顶空进样-固相微萃取测定饮用水源水中吡啶

Determination of Pyridine in Drinking Source Water by Head Space Sampling-Solid Phase Microextraction

用75μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS)固相微萃取头顶空萃取15 mL水样中的吡啶,萃取物用气相色谱-质谱法进行分离和检测,采用内标法和质谱的选择离子监测模式进行定量分析。优化了顶空进样-固相微萃取条件,获得较佳的萃取温度(58.0℃)和萃取时间(40 min)。在优化的条件下,方法检出限为1.5μg/L,标准曲线的线性相关系数为0.9994,线性范围为2.5～50.0μg/L;饮用水源水和纯水加标平均回收率为75.6%～81.3%,相对标准偏差(RSD,n=6)为9.60%～12.21%。使用顶空萃取方式可避免样品基体的复杂性,有利于保护萃取头涂层,同时无需使用有机萃取溶剂;使用质谱检测器可减小假阳性带来的影响。顶空进样-固相微萃取操作简单、环保、灵敏度高,适合用于饮用水源水中吡啶的监测分析。

Pyridine in 15 mL aqueous sample was micro-extracted by using a head space sampling-solid phase microextration system of 75 μm CarboxenTM-Polydimethylsiloxane（CAR-PDMS） fiber.The extractants were measured by Gas Chromatography-Mass Spectrometry（GC-MS） with selected ion monitoring（SIM） mode and internal standard quantitative method.Under the optimum conditions of an extraction temperature of 58.0℃ for 40 min,detection limit,correlation coefficient and linear range were 1.5 μg/L,0.9994 and 2.5-50.0 μg/L,respectively.The obtained average values of recovery were 75.6%-81.3%（n=6） and the relative standard deviation was 9.60%-12.61% for drinking water samples and pure water with interior spike.Head space sampling-solid phase microextraction（HS-SPME）,an organic solvent-free pre-processing method for water sample,can protect SPME coatings,especially for dirty samples.An MS detector has advantages in qualitative analysis and avoids the fake positive signal effect.Head space-solid phase microextraction is a convenient and sensitive method,which is capable of analyzing pyridine in drinking water.