PT-GC-CAFS联用技术测定污水处理厂外排水中烷基汞残留量

建立了吹扫捕集-气相色谱-冷原子荧光(PT-GC-CAFS)联用技术、多功能自动进样器进样测定污水处理厂外排水中烷基汞残留量的方法。用烷基化试剂直接衍生,吹扫捕集吸附/富集,以PEG20M填充柱为分离柱,用冷原子荧光作为检测器进行测定,整体分析工作在10 min内完成。在所选实验条件下,方法对所测甲基汞、乙基汞的线性相关系数分别为0.999 9、1.000,最低检出限分别为0.002、0.003 ng/L,相对标准偏差为1.4%~10.2%,2.3%~9.7%;在不同质量浓度水平上进行加标回收率实验,甲基汞的回收率为93.7%~101.7%,乙基汞为94.1%~103.6%。该方法用于污水处理厂外排水中烷基汞残留量的分析测定,结果令人满意。

Determination of the Alkyl Mercury Residue in External Drainage of Partial of Sewage Treatment Plants by Purging Capture-Gas Chromatography-Cold Atomic Fluorescence Spectrometry

A confirmative method was developed with purge and trap-GC separation-cold atomic fluorescence spectrophotometer (PT-GC-CAFS) to detect the residues of alkyl mercury in external drainage of sewage treatment plants by multifunctional automatic sampler. Using direct derivative alkyl mercury by Alkylating reagent, adsorption/enrichment by PT, with PEG20M packed column for separation column, and with cold atomic fluorescence spectrophotometer as a detector to detect mercury in environmental water samples, the overall analysis of the work to be done within 10 min. The method showed that good linear correlation coefficient of methyl mercury's and ethyl mercury's was 0.999 9 and 1.000, the relative standard deviation was (RSD=1.4%-10.2%)and (RSD=2.3%-9.7%), respectively.With different quality levels to Standard addition recovery test sample, the recovery rate of methyl mercury was 93.7%-101.7%, ethyl mercury was 94.1%-103.6%. The method was applied to determine the alkyl mercury residue in external drainage samples of sewage treatment plants.The results were satisfactory.