水中有机氯农药和氯苯类化合物的顶空固相微萃取-气相色潽测定法

目的 建立同时测定饮用水中有机氯农药和氯苯类化合物的顶空固相微萃取-气相色谱(HS-SPME-GC)法.方法 选择100μm聚二甲基硅氧烷(PDMS)萃取头进行样品的顶空固相微萃取,在1 150 r/min磁搅拌条件下,80℃萃取30min,进样口温度270℃,解吸5 min.柱前压为80 kPa,尾吹气流量为20 ml/min,隔膜清洗气流量为5 ml/min,不分流进样,3 min后再分流,分流比为24:1;ECD检测器温度为300℃.结果 在0.391 2～19.56μg/L范围内,1,4-二氯苯的检出限为8.633ng/L;在0.353 6～17.68μg,L范围内,1,2-二氯苯的检出限为4.023 ng/L;在0.007 7～0.38μg/L范围内,1,3,5-三氯苯的检出限为0.148 ng/L;在0.009 6～0.48μg/L范围内,1,2,4-三氯苯的检出限为0.124 ng/L;在0.007 9～0.39μg/L范围内,1,2,3-三氯苯的检出限为0.099 ng/L;在0.0004～0.02μg/L范围内,六氯苯的检出限为0.005 ng/L;在0.001 0～0.05μg/L范围内,七氯的检出限为0.073 ng/L;在0.096 6～4.83μg/L范围内,百菌清的检出限为0.277 ng/L;在0.008 0～0.40μg/L范围内,α-六六六的检出限为0.013 ng/L;在0.040 0～2.00μg/L范围内,β-六六六的检出限为0.353 ng/L,;在0.008 0～0.40μg/L范围内,γ-六六六的检出限为0.060 ng/L;在0.0400～2.00μg/L范围内,δ-六六六的检出限为1.250 ng/L,;在0.0300～0.10μg/L范围内,p,p'-DDE的检出限为0.030 ng/L;在0.008 0～0.40μg/L范围内,o,p'-DDT的检出限为0.122 ng/L;在0.004 0～0.20μg/L范围内,p,p'-DDD的检出限为0.066 ng/L;在0.020 0～1.00μg/L范围内,p,p'-DDT的检出限为0.464 ng/L.相关系数均在0.99以上.该方法的平均回收率为72.3%～109.0%,RSD为1.8%～11.6%.结论 该方法具有操作简便、快捷,检测限低、不使用有机溶剂等特点,适合于同时测定水中机氯农药和氯苯类化合物.

Determination of Organochlorine Pesticides and Chlorobenzene Compounds in Water by Headspace Solid-Phase Microextraction Combined with Gas Chromatography

Objective To establish a method for determination of organochlorine pesticides and chlorobenzene compounds in water by using headspace solid-phase microextraction (HS-SPME) coupled with GC. Methods 100 μm PDMS was used as SPME fiber. At 1 150 r/min with magnetic stiring,extraction time was 30 min,temperature was 80 ℃. The injector temperature was held at 270 ℃ and desorption time was 5 min. The column pressure was set at 80 kPa. Make-up flow rate was at a constant of 20 ml/min. The septum purge was set at 5 ml/min. The injector was used in splitless mode for 3 min and then in split mode at the rate of 24:1. The ECD system was maintained at 300 ℃. Results The limit of detection (LOD) of 1,4-dichlorobenzene was 8.633 ng/L in the range of 0.39 to 19.56 μg/L. The LOD of 1,2-dichlorobenzene was 4.023 ng/L in 0.35 to 17.68 μg/L. The LOD of 1,3,5-trichlorobenzene was 0.148 ng/L in 0.007 7 to 0.38 μg/L. The LOD of 1,2,4-trichlorobenzene was 0.124 ng/L in 0.009 to 0.48 μg/L. The LOD of 1,2,3-trichlorobenzene was 0.099 ng/L in 0.007 9 to 0.39 μg/L. The LOD of hexachlorobenzene was 0.005 ng/L in 0.000 4 to 0.02 μg/L. The LOD of heptachlor was 0.073 ng/L in 0.001 to 0.05 μg/L. The LOD of chlorothalonil was 0.277 ng/L in 0.096 to 4.83 μg/L. The LOD of α-HCH was 0.013 ng/L in 0.008 to 0.40 μg/L. The LOD of β-HCH was 0.353 ng/L in 0.04 to 2.00 μg/L. The LOD of γ-HCH was 0.06 ng/L in 0.008 to 0.40 μg/L. The LOD of δ-HCH was 1.25 ng/L in 0.04 to 2.00 μg/L. The LOD of p,p'-DDE was 0.03 ng/L in 0.030 to 0.10 μg/L. The LOD of o,p'-DDT was 0.122 ng/L in 0.008 to 0.40 ng/L. The LOD of p,p'-DDD was 0.066 ng/L in 0.004 to 0.20 μg/L. The LOD of p,p'-DDT was 0.464 ng/L in 0.02 to 1.00 μg/L. A good linearity was obtained,r>0.99. The recovery rates were 72.25%-109.0% with the relative standard deviation (RSD) of 1.82% -11.61%. Conclusion The method is fast,simple,sensitive and needs no organic solvent and it is applicable to the determination of organochlorine pesticides and chlorobenzene compounds in water.