scholarly journals A Simple Method for Quantification of Five Urinary Porphyrins, Porphobilinogen and 5-Aminolevulinic Acid, Using Liquid Chromatography Tandem Mass Spectrometry

2017 ◽  
Author(s):  
Ozlem Dogan ◽  
Muhittin A. Serdar ◽  
Koza Murat ◽  
Cigdem Sonmez ◽  
Emre İspir ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Aminolevulinic Acid ◽  
Tandem Mass ◽  
Simple Method ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Urinary Porphyrins

scholarly journals Analysis of Methylmalonic Acid in Plasma by Liquid Chromatography–Tandem Mass Spectrometry

2006 ◽  
Vol 52 (4) ◽  
pp. 754-757 ◽  
Author(s):  
Anne Schmedes ◽  
Ivan Brandslund
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Methylmalonic Acid ◽  
Cobalamin Deficiency ◽  
Tandem Mass ◽  
Simple Method ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract Background: Methylmalonic acid (MMA) is a biochemical marker for cobalamin deficiency, particularly in cases where the cobalamin concentration is moderately decreased or in the low-normal range. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) with electrospray ionization is a rapid, robust method that has been used in MMA analysis. We developed a simple method combining solid-phase extraction (SPE) and derivatization to prepare serum or plasma for LC-MS/MS analysis of MMA. Methods: Deuterated internal standard d3-MMA was added to serum or plasma before SPE on strong anion-exchange (SAX) columns. After elution with HCl–butanol (10:90 by volume) and addition of 1 g/L formic acid, the samples were simultaneously derivatized and evaporated by heating to 70 °C for 15 min followed by 54 °C overnight in uncapped vials. Acetonitrile and 1 g/L formic acid were added to the samples before injection into the LC-MS/MS system. MMA and d3-MMA were quantified in the multiple-reaction monitoring mode. Calibrators were prepared in serum by the standard addition method. Results: The MMA assay was linear up to 200 μmol/L. Interassay CVs were 6.7%, 5.0%, and 5.0% for mean concentrations of 0.15, 0.36, and 0.65 μmol/L, respectively. Conclusions: Our simplified sample preparation and derivatization method is suitable for use in MMA analyses. MMA elutes with the derivatization reagent, and derivatization and evaporation are performed simply by leaving the uncapped vials in a heating block overnight. The method shows good linearity and precision.

scholarly journals Validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to detect cannabinoids in whole blood and breath

2020 ◽  
Vol 58 (5) ◽  
pp. 673-681 ◽  
Author(s):  
Jacqueline A. Hubbard ◽  
Breland E. Smith ◽  
Philip M. Sobolesky ◽  
Sollip Kim ◽  
Melissa A. Hoffman ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Whole Blood ◽  
Matrix Effects ◽  
Tandem Mass ◽  
Simple Method ◽  
Safe Driving ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

AbstractBackgroundThe widespread availability of cannabis raises concerns regarding its effect on driving performance and operation of complex equipment. Currently, there are no established safe driving limits regarding ∆9-tetrahydrocannabinol (THC) concentrations in blood or breath. Daily cannabis users build up a large body burden of THC with residual excretion for days or weeks after the start of abstinence. Therefore, it is critical to have a sensitive and specific analytical assay that quantifies THC, the main psychoactive component of cannabis, and multiple metabolites to improve interpretation of cannabinoids in blood; some analytes may indicate recent use.MethodsA liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to quantify THC, cannabinol (CBN), cannabidiol (CBD), 11-hydroxy-THC (11-OH-THC), (±)-11-nor-9-carboxy-Δ9-THC (THCCOOH), (+)-11-nor-Δ9-THC-9-carboxylic acid glucuronide (THCCOOH-gluc), cannabigerol (CBG), and tetrahydrocannabivarin (THCV) in whole blood (WB). WB samples were prepared by solid-phase extraction (SPE) and quantified by LC-MS/MS. A rapid and simple method involving methanol elution of THC in breath collected in SensAbues® devices was optimized.ResultsLower limits of quantification ranged from 0.5 to 2 μg/L in WB. An LLOQ of 80 pg/pad was achieved for THC concentrations in breath. Calibration curves were linear (R2>0.995) with calibrator concentrations within ±15% of their target and quality control (QC) bias and imprecision ≤15%. No major matrix effects or drug interferences were observed.ConclusionsThe methods were robust and adequately quantified cannabinoids in biological blood and breath samples. These methods will be used to identify cannabinoid concentrations in an upcoming study of the effects of cannabis on driving.

scholarly journals Simultaneous Determination of Etomidate and Its Major Metabolite, Etomidate Acid, in Urine Using Dilute and Shoot Liquid Chromatography–Tandem Mass Spectrometry

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4459 ◽  
Author(s):  
Yu-Kyung Jung ◽  
Soo Young You ◽  
Seon-Yeong Kim ◽  
Jin Young Kim ◽  
Ki-Jung Paeng
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Reversed Phase ◽  
Weighting Factor ◽  
Tandem Mass ◽  
Simple Method ◽  
Column Temperature ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Etomidate (ET) is a commonly used sedative-hypnotic agent such as propofol to induce anesthesia, and it is rapidly metabolized to etomidate acid (ETA) in liver. Herein, a simple method to determine ET and ETA in urine simultaneously was developed using liquid chromatography–tandem mass spectrometry (LC–MS/MS). A simple sample preparation method reduced the total analysis time. For all analytes, the separation was achieved in 6.5 min using reversed-phase chromatography with gradient elution. The best separation and detection of ETA was achieved using a porous graphitic carbon column. The column temperature was maintained at 30 °C to improve the efficiency and sensitivity. The calibration curves were linear over the concentration ranges of 0.4–120.0 ng/mL (ET) and 1.0–300.0 ng/mL (ETA), obtained with a weighting factor of 1/x2. The coefficients of determination (r2) were greater than 0.9958. The lower limits of quantification were 0.4 ng/mL (ET) and 1.0 ng/mL (ETA), intra-day (n = 6) and inter-day (n = 24) precision values for all compounds were less than 10.2% and 8.4%, respectively, while the intra- and inter-day accuracies were in the −9.9–2.9%, and −7.0–0.6%. The applicability of the method was examined by analyzing the urine samples obtained from ET users.

scholarly journals SIMULTANEOUS QUANTIFICATION OF TAMOXIFEN AND 4-HYDROXY-N-DESMETHYLTAMOXIFEN LEVELS IN HUMAN PLASMA BY LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY: DEVELOPMENT AND APPLICATION IN BREAST CANCER PATIENTS

2018 ◽  
Vol 10 (1) ◽  
pp. 370
Author(s):  
Yahdiana Harahap ◽  
Nathania Leony ◽  
Letare Merry Chresia Silalahi ◽  
Rizka Andalusia
Keyword(s):  
Breast Cancer ◽  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Plasma Levels ◽  
Tandem Mass ◽  
Simple Method ◽  
Simultaneous Quantification ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Objective: This study was aimed to develop a highly sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodfor the simultaneous quantification of tamoxifen, endoxifen, and clomiphene (internal standard) levels in human plasma.Methods: Plasma samples from 40 patients with breast cancer were prepared through liquid–liquid extraction in ethyl acetate, and chromatographicseparation was performed on an Acquity UPLC BEH C18 column (1.7 μm, 2.1 mm×100 mm). The sample was eluted within 6.50 min at a flow rate of0.200 ml/min under a gradient of 0.2% formic acid and acetonitrile. The analytes were then quantified through triple quadrupole MS with electrosprayionization in the positive ion mode and multiple reaction monitoring.Results: The method was successfully used to quantify the plasma levels of tamoxifen and endoxifen, yielding respective measurement rangesof 42.19–249.23 ng/ml and 1.52–26.62 ng/ml. Overall, this detection method was sensitive, with lower limits of quantitation of 0.625 ng/ml fortamoxifen and 0.125 ng/ml for endoxifen. In addition, this method was precise and accurate, with a between-run variation range of 5.19–12.38% and%diff range of −10.82%–+13.10%.Conclusion: This method demonstrated that approximately 80% of patients had plasma levels of endoxifen exceeding the expected clinical threshold(5.9 ng/ml). This rapid and simple method could be used to monitor tamoxifen metabolism and adjust doses as needed to achieve maximumeffectiveness.

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