Bisphenols (BPs) and parabens (PBs) are of great concern for environmental pollution and human health because of their endocrine-disrupting effects and potential health hazards. Urinary biomonitoring of BPs and PBs can provide basic data for human internal exposure evaluation, which is a prerequisite for accurately assessing their health risks. In this study, we developed a new pretreatment procedure based on solid supported liquid-liquid extraction (SLE) for the simultaneous separation of ten BPs and five PBs in human urine, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. In the instrumental analysis, the HPLC conditions and MS/MS parameters were comprehensively optimized. Accurate qualitative and quantitative determination of ten BPs and five PBs was achieved by introducing a ternary gradient elution system of water, methanol, and acetonitrile for LC separation. During sample pretreatment, the extraction solvent and elution volume were optimized. Specifically, urine samples were held at room temperature and centrifuged at 3000 r/min for 10 min. The supernatant (2 mL) was then transferred to a glass tube, and the pH was adjusted to 5.0 using HCl (0.5 mL; 0.1 mol/L) and NaAc-HAc buffer (1.5 mL). Thereafter, β-glucuronidase-arylsulfatase (20 μL) and surrogate standard solutions (10 ng;13C12-BPS,13C12-BPAF,13C6-MeP, and 13C6-BuP) were added, and the mixture was incubated in a shaker bath in the dark at 37 ℃ for 16 h. After incubation, the hydrolyzed sample (4 mL) was loaded onto an SLE cartridge and equilibrated for a minimum of 5 min to ensure the solution was completely absorbed by the packing material. Subsequently, the target chemicals were eluted with a mixed ethyl acetate/n-hexane solution (3∶7, v/v; 15 mL). Separation of the targets was performed on a ZORBAX SB-C18 reversed-phase column (250 mm×4.6 mm, 5 μm) using an acetonitrile-methanol-water system as the mobile phase. The method was verified by spiking mixed urine samples at three levels (1, 5, and 50 μg/L), with the recoveries ranging from 84.3% to 119.8%. Except for bisphenols (BPS), whose matrix effect was calculated as -21.8%, the matrix effects of other analytes were lower than 20%, indicating low matrix interference. The linear ranges of the analytes varied from 0.1-500 μg/L to 1-500 μg/L, with correlation coefficients higher than 0.995. The method limits of quantification for target chemicals ranged from 0.03 to 0.30 μg/L, and the relative standard deviations of intra- and inter-day experiments were 1.4%-8.4% and 5.7%-14.6%, respectively, suggesting high stability and reproducibility. The method was successfully applied to the determination of ten BPs and five PBs in 10 urine samples from a general population. The concentrations of target chemicals in the human urine samples varied. Methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and bisphenol A (BPA) were detected in all samples, with median mass concentrations of 1.10, 0.60, 0.21, and 0.55 μg/L, respectively. The detection rates of the other chemicals were less than 50%, which may be related to the production and use of specific chemicals, their bioavailability, and biological metabolism in humans.
尿液中双酚类化合物(BPs)和对羟基苯甲酸酯类化合物(PBs)的浓度水平监测为考察其在人体内的暴露提供基础数据,是准确评估其健康风险的前提。本研究使用基于固相支撑液液萃取(SLE)原理的新型萃取柱,建立了新的BPs和PBs快速前处理技术,在此基础上利用液相色谱-串联质谱法(LC-MS/MS)同时测定人体尿液中10种BPs和5种PBs。尿样先酶解,然后经SLE柱富集,使用15 mL乙酸乙酯-正己烷(3∶7, v/v)混合溶液进行洗脱;通过引进水、甲醇和乙腈的三元流动相梯度洗脱系统,实现了15种目标化合物的准确定性和定量分析。在混合尿液基质中,低、中、高3个水平的加标回收率为84.3%~119.8%;除双酚S外,其余14种化合物的基质效应均在20%以下,表明具有良好的回收率和较低的生物基质干扰。15种目标化合物在各自的线性范围内线性关系良好,相关系数均大于0.995;方法定量限为0.03~0.30 μg/L;精密度测试结果显示,日内和日间连续进样仪器响应的相对标准偏差分别为1.4%~8.4%和5.7%~14.6%,证明具有良好的稳定性和重复性。该方法成功应用于10个普通人群尿样中10种BPs和5种PBs的测定。结果表明,检出率最高的化合物为MeP、EtP、PrP和BPA,其中值质量浓度分别为1.10、0.60、0.21和0.55 μg/L,其余化合物检出率低于50%,这可能与化合物的生产使用量、生物可利用性以及在人体内的生物代谢能力相关。
Keywords: bisphenols (BPs); liquid chromatography-tandem mass spectrometry (LC-MS/MS); parabens (PBs); solid supported liquid-liquid extraction (SLE); urine.