原位乙酰化-顶空固相微萃取测定水中酚类化合物

Trace Analysis of Phenols and Chlorophenols in Water by in Situ Derivatization Headspace Solid-Phase Microextraction Coupled with Gas Chromatography/Mass Spectrometry

建立了原位乙酰化-顶空固相微萃取-气相色谱/质谱联用测定水中酚类及氯酚类化合物的方法,考察了对衍生化以及萃取过程有影响的相关因素。结果表明,采用65μmPDMS/DVB涂层纤维效果最好。在10mL样品中,搅拌速率600r/min、100μL乙酸酐、0.10gNa2HPO4、4.0gNaCl、60℃时各被测组分检出限在0.014～0.044μg/L之间,相对标准偏差(RSD)≤13.7%,在考察的浓度范围(0.02～25μg/L)内均呈线性变化。实际废水样品测定结果表明,相对标准偏差(9.24%)和回收率(86.4%)符合环境水体中痕量酚类化合物监测的质控要求。

An in situ derivatization headspace solid phase microextraction method has been developed for the determination of phenols and related chlorophenols in water.Acetylated derivatives were selectively determined using gas chromatography/mass spectrometry（GC /MS）.Parameters affecting both derivatization and SPME procedures,such as fiber coating,extraction time,temperature,volume of derivatizating reagent and ionic strength,were studied.Then the polydimethylsiloxane/divinylbenzene fiber（PDMS/DVB,65 μm） was selected.The performance of the method was evaluated in terms of accuracy,linearity,precision and limits of detection.Under the selected conditions,i.e.4.0 g NaCl,0.10 g Na2HPO4 in every 10 mL sample solution,headspace extraction at 60℃ and 600 r/min for 30 min,quantitative recoveries and satisfactory precision（RSD≤13.7%） were obtained.Limits of detection for all target compounds ranged from 0.014 to 0.044 μg/L.Linearity was found in a wide range of concentrations.Finally,the applicability of the proposed method is demonstrated by determining phenols in real wastewater samples.