Quantitative MALDI Tandem Mass Spectrometric Imaging of Cocaine from Brain Tissue with a Deuterated Internal Standard

2012 ◽  
Vol 85 (2) ◽  
pp. 1081-1089 ◽  
Author(s):  
David A. Pirman ◽  
Richard F. Reich ◽  
András Kiss ◽  
Ron M. A. Heeren ◽  
Richard A. Yost
Keyword(s):  
Brain Tissue ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Tandem Mass ◽  
Mass Spectrometric Imaging ◽  
Tandem Mass Spectrometric ◽  
Deuterated Internal Standard

scholarly journals Enantioselective Determination Of S- And R-Isomers Of Ibuprofen In Plasma By Ultra-Performance Liquid Chromatography – Tandem Mass Spectrometry

2020 ◽  
Vol 15 (1) ◽  
pp. 40-46
Author(s):  
V.O. DOROSCHUK ◽  
V.Ye. Sabko ◽  
O.V. Ivashko ◽  
L.O. POPOVA ◽  
A.S. Shalamay
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Tandem Mass ◽  
Ibuprofen Enantiomers ◽  
Tandem Mass Spectrometric

A new method of enantioselective determination of S- and R-isomers of ibuprofen in human plasma by ultraperformance liquid chromatography with tandem mass spectrometric detection using solid-phase extraction was developed. For enantioselective separation of ibuprofen isomers, a LUX Cellulose-3 chiral chromatographic column was used. Complete separation of the enathiomer peaks is achieved in the isocratic elution conditions with a mobile phase ratio of 0.05 % formic acid solution (%): methanol (%) = 30 : 70 (v/v) and a flow rate of 0.2 mL/min. The mass spectrometric detection was performed at negative ionization mode with multiple reaction monitoring, using the transitions at 205.13 > 161.14 Da and 208.09 > 164.03 Da for ibuprofen enantiomers and deuterated ibuprofen (internal standard), respectively. The method validation included the evaluation of the selectivity, linearity, lower limit of quantification (LLOQ), within-run and between-run precision and accuracy. The LLOQ for the two enantiomers was 100 ng/mL in plasma. The calibration curves showed good linearity of each enantiomers in the ranges from 100 to 60000 ng/mL. The method was successfully applied to a pharmacokinetic study of ibuprofen enantiomers in human plasma.

scholarly journals Ultra-performance liquid chromatography–tandem mass spectrometric determination of ramipril in human plasma

2020 ◽  
Vol 19 (4) ◽  
pp. 851-857
Author(s):  
Sherif A. Abdel-Gawad
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Internal Standard ◽  
The United States ◽  
Ultra Performance Liquid Chromatography ◽  
Mass Spectrometric ◽  
Pharmacokinetic Studies ◽  
Tandem Mass ◽  
Liquid Chromatography Tandem Mass ◽  
Tandem Mass Spectrometric

Purpose: To develop a sensitive and accurate ultra-performance liquid chromatography–tandem mass spectrometric (UPLC-MS) method for quantification of ramipril in human plasma.Methods: Ramipril was extracted from biological fluid using equal volumes of n-hexane and propanol (1:1, v/v), and then chromatographed in a suitable C18 column with methanol: 0.1 % HCOOH (4: 1, v/v) as mobile phase. Atorvastatin was used as an internal standard for the  chromatographic separation and quantification. The method was validated according to the United States Food and Drug Administration guidelines for standard indices.Results: Ramipril was determined in the concentration range 0.05 and 1000 ng/mL the validation procedure exhibited a correlation coefficient of 0.9979 + 0.002 (p = 0.05). The studied drug was quantified with lower ceiling of 0.05 ng/mL, and showed an accuracy of 105.00 %.Conclusion: A sensitive UPLC-MS analytical method has been successfully developed for the quantification of ramipril in human plasma. This method can be applied efficiently for the quantification of ramipril in bioavailability and pharmacokinetic studies. Keywords: Liquid chromatography–tandem mass, Ramipril, Stability, Biological fluids, Plasma

scholarly journals Residues of Chlormequat and Mepiquat in Grain—Results from the Danish National Pesticide Survey

1999 ◽  
Vol 82 (2) ◽  
pp. 331-336 ◽  
Author(s):  
René K Juhler ◽  
Martin Vahl
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Human Consumption ◽  
Tandem Mass ◽  
Internal Standards ◽  
Limit Of Determination ◽  
Maximum Residue Limits ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic

Abstract The objective of the present work was to establish information on chlormequat and mepiquat residues in grain for human consumption. Chlormequat (2- chloro-N,N,N-trimethylethylammonium, CAS RN 7003-89-6) and mepiquat (1,1-dimethylpiperid- inium, CAS RN 15302-91-7) are plant growth regulators used to stabilize stalks in cereals. The study was part of the Danish National Pesticide Survey, managed by the Danish Veterinary and Food Administration. Samples were collected in autumn 1997. Residue contents were determined with a newly developed liquid chromatographic- tandem mass spectrometric (LC-MS/MS) method for chlormequat analysis. The method was extended to include mepiquat in the present study. Quantitation was done by the internal standards method, using mass chromatograms of the most intense daughter ions of mepiquat (m/z 98), chlormequat (m/z 58), and [13C]-chlormequat (m/z 61, internal standard). For chlormequat, the overall limit of detection (LD) was 6 μg/kg and the limit of determination (LOD) was 10 μg/kg. For mepiquat, LD was 2 μg/kg and LOD was 3 μg/kg. Of 77 samples analyzed, 51 contained chlormequat and 11 contained mepiquat. The highest levels of chlormequat were found in samples of oatmeal (3.76 mg/kg) and rye (1.08 mg/kg). In 9 rye grain samples containing chlormequat, 5 also contained mepiquat. However, in all samples analyzed, the residues of chlormequat and mepiquat were below maximum residue limits.

scholarly journals Quantification of Amiridine in Human Plasma by High-Performance Liquid Chromatography Coupled with Electrospray Tandem Mass Spectrometry

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Igor I. Miroshnichenko ◽  
Angelina I. Platova
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Pharmacokinetic Studies ◽  
Tandem Mass ◽  
Ionization Source ◽  
Limit Of Quantification ◽  
Tandem Mass Spectrometric

The aim of this study was to develop and validate a high-performance liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for analysis of the amiridine in human plasma. The analyte and internal standard (IS), zolpidem, were extracted from human plasma by solid phase extraction (SPE with SOLA cartridges) and separated on a Zorbax SB-C18 column using methanol and 0.2% formic acid in water as mobile phase. Detection was performed using an electrospray ionization source and mass spectrometric positive multireaction monitoring mode (+MRM) at a voltage capillary of +2000 V. The assay was linear over the concentration range 0.5–200 ng/mL with the lowest limit of quantification (LLOQ) of 0.5 ng/mL. The method also afforded satisfactory results in terms of the sensitivity, specificity, precision (intra- and interday %), accuracy, recovery, and the stability of the analyte under various conditions. The method can be successfully applied to pharmacokinetic studies.

scholarly journals Newborn Screening for Hepatorenal Tyrosinemia: Tandem Mass Spectrometric Quantification of Succinylacetone

2006 ◽  
Vol 52 (3) ◽  
pp. 482-487 ◽  
Author(s):  
Johannes Sander ◽  
Nils Janzen ◽  
Michael Peter ◽  
Stefanie Sander ◽  
Ulrike Steuerwald ◽  
...  
Keyword(s):  
Newborn Screening ◽  
False Positive ◽  
False Negative ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Absolute Methanol ◽  
Tandem Mass ◽  
Screening Programs ◽  
Blood Spots ◽  
Tandem Mass Spectrometric

Abstract Background: False-positive and false-negative results occur in current newborn-screening programs for hepatorenal tyrosinemia, which measure tyrosine concentrations in blood spots, sometimes in combination with other metabolites, including succinylacetone. We present our experience with a newly described method for succinylacetone quantification in routine newborn screening. Methods: Succinylacetone was extracted from blood spots that had already been extracted with absolute methanol for acylcarnitine and amino acid analysis. The solvent was acetonitrile–water (80:20 by volume) containing formic acid, hydrazine hydrate, and 100 nmol/L 5,7-dioxooctanoic acid as internal standard. Analysis was performed by tandem mass spectrometry in a separate run. Results: Of 61 344 samples, 99.6% had succinylacetone concentrations ≤5 μmol/L. With a cutoff of 10 μmol/L, no false-positive results were obtained. In 2 patients, the succinylacetone concentrations in the dried blood spots from the 36th and 56th hours of life were 152 and 271 μmol/L, respectively, and the tyrosine concentrations were 54 and 129 μmol/L. Hepatorenal tyrosinemia was subsequently confirmed in both patients. Retrospective analysis of the neonatal screening samples of 2 additional known patients revealed increased succinylacetone concentrations of 46 and 169 μmol/L, respectively. Conclusions: Tandem mass spectrometric quantification directly from residual blood spots is a useful method for the early detection of hepatorenal tyrosinemia in newborn-screening programs.

scholarly journals A Validated High-Performance Liquid Chromatography-Tandem Mass Spectrometric (Lc-Ms/Ms) Method for Simultaneous Determination of R(+)-Ketorolac and S(−)-Ketorolac in Human Plasma and Its Application to a Bioequivalence Study

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Sabyasachi Patri ◽  
Anil K. Patni ◽  
Sunil S. Iyer ◽  
Arshad H. Khuroo ◽  
Tausif Monif ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Bioequivalence Study ◽  
Mass Spectrometric ◽  
Tandem Mass ◽  
Liquid Chromatography Tandem Mass ◽  
Tandem Mass Spectrometric

We report a selective, accurate, and reproducible liquid chromatography-tandem mass spectrometric (LC-MS/MS) method that employs solid phase extraction for quantification of ketorolac enantiomers in human plasma. Resolution of R(+)-ketorolac and S(−)-ketorolac was achieved using a Chiral-AGP column and a mobile phase of ammonium formate buffer (10 mM, pH ):acetonitrile (85 : 15, v/v and 70 : 30, v/v) in a gradient time program. S(+)-etodolac was used as the internal standard (IS). Quantification was achieved using a positive electrospray ionization (ESI+) interface under multiple reaction monitoring (MRM) condition. The method was validated over the concentration range of 9.36–1198.69 ng/ml for R(+)-ketorolac and 6.07–776.74 ng/ml for S(−)-ketorolac. Matrix effect was found negligible and the method showed good performances in terms of accuracy (89.6–102.7%) and precision (1.7–6.7%) for both enantiomers. Extraction recoveries of R(+)-ketorolac, S(−)-ketorolac, and S(+)-etodolac were 82.04, 70.94, and 93.90%, respectively. Results of all stability exercises in human plasma were within acceptable limits. The method was successfully applied to a single dose cross over bioequivalence study in healthy human male volunteers. Incurred Sample Reanalysis (ISR) was performed by randomly selecting 10% of total subject samples of the study using Statistical Analysis Software (SAS). Values of 91.1% for R (+)-ketorolac and 83.5% for S(−)-ketorolac indicated good acceptance for ISR.

scholarly journals Development and Validation of a Liquid Chromatographic/Tandem Mass Spectrometric Method for Determination of Tetracycline in Human Plasma: Application to Bioequivalence Study

2008 ◽  
Vol 91 (4) ◽  
pp. 731-738 ◽  
Author(s):  
Liberato Brum ◽  
Ana Maria Pugens ◽  
Mariely Camila Pritsch ◽  
Patricia Bertuol Mantovani ◽  
Maurício Bedim dos Santos ◽  
...  
Keyword(s):  
Human Plasma ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Tandem Mass ◽  
Mass Spectrometric Method ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic

Abstract A fast, sensitive, and specific liquid chromatographic/tandem mass spectrometric method was developed and validated for determination of tetracycline in human plasma. Tetracycline and oxytetracycline [internal standard (IS)] were extracted from the plasma by protein precipitation. The mobile phase consisted of acetonitrileformic acid 0.1 (48 + 52, v/v), run at a flow rate of 1 mL/min (split 1:5). Detection was performed by positive electrospray ionization in multiple reaction monitoring mode, monitoring the transitions 444.8 > 410.0 and 461.0 > 426.0 for tetracycline and IS, respectively. The analysis was performed in 3.5 min and the method was linear in the plasma concentration range of 506000 ng/mL. The mean extraction recoveries for tetracycline and IS from plasma were 92.14 and 94.04, respectively. Method validation investigated parameters such as the linearity, precision, accuracy, specificity, and stability, giving results within the acceptable range. The proposed method was successfully applied for determination of tetracycline in human plasma samples to support bioequivalence studies.

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