环境空气细颗粒物中16种邻苯二甲酸酯类化合物的超高效液相色谱-串联质谱测定法

Ultra high performance liquid chromatography-tandem mass spectrometry determination of 16 phthalate esters in fine particulate matter in ambient air

目的 建立超声波提取-超高效液相色谱-串联质谱法同时检测环境空气细颗粒物(particulate matter,PM_(2.5))中16种邻苯二甲酸酯类化合物(phthalate esters,PAEs)的快速检测方法。方法 使用装有PM_(2.5)切割头的采样器收集样本至石英滤膜上,通过比较不同提取液的提取效率,选择适当的提取液对样品进行超声提取,对比3种色谱柱的分离效果及保留时间,对16种PAEs采用超高效液相色谱-串联质谱法进行检测,内标法定量,得到线性、检出限等指标,加入适量标准至石英滤膜,评价方法的回收率及精密度。结果 16种PAEs类化合物的线性范围在0.5~200 ng/mL的范围内均具有较好的线性关系,R值均>0.995 0;比较50%甲醇水溶液、50%乙腈水溶液、甲醇和乙腈4种提取溶液对加标后浓度为10、50、100μg/L滤膜样品的提取效果,4种提取溶剂的平均加标回收率(n=3)分别为71.45%~126.8%、51.71%~124.40%、68.62%~210.3%和84.08%~110.28%。使用乙腈溶剂进行提取时,3次平行样本的加标回收率最稳定,16种PAEs的加标回收率均在80%~120%之间。使用T3色谱柱时,在15 min内16种PAEs全部分离,分离效果较好。方法精密度≤7.95%,检出限在0.001~0.077 ng/m^(3)之间,加标回收率为83.8%~117.6%。采用本实验方法,对2021年11—12月采集的上海市室外同一采样点不同时期的PM_(2.5)样本(n=9)进行检测,共检出7种邻苯二甲酸酯类化合物,其中5种检出率为100%,分别为邻苯二甲酸二甲酯(dimethyl phthalate,DMP)(0.26~6.39 ng/m^(3))、邻苯二甲酸二乙酯(diethyl phthalate,DEP)(0.96~2.04 ng/m^(3))、邻苯二甲酸二异丁酯(diisobutyl phthalate,DiBP)(9.46~63.40 ng/m^(3))、邻苯二甲酸二丁酯(dibutyl phthalate,DBP)2.52~44.60 ng/m^(3)和邻苯二甲酸二-2-乙基己酯[bis(2-ethylhexyl)phthalate,DEHP](6.29~59.40 ng/m^(3))。结论 该方法的加标回收率稳定,检出限低,准确度和灵敏度高;实验前处理步骤简单,分析时间短,可以用于PM_(2.5)中PAEs的检测。

Objective To establish a rapid detection method for 16 phthalate esters (PAEs) in ambient air fine particulate matter(PM_(2.5)) by ultrasonic extraction ultra high performance liquid chromatography-tandem mass spectrometry.Methods The samples were collected onto a quartz filter membrane by a sampler equipped with the PM_(2.5)cutting head.By comparing the extraction efficiency of different extraction solutions,selecting the appropriate extraction solution for ultrasonic extraction of the sample,comparing the separation effect and retention time of three chromatographic columns,16 types of PAEs were detected using ultra high performance liquid chromatography tandem mass spectrometry,and quantified using internal standard method to obtain indicators such as linearity and detection limit.An appropriate amount of standard was added to the quartz filter membrane to evaluate the recovery rate and precision of the method.Results The linear range of 16 PAEs compounds was within the range of0.5 to 200 ng/mL,and all had good linear relationships,with R>0.995 0.Comparing the extraction effects of 50%methanol aqueous solution,50%acetonitrile aqueous solution,methanol and acetonitrile on the samples with the concentration of10,50,100μg/L after spiked,the average recovery of standard addition (n=3) was 71.45%-126.8%,51.71%-124.40%,68.62%-210.3%and 84.08%-110.28%.When using acetonitrile solvent for extraction,the recovery rates of three parallel samples were the most stable,and the recovery rates of 16 PAEs were all between 80%and 120%.When using T3 chromatographic column,all 16PAEs were separated within 15 minutes,and the separation effect was better.The method precision was≤7.95%,the detection limit was between 0.001 and 0.077 ng/m^(3),and the recovery rate was 83.8%-117.6%.Using this method,PM_(2.5)samples (n=9)collected from the same outdoor sampling point in Shanghai from November to December 2021 at different periods were detected.A total of 7 phthalate ester compounds were detected,of which 5 had a detection rate of 100%,namely dimethyl phthalate (DMP)(0.26-6.39 ng/m^(3)),diethyl phthalate (DEP)(0.96-2.04 ng/m^(3)),and diisobutyl phthalate (DiBP)(9.46-63.40 ng/m^(3)),dibutyl phthalate(DBP)(2.52-44.60 ng/m^(3)) and di-2-ethylhexyl phthalate(DEHP)(6.29-59.40 ng/m^(3)).Conclusion The spiked recovery rate of this method is stable,the detection limit is low,and the accuracy and sensitivity are high.The pre experimental processing steps are simple and the analysis time is short,which can be used for the detection of phthalate esters in PM_(2.5).