色谱 ›› 2024, Vol. 42 ›› Issue (9): 856-865.DOI: 10.3724/SP.J.1123.2023.11010

• 研究论文 • 上一篇    下一篇

固相萃取-液相色谱-串联质谱法测定污水中8种新烟碱类农药

王海棠1,2, 李含音1, 陆启伟3, 何士龙1,*()   

  1. 1.中国矿业大学环境与测绘学院,江苏 徐州 221116
    2.江苏省徐州环境监测中心, 江苏 徐州 221000
    3.徐州高新技术产业开发区,江苏 徐州 221000
  • 收稿日期:2023-11-16 出版日期:2024-09-08 发布日期:2024-08-29
  • 通讯作者: *E-mail:hslongrcees@163.com.
  • 基金资助:
    国家重点研发计划项目(2020YFC1908801);江苏省生态环境保护地下水监测监控与污染预警重点实验室开放课题基金项目(GWKL2205)

Determination of eight neonicotinoid pesticides in wastewater by solid phase extraction combined with liquid chromatography-tandem mass spectrometry

WANG Haitang1,2, LI Hanyin1, LU Qiwei3, HE Shilong1,*()   

  1. 1. School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
    2. Xuzhou Environmental Monitoring Center of Jiangsu, Xuzhou 221000, China
    3. Xuzhou High-tech Industrial Development Zone, Xuzhou 221000, China
  • Received:2023-11-16 Online:2024-09-08 Published:2024-08-29
  • Supported by:
    National Key Research and Development Program of China(2020YFC1908801);Key Laboratory of Groundwater Monitoring and Pollution Early Warning of Ecological Environment Protection in Jiangsu Province Open Project Fund(GWKL2205)

摘要:

新烟碱类农药作为一类新型农药,由于其对非靶标生物造成生态风险而引起广泛关注。为了实现污水中痕量新烟碱类农药的快速、准确定量,本研究建立了同时检测污水中8种新烟碱类农药(呋虫胺、E-烯啶虫胺、噻虫嗪、噻虫胺、吡虫啉、氯噻啉、啶虫脒和噻虫啉)的固相萃取-液相色谱-串联质谱法。确定选择色谱流动相类型和质谱参数后,采用单因素法确定固相萃取(SPE)的条件:萃取柱类型为HLB (500 mg/6 mL),上样体积为500 mL,上样速度为10 mL/min,样品pH为6~8。通过优化色谱梯度洗脱程序、样品的稀释倍数并采用同位素内标定量法降低污水样品的基质效应,确定污水稀释5倍进行前处理,采用ZORBAX Eclipse Plus C18色谱柱(100 mm×2.1 mm, 1.8 μm),以含0.1%甲酸的2 mmol/L乙酸铵水溶液和甲醇为流动相进行梯度洗脱,在正离子多反应监测模式下分析10 min,用吡虫啉-d4作为同位素内标进行定量。通过响应曲面法进一步优化SPE的淋洗液及洗脱液类型和用量,确定用10%甲醇水溶液淋洗,7 mL甲醇-乙腈(1∶1, v/v)混合溶液洗脱。8种新烟碱类化合物在相应范围内线性关系良好(线性相关系数(r)均大于0.9990),方法检出限(MDL)为0.2~1.2 ng/L,方法定量限(MQL)为0.8~4.8 ng/L,在低、中、高3个加标水平下的加标回收率为82.6%~94.2%, RSD为3.9%~9.4%。该方法成功用于4个城镇污水处理厂进水水样的分析,8种新烟碱类农药的检出含量为ND~256 ng/L。与类似方法相比,该方法检出限低,准确度高,适用于污水中8种新烟碱类农药的痕量检测。

关键词: 液相色谱-串联质谱, 固相萃取, 新烟碱类农药, 污水, 基质效应, 响应曲面法

Abstract:

Neonicotinoid pesticides are a relatively new class of pesticides that have garnered significant attention owing to their potential ecological risks to nontarget organisms. A method combining solid phase extraction with liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed for the rapid and accurate detection of eight neonicotinoid pesticides (dinotefuran, E-nitenpyram, thiamethoxam, clothianidin, imidacloprid, imidaclothiz, acetamiprid, and thiacloprid) in wastewater. The chromatographic mobile phase and MS parameters were selected, and a single-factor method was used to determine the optimal column type, extraction volume, sample loading speed, and pH for SPE. The optimal parameters were as follows: column type, HLB column (500 mg/6 mL); sample extraction volume, 500 mL; sample loading speed, 10 mL/min; and sample pH, 6-8. The matrix effects of the wastewater samples were reduced by optimizing the chromatographic gradient-elution program, examining the dilution factor of the samples, and using the isotope internal standard calibration method. Prior to analysis, the wastewater samples were diluted 5-fold with ultrapure water for pretreatment. Subsequently, 2 mmol/L ammonium acetate aqueous solution containing 0.1% (v/v) formic acid and methanol was used as mobile phases for gradient elution on a ZORBAX Eclipse Plus C18 column (100 mm×2.1 mm, 1.8 μm). The samples were quantified using positive-ion multiple reaction monitoring (MRM) mode for 10 min. Imidacloprid-d4 was used as the isotope internal standard. The SPE process was further optimized by applying response surface methodology to select the type and mass of rinsing and elution solvents. The optimal pretreatment of the SPE column included rinsing with 10% methanol aqueous solution and elution with methanol-acetonitrile (1∶1, v/v) mixture (7 mL). The eight neonicotinoid pesticides showed satisfactory linearity within the relevant range, with linear correlation coefficients (r) all greater than 0.9990. The method detection limits (MDLs) ranged from 0.2 to 1.2 ng/L, and the method quantification limits (MQLs) ranged from 0.8 to 4.8 ng/L. The average recoveries of the eight neonicotinoid pesticides were in the range of 82.6%-94.2% at three spiked levels, with relative standard deviations (RSDs) ranging from 3.9% to 9.4%. Finally, the optimized method was successfully applied to analyze wastewater samples collected from four sewage treatment plants. The results indicated that the eight neonicotinoid pesticides could be generally detected at concentrations ranging from not detected (ND) to 256 ng/L. The developed method has a low MDL and high accuracy, rendering it a suitable choice for the trace detection of the eight neonicotinoid pesticides in wastewater when compared with other similar methods. The proposed method can be utilized to monitor the environmental impact and assess the potential risks of neonicotinoid pesticides in wastewater, thus promoting the protection of nontarget organisms and the sustainable use of these pesticides in agriculture.

Key words: liquid chromatography-tandem mass spectrometry (LC-MS/MS), solid phase extraction (SPE), neonicotinoid pesticides, wastewater, matrix effect, response surface methodology (RSM)

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