[Determination of organophosphate diesters in facility vegetable soils using ultra-high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry]

Se Pu. 2023 Jan;41(1):58-65. doi: 10.3724/SP.J.1123.2022.05002.
[Article in Chinese]


Organophosphate diesters (Di-OPEs) are biotic or abiotic degradation products of organophosphate esters (OPEs). Current analytical methods focus on detecting Di-OPEs in human urine. Human exposure to Di-OPEs in environmental matrices has not been systematically studied. Soil plays an important role in the environmental migration and transformation of organic pollutants. Previous studies found that OPEs are ubiquitous in soil. However, few studies reported OPEs metabolite pollution in soil, especially in facility vegetable soil. In this study, an ultra-high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry (UPHLC-Orbitrap HRMS) method was developed for the determination of five Di-OPEs (bis(2-chloroethyl) phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCP), di-n-butyl phosphate (DnBP), diphenyl phosphate (DPhP), and bis(2-ethylhexyl) phosphate (DEHP)) in the facility vegetable soil. The pretreatment process and chromatographic and mass spectrometric conditions were optimized in the present study. Comparative study of the purification effects of different solid-phase extraction columns showed that Oasis WAX cartridge had best purification efficiency for the five Di-OPEs. The cartridge was first activated using 3 mL methanol, 3 mL methanol containing 5% (v/v) ammonia, and 3 mL 0.1 mol/L sodium acetate-acetic acid buffer solution. Then, the cartridge was rinsed with 3 mL of 30% (v/v) methanol aqueous solution, and finally eluted using 8 mL methanol containing 5% (v/v) ammonia. The effects of mobile phase (with respect to solvent composition and flow rate) and column temperature on the shape and intensity of chromatographic peaks were studied. The optimized UHPLC conditions were as follows: chromatographic column, Thermo Accucore RP-MS; column temperature, 30 ℃; mobile phase, 0.2 mmol/L ammonium acetate aqueous solution and methanol; flow rate, 0.2 mL/min. In the UHPLC-Orbitrap HRMS experiment, the five Di-OPEs were analyzed in full MS mode with negative ionization. Instrumental parameters, such as sheath gas and auxiliary gas, were optimized to determine the MS conditions. The optimized Orbitrap HRMS conditions were as follows: heating electrospray ionization source (HESI), full MS mode with negative ionization; scan range, m/z 100-500; ion transfer tube temperature, 320 ℃; automatic gain control of target particle count, 1×106; sheath gas flow rate, 8.58 L/min; auxiliary gas flow rate, 17.40 L/min; spray voltage, 3.2 kV; and S-lens voltage, 50 V. The limits of detection and quantification were 0.001-0.047 ng/g and 0.004-0.156 ng/g, respectively. The correlation coefficients of the calibration curve were 0.9985-0.9999. At three spiked levels, 5.0, 25.0, and 50.0 ng/g, the recoveries of the five Di-OPEs ranged from 56.9% to 133.0% with relative standard deviations of 4.4%-18.9%. The established method was applied to the analysis of the five Di-OPEs in 16 facility vegetable soils. The detection frequencies of the five Di-OPEs exceeded 60% in all soil samples, indicating that the Di-OPEs were ubiquitous in the facility vegetable soil. The contents of the five Di-OPEs in the facility vegetable soil samples ranged from 2.53-6.94 ng/g. DnBP (1.37-3.20 ng/g) and DPhP (0.47-2.44 ng/g) were the predominant congeners in the facility vegetable soil samples, accounting for 23.4%-68.8% and 16.3%-35.9% of the five Di-OPEs, respectively. The developed method is simple, sensitive, and reproducible and can be used effectively for the determination of Di-OPEs in soil. The results of this study will be helpful for understanding the environmental behavior of Di-OPEs and their human exposure in facility vegetable soils.

有机磷酸二酯(Di-OPEs)被认为是有机磷酸三酯的生物或非生物降解产物。该研究基于超高效液相色谱-静电场轨道离子阱高分辨质谱(UHPLC-Orbitrap HRMS)建立了设施菜地土壤中磷酸二(2-氯)乙酯(BCEP)、磷酸二(1,3-二氯异丙基)酯(BDCP)、磷酸二正丁酯(DnBP)、磷酸二苯酯(DPhP)和磷酸二(2-乙基己基)酯(DEHP)5种Di-OPEs的定性定量分析方法。首先,土壤样品以甲醇为提取溶剂,超声提取,选择Oasis WAX固相萃取柱进行净化,用8 mL含5% (v/v)氨水的甲醇溶液洗脱,洗脱液浓缩定容后,应用Thermo Accucore RP-MS色谱柱,以甲醇-0.2 mmol/L乙酸铵水溶液为流动相进行分离,采用UHPLC-Orbitrap HRMS测定,质谱分析采用电喷雾负离子模式电离,在全扫描模式下检测。在优化的分析检测条件下,5种Di-OPEs的检出限为0.001~0.047 ng/g,定量限为0.004~0.156 ng/g。5种Di-OPEs的标准曲线线性关系良好,相关系数(r)为0.9985~0.9999。在5.0、25.0、50.0 ng/g的添加条件下,3种加标水平的回收率为56.9%~133.0%,相对标准偏差为4.4%~18.9%。应用建立的方法对采集的16个设施菜地土壤样品进行分析,结果显示设施菜地土壤中5种Di-OPEs的含量为2.53~6.94 ng/g,所有样品中Di-OPEs的检出率均高于60%。其中,DnBP是设施菜地土壤中的主要污染物,含量范围为1.37~3.20 ng/g,占Di-OPEs总含量的23.4%~68.8%。该方法操作简便,灵敏度高,重复性良好,适用于设施菜地土壤中Di-OPEs的测定,也为今后开展设施菜地土壤中Di-OPEs的环境行为和人体暴露研究提供可靠的技术支持。

Keywords: facility vegetable soils; organophosphate diesters (Di-OPEs); ultra-high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Orbitrap HRMS).

Publication types

  • English Abstract

MeSH terms

  • Ammonia
  • Chromatography, High Pressure Liquid
  • Humans
  • Mass Spectrometry
  • Methanol
  • Organophosphates* / urine
  • Phosphates
  • Static Electricity
  • Vegetables*
  • Water


  • Organophosphates
  • Methanol
  • dinoseb
  • Ammonia
  • Phosphates
  • Water