Department of Clinical Biochemistry, Leeds Teaching Hospitals NHS Trust, Britannia House, Morley, Leeds LS27 0DQ, UK.
Ann Clin Biochem. 2010 Mar;47(Pt 2):111-7. doi: 10.1258/acb.2009.009172. Epub 2009 Dec 7.
Liquid chromatography linked to tandem mass spectrometry (LC/MS/MS) provides the ability to identify a range of benzodiazepines in accordance with European Union criteria and is an attractive method for the confirmation of benzodiazepines following immunoassay screening.
An LC/MS/MS method to detect and quantitate the six most common benzodiazepines/metabolites (diazepam, nitrazepam, nordiazepam, oxazepam, temazepam and 7-aminonitrazepam) was developed together with a qualitative screening method for a further 11 benzodiazepines/metabolites. These methods were used for confirmation of 250 urine samples submitted for routine drug screening by immunoassay for benzodiazepines (100 samples positive for a benzodiazepine, assay cut-off >200 microsg/L).
The lower limits of detection and quantitation were less than 2.5 and 5 microg/L for the six most common benzodiazepines. Recoveries ranged between 97% and 102% and calibration curves were linear to at least 4000 microg/L (r = 0.99). Intra and inter-assay imprecision were <10% (n = 10) and <20% (n = 15), respectively. Confirmation of benzodiazepines using LC/MS/MS was achieved for 89% of the immunoassay-positive urine samples. Of the immunoassay-negative urine samples, 31% of these demonstrated a benzodiazepine using LC/MS/MS.
The validated LC/MS/MS method developed is effective for the confirmation of immunoassay screening results for benzodiazepines. The lower limit of detection and assay specificity offers a longer window of detection and more detailed clinical information compared with immunoassay screening.
液相色谱-串联质谱（LC/MS/MS）可根据欧盟标准鉴定多种苯二氮䓬类药物，是免疫检测筛选后确证苯二氮䓬类药物的一种有吸引力的方法。
建立了同时检测和定量 6 种最常见的苯二氮䓬类药物/代谢物（地西泮、硝西泮、去甲西泮、奥沙西泮、替马西泮和 7-氨基硝西泮）的 LC/MS/MS 方法，并建立了进一步检测 11 种苯二氮䓬类药物/代谢物的定性筛选方法。这些方法用于确证 250 份尿液样本，这些样本由免疫法筛查苯二氮䓬（100 份苯二氮䓬阳性，检测截止值＞200μg/L）。
6 种最常见的苯二氮䓬类药物的检测下限和定量下限均小于 2.5μg/L 和 5μg/L。回收率在 97%至 102%之间，校准曲线至少在 4000μg/L（r=0.99）处呈线性。批内和批间精密度均＜10%（n=10）和＜20%（n=15）。使用 LC/MS/MS 对免疫测定阳性的尿液样本中 89%的样本进行了苯二氮䓬的确认。在免疫测定阴性的尿液样本中，31%的样本使用 LC/MS/MS 检测到苯二氮䓬。
建立的验证 LC/MS/MS 方法可有效确证苯二氮䓬类药物的免疫检测筛选结果。与免疫检测筛选相比，该方法的检测下限和分析特异性提供了更长的检测窗口和更详细的临床信息。
