吹扫捕集-气相色谱联用同时测定水中致嗅挥发性有机硫化物

摘要

A method for simultaneous determination of 16 odor volatile organic sulfur compounds ( VOSC) in water sample was developed with purge and trap ( P&T) , followed by gas chromatography ( GC)-flame photometric detector ( FPD) . The various parameters including trap type, purge temperature, purge time, desorb temperature and desorb time, were investigated for optimization of P&T performance. The experimental results showed that the linear dynamic ranges were 1-100 ng/L and 3-300 g/L for sulfides and thiols respectively, with correlation coefficients greater than 0.99. The relative standard deviation ( RSD) were all below 9.47% (n=6). The detection limits (10 S/N) ranged from 0.19 ng/L for diethyl disulfide (DEDS) to 2.67 ng/L for 2-methy-2-propanethiol (2-Me-2-PrSH). The method was applied to the determination of VOSC in three rivers around Beijing. Except 1-propyl disulfide ( 1-PrDS ) and 2-methyl-2-propanethiol ( 2-Me-2-PrSH ) , other 14 kinds of organic sulfides were detected, with the concentration range from 1.95 to 1 282.35 ng/L.%建立了一种利用吹扫捕集（ P＆T）-气相色谱（ GC）/火焰光度检测器（ FPD）同时测定水中16种致嗅类有机硫化物的分析方法。研究并优化了捕集阱类型、吹扫温度、吹扫时间，解吸温度以及解吸时间对P＆T的影响。实验表明：大部分硫醚类和硫醇类化合物分别在1～100 ng/L和3～300 ng/L范围内线性良好，线性相关系数大于0.99；相对标准偏差小于9.47％（n＝6）；加标回收率为81.68％～115.18％。定量下限（10倍信噪比）范围从0.19 ng/L（二乙基二硫醚）到2.67 ng/L（2-甲基-1-丙硫醇）。采用此方法对北京市3条河流水样进行了检测，除1-丙基二硫醚和2-甲基-2-丙硫醇外，其他14种有机硫化物都有检出，质量浓度为1.95～1282.35 ng/L。