scholarly journals Quantitative determination of major nandrolone metabolite in human urine by gas chromatography/mass spectrometry

Author(s):  
Pavel G. Shahoika ◽  
Aliaksandr A. Ahabalayeu ◽  
Olga N. Tchekhovskaya ◽  
Yury G. Pakhadnia ◽  
Sergey A. Beliaev ◽  
...  

Nandrolone is an anabolic androgenic steroid. The use of this substance is prohibited by World Anti-Doping Agency (WADA). In National Anti-Doping Laboratory, we have developed method for quantitative determination of major nandrolone metabolite – 19-norandrosterone in human urine by GC/MS technique (Agilent 7000). Proposed method includes sample preparation of urine samples with enzymatic hydrolysis, liquid-liquid extraction followed by derivatization step with MSTFA. Deuterated 19-norandrosterone has been used as internal standard. Total run time comprised 16 min. Lower limit of quantitation accounted for 1 ng/mL. Spiked urine samples were prepared by mixing blank urine with standard solutions of 19-norandrosterone in range 1–30 ng/mL, correlation coefficient larger than 0.99. Method was verified to following validation parameters: selectivity, linearity, repeatability, accuracy, matrix effect, stability and robustness. Furthermore, measurement uncertainty was estimated. Thus, proposed method is able to detect threshold 19-norandrosterone in human urine and carry out its quantitation conforming WADA requirements.

2007 ◽  
Vol 13 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Mario Thevis ◽  
Gerd Sigmund ◽  
Anja Koch ◽  
Wilhelm Schänzer

Since January 2007, the list of prohibited substances established by the World Anti-Doping Agency includes the sympathomimetic compound tuaminoheptane (1-methyl-hexylamine, 2-heptylamine). Primarily used as a nasal decongestant drug it has been considered relevant for sports drug testing due to its stimulating properties. A confirmatory gas chromatographic-mass spectrometric procedure was developed including liquid–liquid extraction and imine formation of tuaminoheptane employing various aldehydes and ketones such as formaldehyde, acetaldehyde, benzaldehyde and acetone. Extraction and derivatisation conditions were optimised for utmost efficiency and characteristic fragment ions obtained after electron ionisation allowed for a sensitive and selective analytical assay, which was validated with regard to recovery (50%), lower limit of detection (20 ng mL−1) as well as interday- and intraday precision (< 15%). The applicability to authentic urine samples was demonstrated using administration study specimens obtained from two male persons using Rhinofluimucil (tuaminoheptane hemisulfate) for intranasal application. The administered drug was detected up to 46h after repeated topical instillation of a total of approximately 3 mg.


2007 ◽  
Vol 90 (3) ◽  
pp. 720-724
Author(s):  
Sevgi Tatar Ulu

Abstract A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-Cl). A mobile phase consisting of acetonitrile10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were &lt;0.46 and &lt;0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.


2014 ◽  
Vol 97 (2) ◽  
pp. 415-420 ◽  
Author(s):  
Bilal Yilmaz ◽  
Ali Fuat Erdem

Abstract This paper describes a GC/MS method for the determination of ibuprofen in human plasma and urine. Ibuprofen and internal standard naproxen were extractedfrom plasma and urine by using a liquid–liquid extraction method. Derivatization was carried outusing N-methyl-N-(trimethylsilyl) trifluoroacetamide. Calibration curves were linear over the concentration range of 0.05–5.0 and 0.1–10.0 μg/mL for plasma and urine, respectively. Intraday and interday precision (RSD) values for ibuprofen in plasma and urine were less than 6.31%, and accuracy (relative error) was better than 12.00%. The mean recovery of ibuprofen was 89.53% for plasma and 93.73% for urine. TheLOD was 0.015 and 0.03 μg/mL and the LOQ was 0.05 and 0.1 μg/mL for plasma and urine, respectively. The method was successfully applied to blood samples from three healthy male volunteers who had been given an oral tablet of 600 mg ibuprofen.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Walaa El-Alfy ◽  
Omnia A. Ismaiel ◽  
Magda Y. El-Mammli ◽  
Abdalla Shalaby

A simple RP-HPLC-PDA method for determination of atenolol (ATN) and trimetazidine (TMZ) in human urine and tablets has been developed. Analytes were separated on a Caltrex BI column (125× 4.0 mm, 5 μm) with 25mM potassium dihydrogen phosphate pH 3.3, methanol, and acetonitrile mobile phases. The PDA detector was operated at 210 nm for TMZ and 225 nm for ATN and the flow rate was 1.0 mL/ min. Linearity was obtained over a concentration range of (1.0-100 μg/mL) for both analytes in standard solutions and the method was successfully applied for determination of target analytes in their pharmaceutical tablets. Excellent linearity was also obtained over concentration ranges of (0.25-25 μg/mL) and (0.5-25 μg/mL) in human urine for TMZ and ATN, respectively. A simple liquid-liquid extraction was applied for urine sample clean-up and a gradient method was used for chromatographic separation. The lower limit of quantitation (LOQ) was 0.99 and 0.60 μg/mL for ATN and TMZ, respectively. The limit of detection (LOD) was 0.30 and 0.18 μg/mL for ATN and TMZ, respectively. Inter- and intraday precision and accuracy for ATN were within ±1.89% in pure form and within ±2.85% in urine samples. Inter- and intraday precision and accuracy for TMZ were within ± 3.99% in pure form and within ± 3.19% in urine samples.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Adnan A. Kadi ◽  
Rihab F. Angawi ◽  
Mohamed W. Attwa ◽  
Hany W. Darwish ◽  
Ali Saber Abdelhameed

A highly specific, sensitive, and rapid method, to quantify gemifloxacin in human urine using HPLC coupled to the triple quadrupole mass spectrometer system, was developed and validated. Gemifloxacin and ofloxacin (internal standard) were rapidly extracted from urine samples without any tedious pretreatment procedure. Urine samples were filtered through a Millex-GP, 0.22 μm syringe filter. Optimal chromatographic separation of the analytes was achieved on Zorbax SB-C18(30 mm × 2 mm i.d., 3.5 μm maintained at ambient temperature). The mobile phase consisted of 0.1% formic acid (pH 3.2) and acetonitrile (80 : 20) and a flow rate of 0.2 mL min−1for 4 min. The analytes were monitored by electrospray ionization in positive ion multiple reaction monitoring mode. The method provided a linear response (r=0.9998) from a quantitation range of 5 ng mL−1to at least 500 ng mL−1. The mean extraction recovery % of gemifloxacin from spiked human urine was 101.33 ± 2.58%. The reproducibility of the method was reliable with the intra- and inter-day precision of <2% and accuracy within 2%. The established method was reliably applied for the determination of gemifloxacin in volunteers’ urine samples with the mean recoveries of gemifloxacin from Factive tablets 320 mg > 97.0%.


Author(s):  
Devi Ramesh ◽  
Mohammad Habibuddin

Objective: The present investigation demonstrates a simple, sensitive and accurate high pressure liquid chromatographic (HPLC) method for the determination of alvimopan (AMP) in rat plasma.Methods: The chromatographic separation was achieved within 10 min by using acetonitrile: potassium dihydrogen phosphate buffer pH 3.0 adjusted with orthophosphoric acid (50:50) as mobile phase on Altima Grace Smart C-18 column (5μ; 250 × 4.6 mm) at a flow rate of 1.0 ml/min with injection volume 50 µl. The drug was extracted from plasma by liquid-liquid extraction using a mixture of methanol: acetonitrile (50:50) as a solvent. The retention times of drug and internal standard were found to be 5.17 and 6.74 min, respectively. This method was validated as per the United States Food and Drug Administration (US-FDA) guidelines.Results: The results of the validation parameters were found to be within the acceptance limits. The method was linear in the concentration range from 5-1000 ng/ml (r2= 0.9998), and the extraction recovery was found to be 78.71±3.86% for AMP. The lower limit of quantification was found to be 5ng/ml, and the stability of recovered samples at different conditions was found to be more than 95%.Conclusion: The developed method possess good selectivity, specificity, there was no interference found in the plasma blanks at retention times of AMP and Internal Standard (IS). We found a good correlation between the peak area and concentration of the drug under prescribed conditions. Furthermore, the method can also be used to estimate the pharmacokinetic parameters of AMP.Keywords: Alvimopan, Liquid-liquid extraction, Method development, Matrix effect, Plasma, Recovery, Stability, Validation


2001 ◽  
Vol 294 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Elisabet Miró-Casas ◽  
Magı́ Farré Albaladejo ◽  
Maria-Isabel Covas ◽  
Jordi Ortuño Rodriguez ◽  
Ester Menoyo Colomer ◽  
...  

2012 ◽  
Vol 5 (1) ◽  
pp. 31-36 ◽  
Author(s):  
L. Xiang ◽  
Y. Gao ◽  
D. Liu ◽  
M. Yang

An HPLC-tandem mass spectrometry method was developed for the determination of patulin (PAT) in dried medicinal hawthorn fruit, a well-known traditional medicine in China. Liquid-liquid extraction was applied in the sample preparation. Multiple reaction monitoring was performed at m/z 153/109 for PAT and m/z 317/273 for internal standard zearalenone in the negative ion mode with electrospray ionisation source. Good linearity was achieved when spiked PAT concentrations were in the range of 10-500 μg/kg, with coefficient being 0.9993. The limit of quantitation was 10 μg/kg. The extraction recoveries for the spiked PAT at concentrations of 20, 100 and 400 μg/kg were 64.5%, 64.6% and 63.9%, respectively, with relative standard deviations of 1.25%, 2.82% and 2.61%. The intra-day and inter-day precision were in the range of 2.2-9.6% and 5.9-6.4%. This rapid, sensitive and reliable method was applied in 25 batches of medicinal hawthorn fruit, in which PAT was detected in 8 batches, including those that were baked or charred.


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