Aromatic amines are a class of compounds bearing amino groups on their benzene rings; these compounds are important raw materials for the industrial production of rubber chemicals, pesticides, dyes, pharmaceuticals, photosensitive chemicals, and agricultural chemicals. Research has revealed that some aromatic amines teratogenetic, carcinogenic, and mutagenic properties. Given the high toxicity and potential harm caused by aromatic amines, monitoring their levels in water sources is critical. Aromatic amines are among the 14 strategic environmental pollutants blacklisted in China, and assessing their exposure levels is essential for protecting human health and the environment. At present, the standard method for detecting aromatic amines in water is liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS). However, this method has the disadvantages of large sample size requirement, complex operation, long analysis time, and high reagent consumption. In this study, instead of traditional LLE technology, cloud point extraction (CPE) technology was used in combination with GC-MS to establish an efficient, sensitive, and environment-friendly method for the detection of nine aromatic amines, namely, 2-chloramine, 3-chloramine, 4-chloramine, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 1-naphthylamine, 2-naphthylamine, and 4-aminobenzene, in water. Triton X-114 was used as the extraction agent. The main experimental parameters were optimized using a single-factor optimization method. The aromatic amines in various water samples were quantitatively analyzed using GC-MS. The nine aromatic amines were separated on a DB-35 MS capillary column (30 m×0.25 mm×0.25 μm). The mass spectrometer was operated in selected ion monitoring (SIM) mode, and quantitative analysis was performed using the internal standard method. The results demonstrated that all nine aromatic amines could be completely separated within 16 min and had good linearities within accurate mass concentration ranges, with correlation coefficients (R2) greater than 0.998. The limits of detection (LODs) and quantification (LOQs) of these aromatic amines in water were 0.12-0.48 and 0.40-1.60 μg/L, respectively. The accuracy and precision of the method were assessed via the determination of aromatic amines in surface water of drinking water sources, offshore seawater, wastewater of the typical printing and dyeing industry at levels of 2.0 and 10.0 μg/L. The recoveries of the aromatic amines in surface water of drinking water sources were 81.1%-109.8%, with intra-day and inter-day relative standard deviations (RSDs) of 0.7%-5.2% (n=6) and 1.6%-6.2% (n=3), respectively. The recoveries of the aromatic amines in offshore seawater were 83.0%-115.8%, with intra-day RSDs (n=6) of 1.5%-8.6% and inter-day RSDs (n=3) of 2.4%-12.2%. The recoveries of the nine aromatic amines in wastewater of the typical printing and dyeing industry were 91.0%-120.0%, with intra-day RSDs (n=6) of 2.9%-12.9% and inter-day RSDs (n=3) of 2.5%-13.1%. The established method was used to detect nine aromatic amines in actual water samples. No aromatic amines were detected in the surface water of drinking water sources or offshore seawater samples. However, 2-chloramine, 4-chloramine, and 4-aminobenzene, which are frequently used in the printing and dyeing industry, were detected in the wastewater of the typical printing and dyeing industry samples. The proposed method offers the advantages of simple operation, high sensitivity, low cost, low organic reagent requirement, and good repeatability. Thus, this method provides reliable technical support for studying the residual status and environmental behavior of aromatic amines in water.
本研究基于以曲拉通X-114(Triton X-114)为萃取剂的浊点萃取技术和气相色谱-质谱法,建立了一种高效、高灵敏度的水体中9种芳香胺(2-氯胺、3-氯胺、4-氯胺、2-硝基苯胺、3-硝基苯胺、4-硝基苯胺、1-萘胺、2-萘胺和4-氨基联苯)的检测方法。采用单因素优化法对影响提取效果的重要因素进行了优化。采用气相色谱-质谱对水中9种芳香胺进行定性、定量分析,使用中等极性色谱柱DB-35 MS(30 m×0.25 mm×0.25 μm)进行分离,在选择离子模式(SIM)下测定,内标法定量。实验结果表明,9种芳香胺在16 min内能够完全分离,且在各自的范围内线性关系良好,相关系数(R2)均大于0.998。9种芳香胺的检出限(LOD)和定量限(LOQ)分别为0.12~0.48 μg/L和0.40~1.60 μg/L。选取饮用水源地地表水、近海海水和典型印染行业废水3种类型水体进行加标回收试验,在2个加标水平(2.0、10.0 μg/L)下,饮用水源地地表水的加标回收率为81.1%~109.8%,日内精密度为0.7%~5.2%,日间精密度为1.6%~6.2%;近海海水的加标回收率为83.0%~115.8%,日内精密度为1.5%~8.6%,日间精密度为2.4%~12.2%;典型印染行业废水的加标回收率为91.0%~120.0%,日内精密度为2.9%~12.9%,日间精密度为2.5%~13.1%。采用所建立方法对饮用水源地地表水、近海海水和典型印染行业废水中的9种芳香胺进行检测,在饮用水源地地表水和近海海水中均未检出目标组分,而在印染行业废水中主要检出2-氯胺、4-氯胺和4-氨基联苯3种印染行业常用的芳香胺。与其他方法相比,该方法具有操作简单、灵敏度高、成本低、有机试剂用量少、重复性较好等优点,为水中芳香胺及其他痕量有机物的测定提供了技术支持。
Keywords: aromatic amines; cloud point extraction (CPE); environmental water sample; gas chromatography-mass spectrometry (GC-MS).