Cheng Xianhao, Peterkin Earl, Narangajavana Kanthaka
Bureau of Laboratory Services, Philadelphia Water Department, 1500 E. Hunting Park Ave., Philadelphia, PA 19124, USA.
Water Environ Res. 2007 Apr;79(4):442-6. doi: 10.2175/106143006x111871.
This paper presented a modified method for the analysis of volatile organic sulfides (VOS) simultaneously with volatile organic compounds (VOC) in wastewater using purge-and-trap with gas chromatography/ mass spectrometry. Calibration standards were prepared using filtered and nitrogen-purged VOS-free wastewater, acidified to pH 1.4. Samples were also acidified to pH 1.4. This approach minimized the oxidation of methanethiol to dimethyl disulfide (DMDS), which hampered the liquid-phase analysis of VOS. Compounds were concentrated from the liquid phase, and automated analyses were performed without additional equipment, other than that required for routine wastewater VOC analysis. The linear range was 5 to 500 microg/L, with r2 > or = 0.99. The average recovery from replicate analyses of spiked samples was 81 +/- 0.5% for methanethiol, 100 +/- 1.5% fordimethyl sulfide (DMS), and 92 +/- 1.5% for DMDS. Method detection limits were 4.8, 2.8, and 1.2 microg/L for methanethiol, DMS, and DMDS, respectively. The relative percent differences were between 0 and 8%.
本文介绍了一种改进方法，用于使用吹扫捕集与气相色谱/质谱联用技术，同时分析废水中的挥发性有机硫化物（VOS）和挥发性有机化合物（VOC）。校准标准品是用经过过滤和氮气吹扫的无VOS废水制备的，将其酸化至pH 1.4。样品也酸化至pH 1.4。这种方法将甲硫醇氧化为二甲基二硫醚（DMDS）的过程减到最少，而DMDS会妨碍VOS的液相分析。化合物从液相中富集，除了常规废水VOC分析所需的设备外，无需额外设备即可进行自动化分析。线性范围为5至500μg/L，r2≥0.99。加标样品重复分析的平均回收率，甲硫醇为81±0.5%，二甲基硫醚（DMS）为100±1.5%，DMDS为92±1.5%。甲硫醇、DMS和DMDS的方法检测限分别为4.8、2.8和1.2μg/L。相对百分差异在0%至8%之间。
