Kauert Gerold F, Iwersen-Bergmann Stefanie, Toennes Stefan W
Institute of Forensic Toxicology, University of Frankfurt, Kennedyallee 104, D-60596 Frankfurt/Main, Germany.
J Anal Toxicol. 2006 May;30(4):274-7. doi: 10.1093/jat/30.4.274.
Oral fluid is considered to be an alternative to urine testing for the detection of acute ingestion of drugs. The OraSure Intercept DOA Oral Specimen Collection Device (OSCD) has been used in studies for the quantitation of Delta9-tetrahydrocannabinol (THC), but concerns have been raised. In the present study, we investigated whether the volume of oral fluid can be determined and how much THC remains adsorbed on the device. It was found that THC is markedly adsorbed onto the absorptive pad. The recovery using the standard elution procedure was only 37.8 +/- 9.4% for 10 ng/mL and 55.6 +/- 1.0% for 100 ng/mL of THC in oral fluid (n = 5 each). With an additional methanol wash, a further 25% could be eluted. Therefore, a modification of the procedure was evaluated, consisting of the addition of 2 mL of methanol to the elution buffer. THC could be completely recovered over a range of concentrations (1 to 1000 ng/mL). For the determination of the amount of oral fluid absorbed, a gravimetric approach was evaluated as the weights of the devices vary only by 0.6% relative standard deviation. After application of 0.5 mL oral fluid to pads and evaluation of the weight differences, the applied amount could be estimated with a precision of 7.5% (n = 8) and an accuracy of 6.1%. From these results it can be concluded that the OraSure OSCD is useful to collect oral fluid for reliable quantitative THC assay applying a modified elution procedure and gravimetric determination of the amount of oral fluid.
口腔液被认为是检测药物急性摄入的尿液检测的替代方法。OraSure Intercept DOA口腔样本采集装置（OSCD）已用于Delta9-四氢大麻酚（THC）定量研究，但也引发了一些担忧。在本研究中，我们调查了是否可以确定口腔液的体积以及有多少THC仍吸附在该装置上。结果发现，THC会显著吸附到吸收垫上。对于口腔液中浓度为10 ng/mL的THC，使用标准洗脱程序的回收率仅为37.8±9.4%，浓度为100 ng/mL时为55.6±1.0%（每组n = 5）。额外用甲醇洗涤，还可再洗脱25%。因此，对该程序进行了改进评估，即在洗脱缓冲液中添加2 mL甲醇。在一系列浓度（1至1000 ng/mL）范围内，THC可完全回收。为了确定吸收的口腔液量，评估了一种重量法，因为装置的重量相对标准偏差仅相差0.6%。在向垫上施加0.5 mL口腔液并评估重量差异后，施加量的估计精度为7.5%（n = 8），准确度为6.1%。从这些结果可以得出结论，OraSure OSCD可用于收集口腔液，通过改进的洗脱程序和口腔液量的重量法测定，进行可靠的THC定量分析。
