Stowell A R, Gainsford A R, Gullberg R G
Environmental Science and Research Ltd (ESR), P.O. Box 50348, Porirua, New Zealand.
Forensic Sci Int. 2008 Jul 4;178(2-3):83-92. doi: 10.1016/j.forsciint.2008.02.005. Epub 2008 Mar 26.
Paired blood and breath alcohol concentrations (BAC, in g/dL, and BrAC, in g/210 L), were determined for 11,837 drivers apprehended by the New Zealand Police. For each driver, duplicate BAC measurements were made using headspace gas chromatography and duplicate BrAC measurements were made with either Intoxilyzer 5000, Seres 679T or Seres 679ENZ Ethylometre infrared analysers. The variability of differences between duplicate results is described in detail, as well as the variability of differences between the paired BrAC and BAC results. The mean delay between breath and blood sampling was 0.73 h, ranging from 0.17 to 3.1 8h. BAC values at the time of breath testing were estimated by adjusting BAC results using an assumed blood alcohol clearance rate. The paired BrAC and time-adjusted BAC results were analysed with the aim of estimating the proportion of false-positive BrAC results, using the time-adjusted BAC results as references. When BAC results were not time-adjusted, the false-positive rate (BrAC>BAC) was 31.3% but after time-adjustment using 0.019 g/dL/h as the blood alcohol clearance rate, the false-positive rate was only 2.8%. However, harmful false-positives (defined as cases where BrAC>0.1 g/210L, while BAC< or =0.1g/dL) occurred at a rate of only 0.14%. When the lower of duplicate breath test results were used as the evidential results instead of the means, the harmful false-positive rate dropped to 0.04%.
对11837名被新西兰警方逮捕的司机进行了配对血液和呼气酒精浓度（血液酒精浓度，单位为g/dL；呼气酒精浓度，单位为g/210L）测定。对于每位司机，使用顶空气相色谱法进行两次血液酒精浓度测量，使用Intoxilyzer 5000、Seres 679T或Seres 679ENZ Ethylometre红外分析仪进行两次呼气酒精浓度测量。详细描述了重复结果之间差异的变异性，以及配对的呼气酒精浓度和血液酒精浓度结果之间差异的变异性。呼气和血液采样之间的平均延迟为0.73小时，范围为0.17至3.18小时。通过使用假定的血液酒精清除率调整血液酒精浓度结果，来估计呼气测试时的血液酒精浓度值。以时间调整后的血液酒精浓度结果为参考，分析配对的呼气酒精浓度和时间调整后的血液酒精浓度结果，以估计呼气酒精浓度假阳性结果的比例。当血液酒精浓度结果未进行时间调整时，假阳性率（呼气酒精浓度>血液酒精浓度）为31.3%，但使用0.019 g/dL/h作为血液酒精清除率进行时间调整后，假阳性率仅为2.8%。然而，有害假阳性（定义为呼气酒精浓度>0.1 g/210L，而血液酒精浓度≤0.1g/dL的情况）的发生率仅为0.14%。当使用两次呼气测试结果中的较低值作为证据结果而非平均值时，有害假阳性率降至0.04%。
