µg g,1 creatinine). A highly sensitive and selective LC/MS/MS isotope dilution method was successfully established. With an on-line clean-up system, this system is capable of routine high-throughput analysis and accurate quantitation of NASPC in urine. This could be a useful tool for health surveillance for acrylamide exposure in a population for future study. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    A validated liquid chromatographic/tandem mass spectrometric method for the determination of phencyclidine in microliter samples of rat serum

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 1 2005
    Howard P. Hendrickson
    Abstract A liquid chromatographic/tandem mass spectrometric method is described for the determination of phencyclidine (PCP) in small volumes of rat serum (e.g. 50 µl). Samples were extracted using a mixed-mode strong cation-exchange column and then separated isocratically using a narrow-bore (2.1 mm i.d.) 3 µm Hypersil phenyl column and a mobile phase consisting of an ammonium formate buffer (pH 2.7) with 60% (v/v) methanol. Detection was accomplished using positive ion electrospray ionization in the multiple reaction monitoring mode. Mass spectra were obtained and peaks were observed at an m/z (% abundance) of 244 (100), 159 (25), and 86 (89). Tandem mass spectra were also obtained from the m/z 244 precursor ion with peaks observed at m/z 159 (100), 86 (96), and 91 (11). Optimum serum PCP sensitivity and precision were obtained at a transition of m/z 244 , 159. Matrix-associated ion suppression did not significantly affect the accuracy (100,112%) or precision (CV ,8%) of the assay. The lower limit of quantitation was 1 ng ml,1 in 50 µl of serum. The method was used to study the serum pharmacokinetics of PCP in rats after an intravenous bolus dose of PCP. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    A liquid chromatography/tandem mass spectrometric approach for the determination of gangliosides GD3 and GM3 in bovine milk and infant formulae

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 24 2006
    Lambert K. Sørensen
    A liquid chromatographic/tandem mass spectrometric method using pneumatically assisted electrospray ionisation (LC/ESI-MS/MS) was developed for the determination of gangliosides GD3 and GM3 in milk and infant formulae. The gangliosides were extracted in a chloroform/methanol/water environment and cleaned up by solid-phase extraction (SPE) on an end-capped C8 sorbent. The gangliosides were detected in negative ion mode after separation on a reversed-phase (RP) C5 analytical column. From the different ganglioside molecular species, product ions at m/z 290 corresponding to an N-acetylneuraminic acid fragment were produced in the collision cell and used in selected reaction monitoring. A standard addition technique was applied for quantification. The relative repeatability standard deviations were less than 5% for GD3 (level 10,mg/L) and 14% for GM3 (level 0.1,0.2,mg/L). Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Development and validation of a liquid chromatographic/tandem mass spectrometric method for the determination of sertraline in human plasma

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 16 2006
    Xiaoyan Chen
    A sensitive and rapid liquid chromatographic/tandem mass spectrometric method was developed and validated for the determination of sertraline in human plasma. The analyte and internal standard (IS, diphenhydramine) were extracted with 3,mL of diethyl ether/dichloromethane (2:1, v/v) from 0.25,mL plasma, then separated on a Zorbax Eclipse XDB C18 column using methanol/water/formic acid (75:25:0.1, v/v/v) as the mobile phase. The triple quadrupole mass spectrometry was applied via an atmospheric pressure chemical ionization (APCI) source for detection. The fragmentation pattern of the protonated sertraline was elucidated with the aid of product mass spectra of isotopologous peaks. Quantification was performed using selected reaction monitoring of the transitions of m/z 306,,,159 for sertraline and m/z 256,,,167 for the IS. The method was linear over the concentration range of 0.10,100,ng/mL. The intra-day and inter-day precisions, expressed by relative standard deviation, were both less than 6.7%. Assay accuracies were within ±6.9% as terms of relative error. The lower limit of quantification (LLOQ) was identifiable and reproducible at 0.10,ng/mL with a precision of 8.3% and an accuracy of 9.6%. The validated method has been successfully applied for the pharmacokinetic study and bioequivalence evaluation of sertraline in 18 healthy volunteers after a single oral administration of 50,mg sertraline hydrochloride tablets. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Development and validation of a liquid chromatography/tandem mass spectrometric method for the determination of 39 mycotoxins in wheat and maize

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2006
    Michael Sulyok
    This paper describes the first validated method for the determination of 39 mycotoxins in wheat and maize using a single extraction step followed by liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (LC/ESI-MS/MS) without the need for any clean-up. The 39 analytes included A- and B-trichothecenes (including deoxynivalenol-3-glucoside), zearalenone and related derivatives, fumonisins, enniatins, ergot alkaloids, ochratoxins, aflatoxins and moniliformin. The large number and the chemical diversity of the analytes required the application of the positive as well as the negative ion ESI mode in two consecutive chromatographic runs of 21,min each. The solvent mixture acetonitrile/water/acetic acid 79,+,20,+,1 (v/v/v) has been determined as the best compromise for the extraction of the analytes from wheat and maize. Raw extracts were diluted 1,+,1 and were injected without any clean-up. Ion-suppression effects due to co-eluting matrix components were negligible in the case of wheat, whereas significant signal suppression for 12 analytes was observed in maize, causing purely proportional systematic errors. Method performance characteristics were determined after spiking blank samples on multiple levels in triplicate. Coefficients of variation of the overall process of <5.1% and <3.0% were obtained for wheat and maize, respectively, from linear calibration data. Limits of detection ranged from 0.03 to 220,µg/kg. Apparent recoveries (including both the recoveries of the extraction step and matrix effects) were within the range of 100,±,10% for approximately half of the analytes. In extreme cases the apparent recoveries dropped to about 20%, but this could be compensated for to a large extent by the application of matrix-matched standards to correct for matrix-induced signal suppression, as only a few analytes such as nivalenol and the fumonisins exhibited incomplete extraction. For deoxynivalenol and zearalenone, the trueness of the method was confirmed through the analysis of certified reference materials. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Simple, sensitive and rapid liquid chromatographic/electrospray ionization tandem mass spectrometric method for the quantification of lacidipine in human plasma

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 7 2004
    N. V. S. Ramakrishna
    Abstract A simple, sensitive and rapid liquid chromatographic/electrospray ionization tandem mass spectrometric method was developed and validated for the quantification of lacidipine in human plasma using its structural analogue, amlodipine, as internal standard (IS). The method involves a simple single-step liquid,liquid extraction with tert -butyl methyl ether. The analyte was chromatographed on an Xterra MS C18 reversed-phase chromatographic column by isocratic elution with 20 mM ammonium acetate buffer,acetonitrile (10 : 90, v/v; pH 6) and analyzed by mass spectrometry in the multiple reaction monitoring mode. The precursor to product ion transitions of m/z 456.4 , 354.4 and m/z 409.3 , 238.3 were used to measure the analyte and the I.S., respectively. The chromatographic run time was 1.5 min and the weighted (1/x2) calibration curves were linear over the range 0.1,25 ng ml,1. Lacidipine was sensitive to temperature in addition to light. The method was validated in terms of accuracy, precision, absolute recovery, freeze,thaw stability, bench-top stability and re-injection reproducibility. The limit of detection and lower limit of quantification in human plasma were 50 and 100 pg ml,1, respectively. The within- and between-batch accuracy and precision were found to be well within acceptable limits (<15%). The analyte was stable after three freeze,thaw cycles (deviation <15%). The average absolute recoveries of lacidipine and amlodipine (IS) from spiked plasma samples were 51.1 ± 1.3 and 50.3 ± 4.9%, respectively. The assay method described here could be applied to study the pharmacokinetics of lacidipine. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Identification of dimer impurities in ampicillin and amoxicillin by capillary LC and tandem mass spectrometry

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 3 2007
    Chi-Yu Lu
    Abstract A micro-scale liquid chromatography electrospray ionization tandem mass spectrometric method was developed for the identification of polymerized impurities in ampicillin and amoxicillin in aqueous solution. Ampicillin and amoxicillin are broad-spectrum antibiotics and widely used for the treatment of human and animal infections. In this study ampicillin, amoxicillin, and their dimers were trapped in a 5-cm capillary column containing C18 sorbents. The analytes were separated on a reversed-phase column and introduced into the mass spectrometer via a nanospray ion source. An isocratic mobile phase consisting of 1% formic acid-acetonitrile (50 : 50, v/v) was used. For identification, the fragment ions of the analytes were monitored. The aim of the present study was to develop an optimized quality control method for the analysis of high molecular weight impurities of ampicillin and amoxicillin. [source]

    Determination of the ionophoric coccidiostats narasin, monensin, lasalocid and salinomycin in eggs by liquid chromatography/tandem mass spectrometry

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2005
    Leen Mortier
    A sensitive and selective liquid chromatographic tandem mass spectrometric method (LC/MS/MS) for the simultaneous detection of the ionophoric coccidiostats narasin, monensin, lasalocid and salinomycin in whole eggs has been developed. A very simple sample preparation consisting of an extraction with an organic solvent was carried out. Sample extracts were injected into the LC/MS/MS system on a C18 column and an isocratic elution was performed. Nigericin was used as internal standard. The precursor ions produced by electrospray positive ionisation were selected for collisional dissociation with argon into product ions. Validation of the methods was performed based on Commission Decision 2002/657/EC.1 CC, was found to be 1,,g/kg for all four compounds. Monitoring of Belgian egg samples in 2004 revealed that residues of salinomycin, lasalocid and monensin could be found. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Liquid chromatographic/mass spectrometry assay of bromotetrandrine in rat plasma and its application to pharmacokinetic study

    BIOMEDICAL CHROMATOGRAPHY, Issue 6 2009
    Naining Song
    Abstract A rapid and sensitive liquid chromatography,tandem mass spectrometric method (LC-MS/MS) for the determination of bromotetrandrine in rat plasma has been developed and applied to pharmacokinetic study in Sprague,Dawley (SD) rats after a single oral administration. Sample preparation involves a liquid,liquid extraction with n -hexane,dichlormethane (65:35, containing 1% 2-propanol isopropyl alcohol, v/v). Bromotetrandrine and brodimoprim (internal standard, IS) were well separated by LC with a Dikma C18 column using methanol,ammonium formate aqueous solution (20 mm) containing 0.5% formic acid (60:40, v/v) as mobile phase. Detection was performed on a triple quadrupole mass spectrometer in multiple reaction monitoring mode. The ionization was optimized using ESI(+) and selectivity was achieved using MS/MS analysis, m/z 703.0 , 461.0 and m/z 339.0 , 281.0 for bromotetrandrine and IS, respectively. The present method exhibited good linearity over the concentration range of 20,5000 ng/mL for bromotetrandrine in rat plasma with a lower limit of quantification of 20 ng/mL. The intra- and inter-day precisions were 2.8,7.5% and 3.2,8.1%, and the intra- and inter-day accuracy ranged from ,4.8 to 8.2% and ,5.6 to 6.2%, respectively. The method was successfully applied to a pharmacokinetic study after a single oral administration to SD rats with bromotetrandrine of 50 mg/kg. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Identification of key metabolites of tectorigenin in rat urine by HPLC-MSn

    BIOMEDICAL CHROMATOGRAPHY, Issue 2 2009
    Wei-Dong Zhang
    Abstract This is a report about the identification of key metabolites of tectorigenin in rat urine using high-performance liquid chromatography,electrospray ionization ion trap tandem mass spectrometric method (HPLC-ESI-MSn). Six healthy rats were administered a single dose (80 mg/kg) of tectorigenin by oral gavage. Urine was sampled for 0,24 h and centrifuged at 12,000 rpm for 10 min to obtain the supernatants, then the supernatants were purified by solid-phase extraction with a C18 cartridge. The chromatographic separation was carried out on a reversed-phase C18 column with a gradient elution program whereas acetonitrile,0.1% formic acid water was used as mobile phase. Mass spectra were acquired in negative ionization mode and a data-dependant scan was used for the identification of the key metabolites of tectorigenin in the urine samples. As a result, four phase II metabolites and the parent drug tectorigenin were found and identified in rat urine for the first time. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Determination of plasma topiramate concentration using LC-MS/MS for pharmacokinetic and bioequivalence studies in healthy Korean volunteers

    BIOMEDICAL CHROMATOGRAPHY, Issue 8 2008
    Jin-Hee Park
    Abstract A rapid, simple and validated liquid chromatography coupled to tandem mass spectrometric method (LC-MS/MS) for topiramate analysis in human plasma has been applied to pharmacokinetic and bioequivalence studies in 24 healthy male Korean volunteers. The procedure involves a simple liquid extraction of topiramate and prednisone (internal standard) with acetonitrile and separation by HPLC equipped with a Capcell Pak C18 column using acetonitrile,0.1% triethylamine (80:20, v/v) as a mobile phase. Detection was carried out on an API 2000 MS system by multiple reactions monitoring mode. The ionization was optimized using ESI(,) and selectivity was achieved by MS/MS analysis, m/z 338.0 , 77.5 and m/z 357.1 , 327.2 for topiramate and prednisone, respectively. The method had a total run time of 2.5 min and showed good linearity over a working range of 20,5000 ng/mL in human plasma with a lower limit of quantification of 20 ng/mL. No metabolic compounds were found to interfere with the analysis. The inter-day and intra-day accuracy were in the ranges of 99.24,116.63 and 93.45,108.68%, respectively, and inter-day and intra-day precisions were below 6.24 and 5.25%, respectively. This method was successfully applied for pharmacokinetic and bioequivalence studies by analysis of blood samples taken up to 96 h after an oral administration of 100 mg of topiramate in 24 healthy Korean volunteers. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Simple determination of huperzine A in human plasma by liquid chromatographic,tandem mass spectrometric method

    BIOMEDICAL CHROMATOGRAPHY, Issue 1 2007
    Yun-Xia Li
    Abstract Huperzine A is a potent, reversible acetylcholinesterase inhibitor. In the present work, a rapid and sensitive LC,MS,MS method for the determination of huperzine A in human plasma using codeine phosphate as internal standard has been developed and validated. The analyte and internal standard were extracted from plasma using ethyl acetate, chromatographed on a C18 column (5 µm, 150 × 4.6 mm i.d.) with a mobile phase consisting of 1% formic acid,methanol (40:60, v/v), and detected using a tandem mass spectrometer with a TurboIonSpray ionization interface. The run time was only 2 min. Good linearity was achieved in the range 0.126 -25.2 ng/mL and the limit of detection in plasma was 0.064 ng/mL. The average recovery for huperzine A was 83.4% from plasma. The analytical sensitivity and accuracy of this assay is adequate for characterization of huperzine A in human plasma. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Effect of dose and input rate on the brain penetration of BMS-204352 following intravenous administration to rats

    BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 6 2002
    Rajesh Krishna
    Abstract BMS-204352 is a novel maxi-K channel opener that is being developed for the treatment for stroke. The current study was designed to evaluate the plasma and brain pharmacokinetics of BMS-204352 in rats, in particular, assessing the effect of dose and input rate on brain penetration of BMS-204352. Rats (3 animals/group/time point) received a single intravenous dose of BMS-204352 as 5 mg/kg bolus, 5 mg/kg 30 min infusion, 5 mg/kg 60 min infusion, and 10 mg/kg bolus dose, into the jugular vein. Terminal blood (for plasma) and brain samples were collected for up to 9 h post-dose and samples were analyzed for the concentrations of intact BMS-204352 using a validated liquid chromatographic tandem mass spectrometric method (LC/MS/MS). As dose increased from 5 to 10 mg/kg, both BMS-204352 Cmax and AUC values increased in plasma and brain, somewhat greater in proportion to the increment in dose. Whereas the peak concentrations of BMS-204352 were affected by infusion time, overall AUCs were comparable across the bolus and infusion groups. Terminal disposition (T -half ranged from 1.6 to 2.7 h) of BMS-204352 was unaltered as a function of input rate. BMS-204352 crossed the blood,brain barrier with brain-to-plasma (B/P) ratios of approximately 7,11. Brain-to-plasma ratios appeared to be independent of dose and infusions produced somewhat higher brain penetration (B/P of ca. 11) as compared to bolus (B/P of ca. 7,8) dose. The decline of BMS-204352 in the brain paralleled that of plasma independent of the input rate and dose. Copyright © 2002 John Wiley & Sons, Ltd. [source]