In this study, magnetic molecularly imprinted polymers (MMIPs) were prepared and used as sorbents for extraction of S-phenylmercapturic acid (S-PMA) from urine samples, followed by high-performance liquid chromatography ultraviolet-visible (HPLC-UV/Vis) analysis. The MMIPs were synthesized by the copolymerization reaction of (phenylthio) acetic acid (template molecule), methacrylic acid (functional monomers) and ethylene glycol dimethacrylate (cross-linkers). The morphology, structure property and surface groups of the prepared MMIPs were characterized by scan electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray diffraction pattern, thermogravimetric analyses, Brunauer-Emmett-Teller and vibrating sample magnetometer. The selectivity of the MMIPs was investigated in the presence of interferents. Various parameters affecting the S-PMA extraction efficiency were investigated, including MMIPs amount, pH, sample volume, desorption solvent, as well as extraction and desorption time. The obtained optimal parameters were as follows: MMIPs amount (20 mg), pH (3.0), sample volume (5 mL), desorption solvent (methanol/acetic acid [9/1, v/v]), extraction time (30 minutes) and desorption time (2 minutes). The method was validated according to the Food and Drug Administration Guidance for Industry on Bioanalytical Method Validation. The calibration curve for the analyte was linear in the concentration range of 0.030-1.0 mg/L (r = 0.9995). The LOD and LOQ of the method were 0.0080 and 0.0267 mg/L, respectively. The enrichment factor of the MMIPs was 5. The relative standard deviations of intra- and inter-day tests were in the range of 3.8-5.1% and 3.9-6.3%, respectively. The recoveries at three different concentrations of 0.10, 0.50 and 0.80 mg/L ranged between 95.2% and 98.6%. In addition, the MMIPs could be reused for at least eight times. The proposed method was successfully applied to the determination of S-PMA in urine samples. In addition, this developed method could be used as a tool in the early screening and clinical diagnosis of benzene intoxication.

中文翻译：

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用于从尿液样品中提取 S-苯基硫脲酸的磁性分子印迹聚合物，然后采用高效液相色谱法

在本研究中，制备了磁性分子印迹聚合物 (MMIPs)，并将其用作吸附剂，用于从尿液样品中提取 S-苯基硫脲酸 (S-PMA)，然后采用高效液相色谱紫外-可见 (HPLC-UV/Vis)分析。MMIPs 由（苯硫基）乙酸（模板分子）、甲基丙烯酸（功能单体）和乙二醇二甲基丙烯酸酯（交联剂）的共聚反应合成。通过扫描电子显微镜、透射电子显微镜、红外光谱、X射线衍射图、热重分析、Brunauer-Emmett-Teller和振动样品磁力计对制备的MMIPs的形貌、结构性质和表面基团进行了表征。在干扰物存在的情况下研究了 MMIP 的选择性。研究了影响 S-PMA 提取效率的各种参数，包括 MMIP 量、pH、样品体积、解吸溶剂以及提取和解吸时间。获得的最佳参数如下：MMIPs量（20 mg）、pH（3.0）、样品体积（5 mL）、解吸溶剂（甲醇/乙酸[9/1，v/v]）、提取时间（30分钟） ) 和解吸时间 (2 分钟)。该方法根据食品和药物管理局生物分析方法验证行业指南进行了验证。分析物的校准曲线在 0.030-1.0 mg/L 的浓度范围内呈线性（MMIP 量 (20 mg)、pH (3.0)、样品体积 (5 mL)、解吸溶剂（甲醇/乙酸 [9/1, v/v]）、萃取时间（30 分钟）和解吸时间（2 分钟） . 该方法根据食品和药物管理局生物分析方法验证行业指南进行了验证。分析物的校准曲线在 0.030-1.0 mg/L 的浓度范围内呈线性（MMIP 量 (20 mg)、pH (3.0)、样品体积 (5 mL)、解吸溶剂（甲醇/乙酸 [9/1, v/v]）、萃取时间（30 分钟）和解吸时间（2 分钟） . 该方法根据食品和药物管理局生物分析方法验证行业指南进行了验证。分析物的校准曲线在 0.030-1.0 mg/L 的浓度范围内呈线性（r  = 0.9995)。该方法的 LOD 和 LOQ 分别为 0.0080 和 0.0267 mg/L。MMIPs的富集因子为5。日内和日间测试的相对标准偏差分别在3.8-5.1%和3.9-6.3%的范围内。在 0.10、0.50 和 0.80 mg/L 三种不同浓度下的回收率介于 95.2% 和 98.6% 之间。此外，MMIP 至少可以重复使用八次。该方法成功应用于尿样中 S-PMA 的测定。此外，这种开发的方法可用作苯中毒早期筛查和临床诊断的工具。