Abdel-Ghany Maha F, Hussein Lobna A, El Azab Noha F
Ain Shams University, Faculty of Pharmacy, Pharmaceutical Analytical Chemistry Department, Cairo, Egypt.
J AOAC Int. 2017 Jan 1;100(1):176-188. doi: 10.5740/jaoacint.16-0162. Epub 2016 Oct 19.
A sensitive, selective, and validated HPLC-diode-array detection method was developed for the simultaneous determination of five neonicotinoid insecticides-acetamiprid, imidacloprid, nitenpyram, flonicamid, and thiacloprid-and their primary metabolite, 6-chloronicotinic acid, in cucumbers and soil based on the quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique as a pretreatment procedure. In the QuEChERS procedure, cucumber samples were extracted with acetonitrile and cleaned using C18, whereas soil samples were extracted with an acetonitrile-dichloromethane mixture (1 + 2). The HPLC conditions were optimized by separating neonicotinoids using an acetonitrile-water mixture (25 + 75) and a Synergi Hydro RP C18 column. Matrix-matched calibration standards were prepared in cucumber and soil to eliminate any matrix interference. RSDs were ≤9% in all recovery tests. LODs and LOQs for the five neonicotinoids were in the ranges of 0.006-0.122 and 0.018-0.366 μg/g, respectively. This method was successfully applied to determine residues, the rate of disappearance of the five neonicotinoids from cucumber and soil, and the half-lives of the neonicotinoids.
基于快速、简便、廉价、高效、耐用且安全（QuEChERS）技术作为预处理程序，开发了一种灵敏、选择性强且经过验证的高效液相色谱-二极管阵列检测方法，用于同时测定黄瓜和土壤中的五种新烟碱类杀虫剂——啶虫脒、吡虫啉、烯啶虫胺、氟啶虫酰胺和噻虫啉——及其主要代谢物6-氯烟酸。在QuEChERS程序中，黄瓜样品用乙腈提取并用C18净化，而土壤样品用乙腈-二氯甲烷混合物（1 + 2）提取。通过使用乙腈-水混合物（25 + 75）和Synergi Hydro RP C18柱分离新烟碱类化合物来优化高效液相色谱条件。在黄瓜和土壤中制备基质匹配校准标准品以消除任何基质干扰。所有回收率测试中的相对标准偏差均≤9%。五种新烟碱类化合物的检测限和定量限分别在0.006 - 0.122和0.018 - 0.366 μg/g范围内。该方法成功应用于测定黄瓜和土壤中五种新烟碱类化合物的残留量、消失速率以及半衰期。
