Rahman Md Musfiqur, Park Jong-Hyouk, Abd El-Aty A M, Choi Jeong-Heui, Bae Hey Ree, Yang Angel, Park Ki Hun, Shim Jae-Han
Natural Products Chemistry Laboratory, Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, Republic of Korea.
Biomed Chromatogr. 2013 Apr;27(4):416-21. doi: 10.1002/bmc.2808. Epub 2012 Sep 17.
A single extraction method was developed for chlorothalonil in shallot using gas chromatography with an electron capture detector (GC-μECD). Samples were extracted with single-step modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method using ethyl acetate as an extraction solvent. Significant matrix effects were observed, and the calibration curve was constructed from the matrix. The linearity of the analytical response across the studied range of concentrations (0.01-1.00 mg/L) was excellent, obtaining a correlation coefficient (r(2) ) of 0.996. >0.996. Recovery studies were carried out on spiked shallot blank samples, at two concentration levels (0.4 and 2.0 mg/kg) with three replicates performed at each level. Mean recoveries of 97.2-104.9% with RSDs of 1.3-2.7% were obtained. The method is demonstrated to be suitable for the determination of chlorothalonil in shallot. The dissipation rates of chlorothalonil were described using first-order kinetics, and its half-life was 2.8 days. Based on the dissipation pattern of the pesticide residues, the pre-harvest residue limit (PHRL) was also calculated. Residues were confirmed via mass spectrometry.
开发了一种使用带电子捕获检测器的气相色谱法（GC-μECD）测定青葱中百菌清的单一提取方法。样品采用单步改良的快速、简便、廉价、高效、耐用且安全（QuEChERS）方法，以乙酸乙酯作为提取溶剂进行提取。观察到显著的基质效应，并从基质构建校准曲线。在所研究的浓度范围（0.01 - 1.00 mg/L）内，分析响应的线性良好，相关系数（r²）为0.996。对加标青葱空白样品进行回收率研究，设置两个浓度水平（0.4和2.0 mg/kg），每个水平进行三次重复。平均回收率为97.2 - 104.9%，相对标准偏差为1.3 - 2.7%。该方法被证明适用于测定青葱中的百菌清。使用一级动力学描述百菌清的消散速率，其半衰期为2.8天。基于农药残留的消散模式，还计算了收获前残留限量（PHRL）。通过质谱对残留进行确证。
