Hopkins Danielle L, Weaver Madeline L, Sosnoff Connie, Ahamed Rayaj, Wang Lanqing, Seyler Tiffany H
CDC/NCEH/DLS/TVB, Atlanta, Georgia, United States.
Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, United States.
J Anal Toxicol. 2025 Jul 3. doi: 10.1093/jat/bkaf059.
Tobacco cigarette smoking is the leading cause of preventable diseases and death in the US. Exposure to secondhand smoke (SHS) can also cause heart disease, lung cancer, and respiratory illness. Cotinine (COT) and trans-3'-hydroxycotinine (HCT) are the primary metabolites of nicotine, the main addictive alkaloid in tobacco products. For many years, we have measured serum levels of COT and HCT in National Health and Nutritional Examination Survey (NHANES) participants to monitor exposure of the U.S. population to active smoking and SHS. As exposure to SHS is decreasing, a more sensitive analytical method is needed to detect the lower levels of these biomarkers for SHS assessment. We developed and validated a new automated method for the detection of COT and HCT in human serum. We implemented a new liquid handling automation system to aliquot and prepare samples using supported liquid extraction. Samples were analyzed by liquid chromatography-tandem mass spectrometry. The new automated sample preparation method increases sample throughput by reducing sample cleanup time to 2 hours for preparing a 96-well plate. The method has excellent sensitivity, specificity, precision (<10%), and accuracy (±15%). We were able to lower the estimated limit of detection (LOD) for COT by 33% and HCT by 73% from our previous LOD. The new LODs for COT and HCT are 0.010 ng/mL and 0.004 ng/mL, respectively. These lower LODs would enable better detection of SHS in future NHANES surveys.
在美国，吸烟是可预防疾病和死亡的主要原因。接触二手烟（SHS）也会导致心脏病、肺癌和呼吸系统疾病。可替宁（COT）和反式-3'-羟基可替宁（HCT）是尼古丁的主要代谢产物，尼古丁是烟草制品中的主要成瘾生物碱。多年来，我们在国家健康与营养检查调查（NHANES）参与者中测量了COT和HCT的血清水平，以监测美国人群接触主动吸烟和二手烟的情况。随着二手烟暴露的减少，需要一种更灵敏的分析方法来检测这些生物标志物的较低水平，以进行二手烟评估。我们开发并验证了一种用于检测人血清中COT和HCT的新自动化方法。我们实施了一种新的液体处理自动化系统，使用支持液液萃取来等分和制备样品。样品通过液相色谱-串联质谱法进行分析。这种新的自动化样品制备方法通过将制备96孔板的样品净化时间缩短至2小时，提高了样品通量。该方法具有出色的灵敏度、特异性、精密度（<10%）和准确度（±15%）。与之前的检测限相比，我们能够将COT的估计检测限（LOD）降低33%，将HCT的检测限降低73%。COT和HCT的新检测限分别为0.010 ng/mL和0.004 ng/mL。这些更低的检测限将有助于在未来的NHANES调查中更好地检测二手烟。
