| 摘要: |
| 人体呼出气中挥发性有机化合物（VOCs）分析已应用于环境暴露评估和疾病诊断等领域，其中肺泡气可以排除来自周围环境以及口腔和鼻腔内死腔气体的干扰，准确反映暴露及内源性代谢物水平。对采集肺泡气的Bio-VOCTM呼吸采样器转移样品至吸附管的常规操作流程进行评价及优化。使用Bio-VOCTM呼吸采样器采集含有丙酮、异戊二烯、乙醇、正丁醇、正己烷和正庚烷6种VOCs的呼出气模拟样品，比较不同方式转移至吸附管对模拟样品转移效率的影响，采用热脱附-气相色谱-质谱法（TD-GC-MS）对吸附管中样品进行分析，并将优化转移方式应用于实际人群呼出气样品分析。结果表明：按照Bio-VOCTM呼吸采样器常规转移方式，模拟样品中6种VOCs的转移效率均低于50%且不稳定；降低转移流量后，转移效率有所提高，进一步优化后转移效率可达90.0%—101.0%，相对标准偏差均小于5%。转移方式优化后，检测到的人体呼出气样品中3种VOCs的峰面积响应值显著提高（P＜0.01）。优化方式提高了使用Bio-VOCTM呼吸采样器采集肺泡气进行VOCs分析的准确性和可靠性，为肺泡气采集方法的标准化提供了科学依据。 |
| 关键词: 呼出气 Bio-VOCTM 吸附管 转移效率 优化 |
| DOI：10.7515/JEE242002 |
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| 基金项目:中国疾病预防控制中心环境与健康监测评价体系建设项目（23jcpj）；国家自然科学基金项目（92043201） |
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| Evaluation and optimization of sample transfer process for Bio-VOCTM breath sampler |
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ZHANG Xiaoyu, LIU Zhe, DONG Xiaoyan, WANG Qin
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1. National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
2. China CDC Key Laboratory of Environment and Population Health, Beijing 100021, China
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| Abstract: |
| Background, aim, and scope Examination of volatile organic compounds (VOCs) in human exhaled breath finds utility in both environmental exposure assessment and disease diagnosis. Alveolar gas, a constituent of human exhalation, serves as a reflection of both exogenous exposure and endogenous metabolism, while minimizing interference from external environmental gases and dead space gas in the oral and nasal cavities. The Bio-VOCTM breath sampler stands out as specialized commercial equipment designed for collecting alveolar gas. The gas sample collected by this sampler requires transfer to an adsorption tube for GC-MS detection, rendering the transfer efficiency of the sample from the sampler to the adsorption tube a crucial indicator for evaluating the sampler’s collection efficiency. Despite the lack of literature on the transfer efficiency of Bio-VOCTM breath samplers, this study undertakes an evaluation of the sample transfer efficiency of the Bio-VOCTM breath sampler and optimizes its traditional transfer process. Materials and methods The Bio-VOCTM breath sampler was utilized for collecting simulated exhaled breath samples containing ethanol, acetone, isoprene, n-butanol, n-hexane, and n -heptane. A comparison was conducted between the transfer efficiency observed under traditional and optimized transfer processes. The samples transferred to the adsorption tubes underwent analysis using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Subsequently, the optimization method was implemented to analyze the exhaled breath of the population. Results During traditional operation, the transfer efficiency remains below 50%, with a relative standard deviation (RSD) ranging from 11.3% to 15.6%. However, enhancements are evident by reducing the transfer flow. Following additional optimization, transfer efficiencies reach levels between 90.0% and 101.0%, with an RSD below 5%. Statistical analysis reveals a notable increase in the peak area of VOCs collected using the optimized transfer method (P＜0.01). Discussion In conventional operation, an excess transfer flow might result in insufficient adsorption efficiency between the VOCs and the adsorbent in the adsorption tube. However, despite reducing the transfer flow rate, the enhancement in transfer efficiency was not effectively achieved. This issue could be attributed to inadequate sealing of the sampler, allowing ambient gas to infiltrate the adsorption tube through the gap between the piston and the sampler. To address this, the step of transferring the sample from the sampler should be executed at a swifter flow rate to minimize ambient air introduction through the sampler gap. Furthermore, the transfer to the adsorption tube should occur at appropriate flow rates to ensure thorough sample adsorption while traversing the tube. As a result, the transfer process underwent further optimization to expedite the sample transfer from the sampler to the Tedlar bag. Subsequently, the samples were transferred from the gas bag to the adsorption tube using a gas sampling pump with a flow rate of 200 mL·min−1 in this study. Conclusions The transfer efficiency from the Bio-VOCTM breath sampler to the adsorption tube was inadequate under traditional operation, failing to meet sampling requirements. Nonetheless, through process optimization involving adjustments in the sample transfer flow rate from the sampler to the adsorption tube, notable enhancements in transfer efficiency were realized. This optimization enhances the precision and dependability of employing the Bio-VOCTM breath sampler for alveolar gas analysis. Recommendations and perspectives The optimized operational approach offers insights into the judicious utilization of the Bio-VOCTM breath sampler in exhaled breath analysis, thereby furnishing technical assistance for standardizing the process of acquiring alveolar gas. |
| Key words: exhaled breath Bio-VOCTM adsorption tube transfer efficiency optimization |
