UPLC-QTOF-MS测定沉积物中7种新型污染物

本研究建立了固相萃取(SPE)-超高效液相色谱-四极杆飞行时间质谱(UPLC-QTOF-MS)检测沉积物中水杨酸(SA)、萘普生(NAX)、布洛芬(IBU)、酮洛芬(KET)、双氯芬酸(DIC)、降固醇酸(CLO)和三氯生(TRI)7种新型污染物的分析方法。样品用甲酸-丙酮溶液(1∶99,V/V)超声提取,MAX阴离子固相萃取柱净化,UPLC-QTOF-MS测定。在优化的实验条件下,7种新型污染物在2~500μg/L浓度范围内线性关系良好,线性相关系数均大于0.99,方法检出限(S/N=3)为0.5~0.6μg/kg,方法定量限(S/N=10)为1.5~2.0μg/kg(均以干重计),3个添加浓度水平(低、中、高)的回收率为87.8%~105.1%,相对标准偏差(n=5)为3.1%~12.2%。利用该方法对广州市流溪河段表层沉积物样品进行分析,检出4种污染物,最高浓度范围为6.51~12.26μg/kg(以干重计)。该方法高效、准确,适用于沉积物中7种污染物的测定。

Determination of Seven New Emerging Pollutants in Sediment Using UPLC-QTOF-MS

A method of ultra-high performance liquid chromatography coupled with quadrupole time-of-flight high resolution mass spectrometry (UPLC-QTOF-MS) was developed for the determination of seven emerging pollutants in sediment, such as salicylic acid, naproxen, ibuprofen, ketoprofen, diclofenac, clofibric acid and triclosan. Sample was extracted with ultrasonic-assisted treatment using the mixture of formic acid-acetone (1∶99,V/V) as extraction solvent, and then purified with solid-phase extraction using a mixed-mode anion exchange (MAX) cartridge, and finally detected by UPLC-QTOF-MS equipped with an electrospray ionization (ESI) source operated in negative mode. Qualitative screening was achieved according to the obtained experimental results with respect to mass accuracy, isotope distribution and relative abundance of the selected ions, i.e, a quasi-molecular ion and a fragment ion for each analyte, and retention time of the corresponding targeted compound. The positive samples, found to contain some/all of the targeted pollutants, were subject to MS/MS scan using the quasi-molecular ions of the analytes as precursor ions, thus generating fragmental ions for further confirmation. Quantification was performed with peak areas of extracted ions within a mass window of 0.05 Da. Satisfactory linearities (R²>0.99) are obtained for all analytes in the concentration range of 2-500 μg/L. Limits of detection (S/N=3) and limits of quantification (S/N=10) are in the range of 0.5-0.6 μg/kg and 1.5-2.0 μg/kg (dry weight (DW)), respectively. Recoveries are 87.8%-105.1% at three spiking levels with relative standard deviations (n=5) from 3.1% to 12.2%. The developed method was applied to the analysis of the investigated compounds in surface sediment samples collected from the Liuxi River in Guangzhou, and 4 pollutants are found with the highest concentration range of 6.51-12.26 μg/kg (DW). This method is efficient, accurate, and suitable for analysis of the seven investigated emerging pollutants in sediments.