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DissertationDOI

Development of procedures for sreening for, identification and/or validated quantification of herbal drugs in blood or urine using GC-MS, LC-MS or LC-MS/MS

01 Jan 2006-
About: The article was published on 2006-01-01 and is currently open access. It has received 1 citations till now.

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Citations
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Journal Article
TL;DR: In this paper, a method was proposed for the determination of nicotine and cotinine in human urine, plasma and saliva, and the results showed that through the accurate determination of cotinines in saliva, the risk of ETS-exposed human can be predicted.

104 citations

References
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Journal ArticleDOI
TL;DR: A very sensitive and selective method for the determination of scopolamine in serum with a rapid and simple sample preparation using a capillary column gas chromatographic-ion trap tandem mass spectrometric technique.

26 citations

Journal ArticleDOI
TL;DR: This method was used successfully to measure the pharmacokinetic profiles of subjects involved in the development of an aerosol inhalation drug delivery system and established that water-based standards and controls are interchangeable with plasma-based samples.
Abstract: The authors describe a reverse-phase high-performance liquid chromatography-electrospray-tandem mass spectrometry method for the measurement of nicotine in human plasma. Samples (500 muL) with added deuterium-labeled d(3)-nicotine as an internal standard (IS) were treated with a 2-step process of ether extraction (6 mL) followed by back-extraction into 0.1% formic acid (50 muL). Chromatography was performed on a phenyl Novapak column with a mobile phase consisting of 50% 10 mM ammonium fortriate (pH 3.3) and acetonitrile (50:50, vol/vol). A flow rate of 0.2 mL/min resulted in a total analysis time of 5 minutes per sample. Mass spectrometric detection was by selected reactant monitoring (nicotine m/z 163.2 --> 130.2; IS m/z 166.2 --> 87.2). The assay was linear from 0.5 to 100 mug/L (r > 0.993, n = 9). The accuracy and imprecision of the method for quality control sampleswere 87.5% to 113% and 75%. The method described has good process efficiency, stabilized nicotine, avoided concentration steps, and most importantly minimized potential contamination. Further, we have established that water-based standards and controls are interchangeable with plasma-based samples. This method was used successfully to measure the pharmacokinetic profiles of subjects involved in the development of an aerosol inhalation drug delivery system.

19 citations

Journal ArticleDOI
TL;DR: A specific method has been developed for the quantitative determination of nicotine and its major metabolite cotinine in plasma or serum of active and passive smokers and has been demonstrated to be linear up to 1000 μg/l.
Abstract: A specific method has been developed for the quantitative determination of nicotine and its major metabolite cotinine in plasma or serum of active and passive smokers. Deuterium-labelled nicotine and cotinine were used as internal standards. The amounts of nicotine and cotinine present in a sample of plasma or serum were extracted with a simple extraction procedure (liquid-liquid or solid-phase extraction). The extracts were analysed by gas chromatography coupled with mass spectrometry using ion-trap detection. The analysis was done in positive chemical ionisation with methanol as the liquid reagent. The method has been demonstrated to be linear up to 1000 microg/l. Limits of quantification for nicotine and cotinine are 10 and 5 microg/l, respectively with liquid-liquid extraction, and 1 microg/l for each of the compounds with solid-phase extraction. The present method has been applied to several real cases.

18 citations

Journal ArticleDOI
TL;DR: A gas chromatographic-mass spectrometric procedure for the quantitation of urinary 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) has been developed and found that the inter-day standard curves were linear in the concentration range 0-300 ng/ml with a mean r = 0.9997 (n = 4).

17 citations

Journal ArticleDOI
TL;DR: A gas chromatography-mass spectrometry (GC-MS)-based screening procedure was developed for the detection of stimulant laxatives and/or their metabolites in human urine after enzymatic cleavage of conjugates followed by extractive methylation.
Abstract: A gas chromatography-mass spectrometry (GC-MS)-based screening procedure was developed for the detection of stimulant laxatives and/or their metabolites in human urine after enzymatic cleavage of conjugates followed by extractive methylation. The part of the phase-transfer catalyst remaining in the organic phase was removed by solid-phase extraction on a diol phase. The compounds were separated by capillary GC and identified by computerized MS in the full scan mode. By use of mass chromatography with the ions m/z 305, 290, 335, 320, 365, 350, 311, 326, 271, and 346, the possible presence of stimulant laxatives and/or their metabolites could be indicated. The identity of positive signals in such mass chromatograms was confirmed by comparison of the peaks underlying full mass spectra with the reference spectra. This method allowed the detection of the diphenol laxatives bisacodyl, picosulfate, and phenolphthalein and of the anthraquinone laxatives contained in plant extracts and/or their metabolites in human urine samples. The overall recoveries of the stimulant laxatives and/or their metabolites ranged between 33% and 89% with a coefficient of variation of less than 15%, and the limits of detection ranged between 10 and 25 ng/mL (S/N 3) in the full scan mode. After ingestion of the lowest therapeutic dose of sodium picosulfate, its main metabolite, bisacodyl diphenol, was detectable in urine samples for 72 hours. After ingestion of the lowest therapeutic dose of a senna extract, the main metabolite of sennosides, rhein, was detectable in urine samples for 24 hours. This procedure is part of a systematic toxicological analysis procedure for acidic drugs and poisons with the modification of enzymatic cleavage of conjugates.

17 citations