顶空固相微萃取-气相色谱法测定饮用水中的百菌清

Determination of Chlorothalonil in Drinking Water using Headspace Solid Phase Micro-Extraction Coupled with Gas Chromatography

建立了顶空固相微萃取(HS-SPME)-气相色谱法(GC-ECD)分析饮用水中百菌清的方法。对HS-SPME的各项参数进行了优化:萃取纤维应选择弱极性的聚二甲基硅氧烷(PDMS,100μm),水样分析前应加入一定量的H2SO4溶液和Na Cl固体,调节pH和离子强度,可显著提高萃取效率。萃取温度70℃,萃取时间30 min,搅拌速度250 r/min,解吸时间3 min。根据优化后的条件,从线性、检出限、回收率、精密度等方面对整个方法进行了验证,结果表明,该方法线性良好,相关系数大于0.999,回收率与精密度均符合要求。取样量为10.0 mL时,检出限为0.09μg/L,可完全满足饮用水分析的需要。

A method for the detection of chlorothalonil in drinking water using headspace solid phase micro-extraction（HSSPME） combined with gas chromatography（GC） was presented in this paper.The operating conditions of HS-SPME were optimized at first.The best response of chlorothalonil was obtained using 100 μm PDMS.The 10-mL water sample containing 1.0 g sodium chloride and 0.3 mL H2 SO4 solution（0.1 mol/L） was extracted at 70 ℃ and stirred at 250 r/min.The extraction and desorption time was 30 and 3 min,respectively.Under the optimized conditions,correlation coefficient of the standard curve was higher than 0.999.The recoveries and precisions of spiked water samples both met the requirements of quality control.The detection limit was 0.09 μg/L which was adequate to the analysis of chlorothalonil in drinking water.Therefore,this method was easy to operate with high accuracy and good reproducibility.Sample volume could be low to 10.0 mL and organic solvent could also be omitted.