Unit Plant Protection Products, DTEVPF, INIA. Crta. La Coruña, Km.7.5, 28040 Madrid, Spain.
Molecules. 2018 Aug 11;23(8):2009. doi: 10.3390/molecules23082009.
Assessment of two buffered QuEChERS (quick, easy, cheap, effective, rugged, and safe) versions (i.e., citrate and acetate) modified by including methanol to recover the residues of three cyclohexanedione oxime (CHD) herbicides and three of their byproducts from agricultural soil was performed. In this context, a full second-order face-centered factorial experimental design was developed to quantify the influences of the main five variables (i.e., extraction time, water content, soil weight, and extraction solvent volume and composition) on the target compound recoveries. The fitting equations satisfactorily described the extraction process behavior. The mathematical models also showed the most influencing independent variables (i.e., extraction solvent composition and soil weight). Handling simpler expressions was possible with the acetate QuEChERS but not with the citrate QuEChERS. The recoveries of the CHD residues were close to 100% after performing the extraction under suitable conditions. Furthermore, dispersive solid-phase extraction (dSPE) clean-up steps were assessed to reduce the matrix effect in mass spectrometry. In this sense, the citrate QuEChERS in combination with the PSA + C18 clean-up step was the best option for the extraction of CHD residues.
评估了两种经甲醇改良的缓冲 QuEChERS（快速、简单、廉价、有效、耐用、安全）版本（即柠檬酸盐和乙酸盐），以从农业土壤中回收三种环己二酮肟（CHD）除草剂及其三种副产物的残留物。在这种情况下，开发了一个完整的二阶中心复合面实验设计，以量化五个主要变量（提取时间、含水量、土壤重量、提取溶剂体积和组成）对目标化合物回收率的影响。拟合方程很好地描述了提取过程的行为。数学模型还表明了最具影响力的独立变量（即提取溶剂组成和土壤重量）。乙酸盐 QuEChERS 可以处理更简单的表达式，但柠檬酸盐 QuEChERS 则不行。在适当的条件下进行提取后，CHD 残留物的回收率接近 100%。此外，还评估了分散固相萃取（dSPE）净化步骤，以降低质谱中的基质效应。在这种情况下，柠檬酸 QuEChERS 与 PSA + C18 净化步骤结合是提取 CHD 残留物的最佳选择。
