顶空固相微萃取-气相色谱法测定水中16种有机氯农药的含量

GC Determination of 16 Organochlorine Pesticides in Water with Headspace Solid Phase Microextraction

取水样(8.00 mL)置于20 mL顶空瓶中,加入3 g氯化钠至饱和。采用聚二甲基硅氧烷/二乙烯基苯(PDMS/DVB)萃取纤维头,在振动速率250 r·min-1下于70℃萃取60 min。萃取后将PDMS/DVB萃取纤维头插入气相色谱仪,解吸4 min,采用HP-5色谱柱为固定相进行色谱分离。16种有机氯农药的质量浓度在一定范围内与其峰面积呈线性关系,检出限(3.143s)为0.001~0.005μg·L-1。按标准加入法进行回收试验,回收率在70.6%~132%之间,测定值的相对标准偏差(n=6)在3.7%~30%之间。利用上述方法开展了水中有机氯农药的保存试验研究。

Water sample （8. 00 mL） was placed in 20 mL headspace flask and saturated with 3 g of sodium chloride. The solution was extracted for 60 rain at 70 ℃ at a vibration rate of 250 r · min^-1 , using the extract fiber of poly （dimethylsiloxane）/ divinylbenzene （PDMS/DVB）. After extraction, the PDMS/DVB extract fiber was inserted into GC and desorbed for 4 miru The extract was separated by GC using HP-5 chromatographic column as stationary phase. Linear relationships between values of peak area and mass concentration of 16 organochlorine pesticides were found in definite ranges, with detection limits （3. 143s） in the range of 0. 001-0. 005μg·L^-1. Test for recovery was made by standard addition method, giving results in the range of 70. 6 %-132 %, with RSDs （n=6） ranged from 3.7% to 30%. The preservation of organochlorine pesticides in water was studied by the above method.