Quantification and Stereochemical Composition of R-(−) and S-(+)-Clenbuterol Enantiomers in Bovine Urine by Liquid Chromatography–Tandem Mass Spectrometry

2019 ◽  
Vol 44 (3) ◽  
pp. 237-244
Author(s):  
Benjamín Velasco-Bejarano ◽  
Jahir Bautista ◽  
Martha E Rodríguez ◽  
Raquel López-Arellano ◽  
Roberto Arreguín-Espinosa ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Limit Of Detection ◽  
Internal Standard ◽  
High Specificity ◽  
Wilcoxon Test ◽  
Adrenergic Agonist ◽  
Limit Of Quantification ◽  
Bovine Urine ◽  
Enantiomeric Analysis ◽  
Liquid Chromatography Tandem Mass

Abstract Clenbuterol (4-amino-α-[(tert-butylamino)methyl]-3,5-dichlorobenzylalcohol) is a β2-adrenergic agonist. The consumption of meat contaminated with clenbuterol can lead to increased heart rate, blood pressure, anxiety, palpitations and skeletal muscle tremors. Several analytical methods have been developed to identify and quantify clenbuterol in different biological matrices. In this report, we have developed a specific and sensitive analytical method for quantifying clenbuterol and performed an in-depth enantiomeric analysis in bovine urine. The method was evaluated in accordance with international guidelines, and we used an isotopically labeled analog as an internal standard. The extraction efficiency for clenbuterol in bovine urine was > 98%, the limit of detection was 0.05 ng/mL and the limit of quantification was 0.10 ng/mL. Our assay showed high specificity, no carryover was observed and the assay was linear in the range 0.10–8.0 ng/mL. Fifteen bovine urine samples were analyzed (containing clenbuterol), and an enantiomeric analysis was performed. The clenbuterol concentration range was 0.10–10.56 ng/mL across these samples. The levorotatory enantiomer was detected at greater concentrations than the dextrorotatory enantiomer, the ratio being 1.7 ± 0.6 (n = 15), and a statistical difference was observed (P < 0.05) using the Wilcoxon test.

DEVELOPMENT AND VALIDATION OF RAPID AND SIMPLE BIOANALYTICAL METHOD FOR DOCETAXEL WITH ONE STEP PROTEIN PRECIPITATION

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (07) ◽  
pp. 23-32
Author(s):  
P. C. Mehendale ◽  
R. B Athawale ◽  
K. K. Singh ◽  
Keyword(s):  
Extraction Efficiency ◽  
Regression Coefficient ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Protein Precipitation ◽  
Isocratic Elution ◽  
Limit Of Quantification ◽  
Extraction Solvent ◽  
One Step ◽  
Development And Validation

A rapid and simple bio-analytical method with one step protein precipitation and extraction using acetonitrile as extraction solvent was developed for docetaxel. The extraction efficiency was 87.81% with satisfactory separation of docetaxel and IS peaks by isocratic elution with C18 column (25 cm X 4.5 mm, 0.5μm), acetonitrile and water (53:47 % V/V) as a mobile phase at ambient temperature and flow rate of 1mL/min. Paclitaxel solution in acetonitrile (10 mcg/ mL) was used as internal standard. The calibration curve was linear over the concentration range 50 – 5000 ng/mL, regression coefficient R2= 0.99936 and slope 0.00034. The limit of quantification and limit of detection were found to be 33 ng/ mL and 100 ng/mL, respectively. Coefficient of variation for within day and between the days was in the range of 10.9 to 14.9 and 12.5 to 15.05, respectively. Accuracy of the method indicated % recovery of 97.92 – 104.24%. Thus, a precise, accurate and robust method was developed and validated as per FDA guidelines.

Pharmacokinetic Study of Main Active Components of Rumex nepalensis Spreng Extract in Rats Plasma by UPLC-MS/MS

2019 ◽  
Vol 15 (4) ◽  
pp. 371-378
Author(s):  
Jin Wang ◽  
Yang Chu ◽  
Xiao Li ◽  
Navaneethakrishnan Polachi ◽  
Xue-ying Yan ◽  
...  
Keyword(s):  
Pharmacokinetic Study ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Gradient Elution ◽  
Rat Plasma ◽  
Tandem Mass ◽  
Active Components ◽  
Limit Of Quantification ◽  
Liquid Chromatography Tandem Mass ◽  
Acquity Uplc

Background: The Rumex nepalensis Spreng (RNS) is a traditional Chinese medicine containing rich anthraquinones. However, through proper investigation we have found that there were no reports on the pharmacokinetics of RNS extract in rats. </P><P> Objective: We study on the pharmacokinetic behaviors of emodin, chrysophanol and physcion after oral administration of RNS extract in rat to achieve a better understanding of further clinical application and conduct the preparation development of the herb. Methods: In the present study, a sensitive and rapid ultra-fast liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine the three anthraquinones such as chrysophanol, emodin and physcion in rat plasma along with danthron as the internal standard (IS). The analytes and IS were separated on an Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 µm) by using the mobile phase of water with 3 mM ammonium acetate and acetonitrile as gradient elution at a flow rate of 0.4 mL min -1. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by multiple reactions monitoring (MRM) of the transitions at m/z 253.1 → 225.0 for chrysophanol, 269.0 → 224.9 for emodin, 282.7→ 240.0 for physcion and m/z 239.0 → 211.0 for IS. The limit of detection and lower limit of quantification were both 2 ng mL -1 in rat plasma. Results: Good linearity of this method was obtained in the range of 2-1000 ng mL -1 , and the correlation coefficient was greater than 0.990. According to regulatory guidelines, the established method was fully validated, and the results were within acceptable limits. Conclusion: The validated method was successfully applied into a pharmacokinetic study of orally administered RNS extract in rats.

scholarly journals LC-MS/MS Quantification of Zn-α2 Glycoprotein: A Potential Serum Biomarker for Prostate Cancer

2007 ◽  
Vol 53 (4) ◽  
pp. 673-678 ◽  
Author(s):  
Olga P Bondar ◽  
David R Barnidge ◽  
Eric W Klee ◽  
Brian J Davis ◽  
George G Klee
Keyword(s):  
Prostate Cancer ◽  
Clinical Utility ◽  
Tryptic Peptide ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Intact Protein ◽  
Limit Of Quantification ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract Background: Zn-α2 glycoprotein (ZAG) is a relatively abundant glycoprotein that has potential as a biomarker for prostate cancer. We present a high-flow liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for measuring serum ZAG concentrations by proteolytic cleavage of the protein and quantification of a unique peptide. Methods: We selected the ZAG tryptic peptide 147EIPAWVPEDPAAQITK162 as the intact protein for quantification and used a stable isotope-labeled synthetic peptide with this sequence as an internal standard. Standards using recombinant ZAG in bovine serum albumin, 50 g/L, and a pilot series of patient sera were denatured, reduced, alkylated, and digested with trypsin. The concentration of ZAG was calculated from a dose–response curve of the ratio of the relative abundance of the ZAG tryptic peptide to internal standard. Results: The limit of detection for ZAG in serum was 0.08 mg/L, and the limit of quantification was 0.32 mg/L with a linear dynamic range of 0.32 to 10.2 mg/L. Replicate digests from pooled sera run during a period of 3 consecutive days showed intraassay imprecision (CV) of 5.0% to 6.3% and interassay imprecision of 4.4% to 5.9%. Mean (SD) ZAG was higher in 25 men with prostate cancer [7.59 (2.45) mg/L] than in 20 men with nonmalignant prostate disease [6.21 (1.65) mg/L, P = 0.037] and 6 healthy men [3.65 (0.71) mg/L, P = 0.0007]. Conclusions: This LC-MS/MS assay is reproducible and can be used to evaluate the clinical utility of ZAG as a cancer biomarker.

scholarly journals Analytical Procedure for the Determination of Tulathromycin in Swine Plasma

2013 ◽  
Vol 57 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak ◽  
Tomasz Błądek
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Internal Standard ◽  
Limit Of Quantification ◽  
Mode Detection ◽  
Liquid Chromatography Tandem Mass ◽  
Solid Phase Extraction Procedure ◽  
Reliable Analytical Method

Abstract For the measurement of tulathromycin distribution in swine plasma an accurate and reliable analytical method was developed. The extraction was performed with oxalic acid buffer (pH=4.0). Plasma samples were cleaned up by solid phase extraction procedure using polymeric cartriges. Chromatographic separation was achieved on a C 18 analytical column using mobile phase consisting of acetonitrile, 0.1% formic acid in gradient mode. Detection was carried out by liquid chromatography tandem mass spectrometry. Azithromycin was used as internal standard. The method has been successfully validated. The recovery from spiked samples ranged from 94% to 110%. The limit of detection was 2 ng/mL and the limit of quantification was 5 ng/mL. The method was developed to investigate the pharmacokinetics of tulathromycin in swine plasma. Applicability of the method was tested with plasma from swine administered with a single dose of tulathromycin.

scholarly journals Quantification of plasma remdesivir and its metabolite GS-441524 using liquid chromatography coupled to tandem mass spectrometry. Application to a Covid-19 treated patient

2020 ◽  
Vol 58 (9) ◽  
pp. 1461-1468 ◽  
Author(s):  
Jean-Claude Alvarez ◽  
Pierre Moine ◽  
Isabelle Etting ◽  
Djillali Annane ◽  
Islam Amine Larabi
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Half Life ◽  
Limit Of Detection ◽  
Treated Patient ◽  
Internal Standard ◽  
Therapeutic Drug ◽  
Active Metabolites ◽  
Limit Of Quantification ◽  
Positive Mode

AbstractObjectivesA method based on liquid chromatography coupled to triple quadrupole mass spectrometry detection using 50 µL of plasma was developed and fully validated for quantification of remdesivir and its active metabolites GS-441524.MethodsA simple protein precipitation was carried out using 75 µL of methanol containing the internal standard (IS) remdesivir-13C6 and 5 µL ZnSO4 1 M. After separation on Kinetex® 2.6 µm Polar C18 100A LC column (100 × 2.1 mm i.d.), both compounds were detected by a mass spectrometer with electrospray ionization in positive mode. The ion transitions used were m/z 603.3 → m/z 200.0 and m/z 229.0 for remdesivir, m/z 292.2 → m/z 173.1 and m/z 147.1 for GS-441524 and m/z 609.3 → m/z 206.0 for remdesivir-13C6.ResultsCalibration curves were linear in the 1–5000 μg/L range for remdesivir and 5–2500 for GS-441524, with limit of detection set at 0.5 and 2 μg/L and limit of quantification at 1 and 5 μg/L, respectively. Precisions evaluated at 2.5, 400 and 4000 μg/L for remdesivir and 12.5, 125, 2000 μg/L for GS-441524 were lower than 14.7% and accuracy was in the [89.6–110.2%] range. A slight matrix effect was observed, compensated by IS. Higher stability of remdesivir and metabolite was observed on NaF-plasma. After 200 mg IV single administration, remdesivir concentration decrease rapidly with a half-life less than 1 h while GS-441524 appeared rapidly and decreased slowly until H24 with a half-life around 12 h.ConclusionsThis method would be useful for therapeutic drug monitoring of these compounds in Covid-19 pandemic.

scholarly journals Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Limit Of Quantification ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Primary Secondary Amine

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.

Determination of tigecycline in turkey plasma by LC-MS/MS: validation and application in a pharmacokinetic study

2017 ◽  
Vol 20 (2) ◽  
pp. 241-249 ◽  
Author(s):  
A. Jasiecka-Mikołajczyk ◽  
J.J. Jaroszewski
Keyword(s):  
Pharmacokinetic Study ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Selected Reaction Monitoring ◽  
Limit Of Quantification ◽  
Complicated Skin ◽  
Intravenous And Oral Administration

Abstract Tigecycline (TIG), a novel glycylcycline antibiotic, plays an important role in the management of complicated skin and intra-abdominal infections. The available data lack any description of a method for determination of TIG in avian plasma. In our study, a selective, accurate and reversed-phase high performance liquid chromatography-tandem mass spectrometry method was developed for the determination of TIG in turkey plasma. Sample preparation was based on protein precipitation and liquid-liquid extraction using 1,2-dichloroethane. Chromatographic separation of TIG and minocycline (internal standard, IS) was achieved on an Atlantis T3 column (150 mm × 3.0 mm, 3.0 μm) using gradient elution. The selected reaction monitoring transitions were performed at 293.60 m/z → 257.10 m/z for TIG and 458.00 m/z → 441.20 m/z for IS. The developed method was validated in terms of specificity, selectivity, linearity, lowest limit of quantification, limit of detection, precision, accuracy, matrix effect, carry-over effect, extraction recovery and stability. All parameters of the method submitted to validation met the acceptance criteria. The assay was linear over the concentration range of 0.01-100 μg/ml. This validated method was successfully applied to a TIG pharmacokinetic study in turkey after intravenous and oral administration at a dose of 10 mg/kg at various time-points.

scholarly journals Rapid and Sensitive Method for Quantitative Determination of Lopinavir and Ritonavir in Human Plasma by Liquid Chromatography- Tandem Mass Specrtometry

2009 ◽  
Vol 6 (1) ◽  
pp. 223-230 ◽  
Author(s):  
G. A. Temghare ◽  
S. S. Shetye ◽  
S. S. Joshi
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Solid Phase ◽  
Internal Standard ◽  
Therapeutic Monitoring ◽  
Tandem Mass ◽  
Limit Of Quantification ◽  
Liquid Chromatography Tandem Mass ◽  
Sensitive Method

A rapid and sensitive liquid chromatography-mass spectrometric (LC-MS-MS) method for the simultaneous determination of lopinavir and ritonavir in human plasma using abacavir as internal standard has been developed and validated. Sample preparation of plasma involved solid phase extraction. Detection was performed using an Applied Biosystems Sciex API 2000 Mass spectrometer. The assay of lopinavir and ritonavir was linear over the range of 50 ng mL-1to 20000 ng mL-1and 20 ng mL-1to 3000 ng mL-1 respectively with a precision of <15% and accuracy in the range of 85-115%. The limit of quantification in plasma for lopinavir and ritonavir was 50 ng mL-1and 20 ng mL-1respectively. The described method has the advantage of being rapid and easy and it could be applied in therapeutic monitoring of these drugs in human plasma

scholarly journals Quantification of Tau in Cerebrospinal Fluid by Immunoaffinity Enrichment and Tandem Mass Spectrometry

2014 ◽  
Vol 60 (4) ◽  
pp. 683-689 ◽  
Author(s):  
Thomas McAvoy ◽  
Michael E Lassman ◽  
Daniel S Spellman ◽  
Zhenlian Ke ◽  
Bonnie J Howell ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cerebrospinal Fluid ◽  
Tandem Mass Spectrometry ◽  
Magnetic Beads ◽  
Internal Standard ◽  
Tandem Mass ◽  
Limit Of Quantification ◽  
Total Tau ◽  
Liquid Chromatography Tandem Mass ◽  
Full Scan

Abstract BACKGROUND Cerebrospinal fluid (CSF) tau is a common biomarker for Alzheimer disease (AD). Measurements of tau have historically been performed using immunoassays. Given the molecular diversity of tau in CSF, the selectivity of these immunoassays has often been questioned. Therefore, we aimed to develop an analytically sensitive and selective immunoaffinity liquid chromatography–tandem mass spectrometry (LC-MS/MS) (IA-MS) assay. METHODS IA-MS sample analysis involved the addition of an internal standard, immunoaffinity purification of tau using a tau monoclonal antibody coupled to magnetic beads, trypsin digestion, and quantification of a surrogate tau peptide by LC-MS/MS using a Waters Trizaic nanoTile ultraperformance LC microfluidic device. Further characterization of tau peptides was performed by full-scan MS using a Thermo Orbitrap LC-MS. CSF samples from a cohort of age-matched controls and patients with AD were analyzed by the IA-MS method as well as a commercially available immunoassay. RESULTS The IA-MS assay had intra- and interassay imprecision values of 3.2% to 8.1% CV and 7.8% to 18.9% C, respectively, a mean recovery of 106%, and a limit of quantification of 0.25 pmol/L and was able to quantify tau concentrations in all human specimens tested. The IA-MS assay showed a correlation of R2 = 0.950 against a total-tau immunoassay. In patients with AD, tau was increased approximately 2-fold. CONCLUSIONS Combining immunoaffinity enrichment with microflow LC-MS/MS analysis is an effective approach for the development of a highly selective assay to measure total tau and, potentially, other posttranslationally modified forms of tau in CSF.

scholarly journals Ultraperformance Liquid Chromatography–Tandem Mass Spectrometry Assay for Iohexol in Human Serum

2009 ◽  
Vol 55 (6) ◽  
pp. 1196-1202 ◽  
Author(s):  
Thomas M Annesley ◽  
Larry T Clayton
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Human Serum ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Structural Analog ◽  
Limit Of Quantification ◽  
Iodinated Contrast ◽  
Liquid Chromatography Tandem Mass

Abstract Background: Iohexol is an iodinated contrast dye that has been shown to be useful in the estimation of glomerular filtration rate (GFR) in patients with suspected renal insufficiency. We developed and validated an ultraperformance liquid chromatography (UPLC)–triple quadrupole mass spectrometry (MS/MS) assay for quantifying iohexol in human serum. Methods: Sample preparation involved dilution of 50 μL serum with 400 μL water, followed by protein precipitation with zinc sulfate and methanol containing the structural analog ioversol as the internal standard. After 1:20 dilution of the supernatant with water, 5 μL was injected into the UPLC-MS/MS system. Chromatography was performed using a Waters Oasis HLB 5-μm particle size, 2.1 × 20 mm column maintained at 50 °C. We used a 1-step acetonitrile/0.1% formic acid gradient to elute the compounds of interest at a common retention time of 0.96 min. The multiple reaction monitoring transitions used for integration and quantification were m/z 821.7→803.7 for iohexol and m/z 807.9→589.0 for ioversol in the electrospray positive ionization mode. Results: The assay was linear from 2.5 mg/L (lower limit of quantification) to 1500 mg/L iohexol, with a mean extraction efficiency of &gt;99%. Recovery of nominal target concentrations was 99%–102%. Interassay imprecision ranged from 7.9% at a concentration of 2.5 mg/L to 4.1% at 1000 mg/L. Ion suppression studies showed no matrix effects on the ionization of the 2 compounds. Conclusions: This rapid UPLC-MS/MS method can be successfully used for quantifying iohexol in human serum. .

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