| 摘要: |
| 采用顶空-气相色谱/质谱法联用技术测定水中的四乙基铅，对涉及的关键操作环节及重点技术问题进行了研究。结果表明，在避光条件下于4 ℃低温冷藏并密封保存，添加甲醇作为保护剂，保存时间不应超过3 d。实验选择进样口温度为220 ℃，顶空瓶压力为96.52 kPa，调节载气流量设置实际分流比为5：1，可以有效改善顶空进样测定样品时存在的不出峰、不稳定或灵敏度降低的问题。对地表水、自来水及生活污水实际样品进行四乙基铅测定和加标回收分析，加标回收率为81.0%～110%，相对标准偏差（RSD）为2.5%～7.4%，能够满足《水质 四乙基铅的测定 顶空/气相色谱〖CD*2〗质谱法》（HJ 959—2018）的测定要求。将顶空进样法与吹扫捕集法进行比较，结果表明顶空进样法稳定性更好，适合大批量四乙基铅样品的连续测定。 |
| 关键词: 顶空进样 吹扫捕集 气相色谱/质谱法 四乙基铅 |
| DOI： |
| 分类号:X832 |
| 基金项目: |
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| The Key Factors in Determination of Tetraethyl Lead in Water with Headspace Injection Gas Chromatography/Mass Spectrometry |
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PU Xue-wei, XU Zhen, DENG Shan-shan
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Yuxi City Ecological Environmental Monitoring Station of Yunnan Ecology and Environment Department, Yuxi, Yunnan 653100, China
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| Abstract: |
| A headspace injection gas chromatography mass spectrometric ( HS-GC/MS) method was used to analyze tetraethyl lead in water. The key operational steps and technical issues were studied. The results showed in sealed bottle and kept dark at 4 ℃, the storage time is no more than 3 days by adding methanol as a protective agent. By setting the inlet temperature at 220 ℃ and the headspace bottle pressure at 96.52 kPa, and adjusting the split ratio to 5∶1, it could efficiently improve the problems of no peak, instability or reduced sensitivity in the determination of tetraethyl lead samples. For standard addition analysis on real water samples, the range of recovery was 81.0% to 110%, with the RSDs ranged from 2.5% to 7.4%, it could meet the requirements set by "water quality determination of tetraethyl lead headspace /gas chromatography mass spectrometry" (HJ 959—2018). Compared with purge and trap gas chromatography mass spectrometry, headspace injection was more stable and suitable for continuous determination of large quantities of tetraethyl lead samples. |
| Key words: Headspace injection Purge and trap Gas chromatography/mass spectrometry Tetraethyl lead |
