کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1247172 | 969803 | 2007 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Determination of afloqualone in human plasma using liquid chromatography/tandem mass spectrometry: Application to pharmacokinetic studies in humans Determination of afloqualone in human plasma using liquid chromatography/tandem mass spectrometry: Application to pharmacokinetic studies in humans](/preview/png/1247172.png)
Two methods for determining the central-acting muscle relaxant afloqualone in human plasma were developed and compared using API2000 and API4000 liquid chromatography tandem mass spectrometry (LC/MS/MS) systems. In the API2000 LC/MS/MS system, afloqualone and the internal standard methaqualone were extracted from plasma using a methyl-tertiary ether. After drying the organic layer, the residue was reconstituted in a mobile phase (0.1% formic acid–acetonitrile:0.1% formic acid buffer, 80:20 v/v) and injected onto a reversed-phase C18 column. The isocratic mobile phase was eluted at 0.2 ml/min. The ion transitions monitored in multiple reaction-monitoring mode were m/z 284 → 146 and 251 → 117 for afloqualone and methaqualone, respectively.Sample preparation for the API4000 LC/MS/MS system involved simple protein precipitation with an organic mixture (methanol:10% ZnSO4 = 8:2). The ion transitions monitored in multiple reaction-monitoring mode were m/z 284 → 146 and 251 → 131 for afloqualone and methaqualone, respectively.In both assays, the coefficient of variation of the precision was less than 11.8%, the accuracy exceeded 91.5%, the limit of quantification was 0.5 ng/ml, and the limit of detection was 0.1 ng/ml for afloqualone. Two methods were used to measure the plasma afloqualone concentration in healthy subjects after a single oral 20-mg dose of afloqualone. During subsequent application of the methods, we observed that high-concentration plasma samples (>7 ng/ml) prepared using the protein precipitation method resulted in about 20% higher afloqualone concentrations than with plasma samples prepared using the liquid–liquid extraction method. We believe that this phenomenon was related to the cleanness of the sample and its chemical nature.
Journal: Talanta - Volume 73, Issue 4, 15 October 2007, Pages 635–643