The present study describes the optimization and validation of an analytical method based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and purification with dispersive solid-phase extraction (dSPE) before analysis, followed by ultrahigh-performance liquid chromatography–high-resolution linear ion trap/Orbitrap (LTQ Orbitrap) mass spectrometry for the determination of 18 pesticides in sediment. To optimize process efficiency, parameters such as pH, extraction salts, sediment amount, and cleanup sorbents were evaluated. Identification was based on both accurate mass and retention time, and further confirmation was achieved by mass spectrometry fragmentation. The optimized analytical method demonstrated good validation characteristics, such as accuracy (recoveries from 70.8% to 106.2%), method quantification limits (below 10 ng g^-1 for 89% of the pesticides selected), linearity (coefficient of determination greater than 0.9921 in all cases), precision (repeatability and reproducibility with standard deviations below 18% and 21%, respectively), and matrix effect (signal suppression was exhibited for almost all analytes). The overall method performance, expressed as process efficiency, ranged from 58.8% to 102.1%. The validated method was successfully applied to real samples collected along two rivers in northwestern Greece, revealing the presence of three selected pesticides but at levels below the method quantification limit.

本研究描述了一种分析方法的优化和验证，该方法基于快速，简便，廉价，有效，坚固和安全（QuEChERS）提取和纯化，然后进行分散固相萃取（dSPE）进行分析，然后进行超高性能液体分析色谱-高分辨率线性离子阱/ Orbitrap（LTQ Orbitrap）质谱法测定沉积物中的18种农药。为了优化过程效率，评估了诸如pH值，萃取盐，沉积物量和净化吸附剂等参数。鉴定是基于准确的质量和保留时间，并且通过质谱碎裂可以进一步确认。优化的分析方法显示出良好的验证特征，例如准确度（回收率从70.8％到106.2％），对于所选择的89％的农药为^-1），线性（所有情况下的测定系数均大于0.9921），精度（重复性和重现性（标准偏差分别低于18％和21％））和基质效应（显示出信号抑制作用）几乎所有分析物）。以过程效率表示的总体方法性能为58.8％至102.1％。经验证的方法已成功应用于沿希腊西北部两条河流收集的真实样品，揭示了三种选定农药的存在，但含量低于方法定量限值。