Teflon AF 2400管冷蒸气发生-原子荧光法分析烟草中的痕量汞

采用具有高气体渗透性和紫外光透过性的无定形聚四氟乙烯管(Teflon AF-2400)作为蒸气发生原子荧光系统的气液分离器和检测池,建立了微型化汞蒸气发生原子荧光检测系统。考察了Teflon AF-2400管长度、还原剂种类和浓度、酸介质种类和浓度、进样流速以及氩气流速对测量体系的影响。在优化实验条件下,该方法的线性范围为0.07~10μg/L(r=0.998 0),检出限为0.02μg/L,相对标准偏差(n=11)为3.3%。该系统体积小、样品消耗少、灵敏度高。方法已成功应用于卷烟样品中汞含量的检测,回收率为97%~102%。

Determination of Trace Hg in Tobacco by Teflon AF 2400 Tube Cold Vapor Generation Atomic Fluorescence Spectrometry

A novel miniature cold vapor generation atomic fluorescence spectrometry was developed using amorphous Teflon AF-2400 tube as the gas-liquid separator and detection cell for the determination of Hg in tobacco,based on the Teflon AF-2400 tube′s excellent gas transport behavior and high UV transparence.The effects of length of Teflon AF-2400,type and concentration of reducing agent,type and concentration of acid medium,flow rate of sample and Ar on the system were investigated in detail.Under the optimal conditions,the calibration curve was linear in the range of 0.07-10 μg/L with detection limit of 0.02 μg/L.The relative standard deviation(RSD) was 3.3% for eleven consecutive measurements of 0.50 μg/L Hg standard solution.The novel system showed the advantages of micro-scale,low sample consumption and high sensitivity.The method was successfully used in the determination of Hg in tobacco sample with recoveries of 97%–102%.