色谱 ›› 2021, Vol. 39 ›› Issue (5): 510-517.DOI: 10.3724/SP.J.1123.2020.07006

• 研究论文 • 上一篇    下一篇

液液萃取-气相色谱-质谱法同时测定水中46种半挥发性有机物

刘玲玲, 张利钧, 董希良, 陈晓梅, 赵传明*()   

  1. 济南市环境研究院, 山东 济南 250100
  • 收稿日期:2020-07-05 出版日期:2021-05-08 发布日期:2021-03-31
  • 通讯作者: 赵传明
  • 作者简介:Tel:(0531)66626160,E-mail:zhaochuanming@jnep.cn.
  • 基金资助:
    国家自然科学基金(41807111)

Simultaneous determination of 46 semi-volatile organic compounds in water by liquid-liquid extraction-gas chromatography-mass spectrometry

LIU Lingling, ZHANG Lijun, DONG Xiliang, CHEN Xiaomei, ZHAO Chuanming*()   

  1. Jinan Environmental Research Institute, Jinan 250100, China
  • Received:2020-07-05 Online:2021-05-08 Published:2021-03-31
  • Contact: ZHAO Chuanming
  • Supported by:
    National Natural Science Foundation of China(41807111)

摘要:

半挥发性有机物主要包括多环芳烃类(PAHs)、邻苯二甲酸酯类(PAEs)、有机氯农药类(OCPs)和硝基苯类(NBs)等化合物,这些物质多具有致癌、致畸、致突变作用,以及内分泌干扰效应。因此,快速准确测定水中半挥发性有机物非常重要,目前国内尚无水中半挥发性有机物的检测标准。该研究从氮吹温度、水样pH值和萃取时间3个方面进行了优化,旨在建立一种液液萃取-气相色谱-质谱(LLE-GC-MS)同时测定水中46种半挥发性有机物的方法。结果表明:氮吹温度对46种半挥发性有机物的回收率影响不大,考虑回收率及浓缩效率,将氮吹温度设定为35 ℃;水样在中性环境下萃取效果好于碱性环境下的效果;萃取时间由7 min增加至10 min时,回收率也随之提高,但时间增加至15 min时,17种(占比37%)化合物回收率有所增加,29种(占比63%)化合物回收率则呈降低趋势。因此,将萃取时间设定为每次10 min。采用气相色谱-质谱仪进行检测,内标法定量。该方法在20.0~2000 μg/L范围内线性良好,相关系数(r 2)≥0.9916, 46种SVOCs检出限为0.28~16.55 ng/L,定量限为0.92~55.16 ng/L;在0.02、0.2、0.4 μg/L 3个加标水平下的平均回收率为63.6%~125%,相对标准偏差(n=6)为1.03%~17.0%。采用该方法检测了黄河流域济南段的27个地表水样品,检出的物质以PAEs和PAHs为主,2种OCPs在部分点位有检出,NBs均未检出。该方法操作简单,通用性强,准确度及精密度良好,检出限低,适用于地表水及地下水中46种半挥发性有机物的同时检测。

关键词: 气相色谱-质谱, 液液萃取, 半挥发性有机物

Abstract:

Semi-volatile organic compounds (SVOCs) include polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), organochlorine pesticides (OCPs) and nitrobenzenes (NBs). Most of them have carcinogenic, teratogenic, mutagenic and endocrine disrupting effects. Therefore, rapid and accurate determination of SVOCs in water is very important. As the most traditional pretreatment method, liquid-liquid extraction (LLE) has the advantages of wide extraction range, high extraction efficiency, simple operation and lower cost, which is very suitable for the simultaneous extraction of multiclass SVOCs. Dichloromethane has good solubility for most SVOCs, and is slightly soluble in water with low boiling point. It is a good broad-spectrum extractive solvent of organic compounds. But at present, there is no detection standard of SVOCs in water in China. In this study, three factors including nitrogen blowing temperature, pH of water sample and extraction time were optimized. It was aimed to establish a liquid-liquid extraction-gas chromatography-mass spectrometry (GC-MS) method for the simultaneous determination of the 46 SVOCs in water. At first, the effect of nitrogen blowing temperature (30, 35, 40 ℃) was investigated. The results showed that under different nitrogen blowing temperature, the recoveries of the 46 SVOCs were slightly different, but the differences were not significant. Considering the recovery and concentration efficiency, the nitrogen blowing temperature was finally set at 35 ℃. Dichloromethane was selected as the LLE solvent of the SVOCs and its extraction efficiency was investigated. The recoveries of the 46 SVOCs were satisfactory for the determination. Then sample pH (neutral and alkaline condition) was investigated. Most of the SVOCs in this paper have no obvious acid-base property. The extraction effect of water sample under neutral conditions was the best and the most stable, and under alkaline condition, the recovery of each substance was generally low. Finally, extraction time (7, 10, 15 min) was studied. In a certain range, with the increase of extraction time, the recovery also increased, but when the time increased to 15 min, the recovery of some compounds increased or decreased, and the time-consuming was longer, the recovery of most substances could meet the requirements when the extraction time was set to 10 min. The optimized experimental conditions were determined as follows: under neutral conditions, the water sample was extracted by dichloromethane for three times, each extraction time was 10 min, and concentrated at the nitrogen blowing temperature of 35 ℃. GC-MS was used for detection, and internal standard method was used for quantitative analysis. The results showed that the linearity of the method was good in the range of 20-2000 μg/L, the correlation coefficients (r 2) were no less than 0.9916, the limits of detection (LODs, S/N=3) ranged from 0.28 to 16.55 ng/L, and the limits of quantification (LOQs, S/N=10) ranged from 0.92 to 55.16 ng/L. The average recovery was 63.6%-125% at three spiked levels of 0.02, 0.2, 0.4 μg/L, with the relative standard deviations (n=6) ranging from 1.03% to 17.0%. This method was applied for the determination of 27 surface water samples in Jinan section of the Yellow River. The pollutants were mainly PAEs and PAHs, while NBs were not detected, only two kinds of OCPs were detected at some sites. The method is simple, universal, accurate and precise, and has low detection limit. It is suitable for the simultaneous determination of the 46 SVOCs in surface water and groundwater.

Key words: gas chromatography-mass spectrometry (GC-MS), liquid-liquid extraction (LLE), semi-volatile organic compounds (SVOCs)

中图分类号: