Lough P S, Fehn R
San Bernardino County Sheriff's Department, Scientific Investigations Division, CA.
J Forensic Sci. 1993 Mar;38(2):266-71.
Whether urine samples used in forensic science DUI testing can be compromised by endogenous ethanol production is a recurrent and yet unresolved issue. This study first assessed unpreserved urine samples that were collected, processed, and analyzed repeatedly over 13 to 41 days using a standard gas chromatographic procedure for ethanol analysis. Despite extensive microbial growth, ethanol was not detected in any test sample. The extent of ethanol production in samples supplemented with glucose, Candida albicans, or both was determined to evaluate the potential for ethanol production in urine samples associated with pathological conditions such as urinary tract yeast infections and diabetes mellitus. Ethanol production under each of the above treatment conditions was assessed in the presence and absence of 1% sodium fluoride as a microbial suppressant. Mean ethanol concentrations were determined for unpreserved samples containing urine only (0.003 +/- 0.005 g%), urine plus yeast (0.006 +/- 0.009 g%) and urine plus glucose (0.067 +/- 0.070 g%). Unpreserved samples supplemented with both yeast and glucose attained mean ethanol concentrations of 0.164 +/- 0.057 g% (P < 0.01). Ethanol could not be detected in any corresponding duplicate samples, which were preserved with 1% sodium fluoride. A lack of ethanol production in any of the unpreserved urine samples indicates that false DUI convictions due to endogenous ethanol production are very unlikely. And while endogenous ethanol production is possible in the presence of both glucose and contaminating C. albicans, 1% sodium fluoride completely eliminated microbial fermentation.
法医学酒驾检测中使用的尿液样本是否会因内源性乙醇生成而受到影响，是一个反复出现但尚未解决的问题。本研究首先评估了未保存的尿液样本，这些样本在13至41天内被反复采集、处理并使用标准气相色谱法进行乙醇分析。尽管有大量微生物生长，但在任何测试样本中均未检测到乙醇。通过测定添加葡萄糖、白色念珠菌或两者的样本中的乙醇生成程度，来评估与尿路感染和糖尿病等病理状况相关的尿液样本中乙醇生成的可能性。在有和没有1%氟化钠作为微生物抑制剂的情况下，评估上述每种处理条件下的乙醇生成情况。测定了仅含尿液的未保存样本（0.003±0.005 g%）、尿液加酵母（0.006±0.009 g%）和尿液加葡萄糖（0.067±0.070 g%）的平均乙醇浓度。同时添加酵母和葡萄糖的未保存样本的平均乙醇浓度达到0.164±0.057 g%（P<0.01）。在任何用1%氟化钠保存的相应重复样本中均未检测到乙醇。任何未保存的尿液样本中均未产生乙醇，这表明因内源性乙醇生成导致错误的酒驾定罪极不可能。虽然在同时存在葡萄糖和污染的白色念珠菌的情况下可能会产生内源性乙醇，但1%的氟化钠完全消除了微生物发酵。
