Determination of pyraclostrobin in ginseng samples by molecularly imprinted dispersive solid-phase extraction (MIDSPE) coupled with high-performance liquid chromatography (HPLC) method was developed. Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using pyraclostrobin as template, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile (AIBN) as cross-linker and initiator, respectively. The mixture of butanone (MEK) and n-heptane (7:3, V:V) was used as solvent and porogen. The microspheres were characterized by laser particle size analyzer, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). Binding experiments showed high binding capacity of polymers, and that the maximum adsorption of MIPs and NIPs to pyraclostrobin was 73.01 mg g⁻¹ and 59.14 mg g⁻¹. Selective adsorption experiments verified that polymers had specific and selective recognition site for pyraclostrobin. Comparing MIPs with C₁₈, the recoveries of pyraclostrobin from blank ginseng samples spiked at 0.05, 0.1, and 1.0 mg kg⁻¹ ranged between 77.6% and 93.5% with the standard deviation of 2.18–6.07 and the relative standard deviations (RSDs) between 2.47 and 6.99% (n = 5). The recoveries of pyraclostrobin that used C₁₈ as sorbent were found to be 53.04–63.86% with the standard deviation of 1.13–2.83 and the relative standard deviations of 1.07–4.99%. The data indicated that the method for the analysis of the pyraclostrobin in ginseng samples can achieve good recoveries, repeatability and reproducibility. The linear regression equation was calculated as y = 2.09935e−006x + 0.0176235 (R² = 0.998656). The limit of detection (LOD, S/N = 3) was 0.01 mg kg⁻¹. The confidence interval for the slope at the 95% confidence level was [356084.1828, 899542.8563], and the confidence interval for the intercept was [− 755349.2710, 72645.0856]. The MIDSPE-HPLC method showed specific selective separation and enrichment of trace pyraclostrobin in ginseng samples. The raw samples were tested and results were all below the maximum Residue Limit (MRL) 0.1 mg kg⁻¹ in the European Union.

中文翻译：

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分子印迹分散固相萃取-高效液相色谱法测定人参中的吡菌酯

建立了分子印迹分散固相萃取（MIDSPE）结合高效液相色谱（HPLC）方法测定人参样品中吡咯菌酯的方法。分子印迹聚合物（MIPs）是通过沉淀聚合反应制备的，分别使用吡咯菌酯作为模板，甲基丙烯酸（MAA）作为功能性单体，乙二醇二甲基丙烯酸酯（EGDMA）和偶氮二异丁腈（AIBN）作为交联剂和引发剂。丁酮（MEK）和n的混合物-庚烷（7∶3，V∶V）用作溶剂和成孔剂。通过激光粒度分析仪，扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）对微球进行了表征。结合实验显示出聚合物的高结合能力，并且MIP和NIP对吡菌胺酯的最大吸附为73.01 mg g ^-1和59.14 mg g ^-1。选择性吸附实验证实了聚合物具有吡咯菌酯的特异性和选择性识别位点。将MIP与C ₁₈进行比较，空白人参样品中的吡菌胺酯的回收率分别为0.05、0.1和1.0 mg kg ^-1范围在77.6％和93.5％之间，标准偏差为2.18–6.07，相对标准偏差（RSD）在2.47和6.99％之间（n  = 5）。使用C ₁₈作为吸附剂的吡咯菌酯的回收率为53.04–63.86％，标准偏差为1.13–2.83，相对标准偏差为1.07–4.99％。数据表明，人参样品中吡咯菌酯的分析方法可实现良好的回收率，可重复性和重现性。线性回归方程计算为y  = 2.09935e-006 x  + 0.0176235（R ²  = 0.998656）。检出限（LOD，S / N  = 3）为0.01 mg kg ^-1。斜率在95％置信度下的置信区间为[356084.1828，899542.8563]，截距的置信区间为[-755349.2710，72645.0856]。MIDSPE-HPLC方法显示了人参样品中痕量吡咯菌酯的特异性选择性分离和富集。对原始样品进行了测试，结果均低于欧盟规定的最大残留限量（MRL）0.1 mg kg ^-1。