A quick and efficient method was optimized and validated to determine chlorpyrifos in biobeds using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Chlorpyrifos was extracted from the matrix with 30 mL of a mixture of acetone, phosphoric acid and water 98:1:1 (v/v/v). After homogenization, centrifugation and filtration, 125 µL of the extract was evaporated and reconstituted in 5 mL of methanol acidified with 0.1% acetic acid. Validation was performed by studying analytical curve linearity (r²), estimated instrument and method limits of detection and limits of quantification (LOD_i, LOD_m, LOQ_i and LOQ_m, respectively), accuracy, precision (expressed as relative standard deviation, RSD), and matrix effect. Accuracy and precision were determined from the amount of pesticide recovered from biobed blank samples (i.e. without pesticide residue) spiked with chlorpyrifos at three different concentrations (2, 10 and 50 mg kg⁻¹), with seven replicates at each concentration. For all three concentrations studied, the average recovery values obtained were between 96 and 115% with RSD values lower than 20%. The validated LOQ obtained was 2 mg kg⁻¹ (from recovery studies) and the matrix effect observed was lower than ±20%, which demonstrated that there was neither considerable suppression nor enhancement of the analyte signal. The biobed system efficiently degraded chlorpyrifos in both 1) simulation of accidental spillage and 2) application of diluted pesticide solution. In the latter case, all the values obtained at the final sampling time (14 months) were below the validated LOQ_m.

使用超高效液相色谱-串联质谱（UPLC-MS / MS），对快速有效的方法进行了优化和验证，以测定生物床上的毒死rif。用30 mL丙酮，磷酸和水98：1：1（v / v / v）的混合物从基质中提取毒死rif。均质，离心和过滤后，将125 µL提取液蒸发，并在5 mL用0.1％乙酸酸化的甲醇中重构。通过研究分析曲线线性度（r ²），估计的仪器和方法的检测极限以及定量极限（LOD _i，LOD _m，LOQ _i和LOQ _{m）进行验证。}，精度，精度（表示为相对标准偏差，RSD）和矩阵效应。根据从生物床空白样品（即无农药残留物）中加有毒死rif的三种不同浓度（2、10和50 mg kg ^-1）加标的农药量来确定准确性和精密度，每种浓度重复七次。对于所研究的所有三个浓度，获得的平均回收率在96％至115％之间，RSD值低于20％。获得的确认的最低定量为2 mg kg ^-1（来自回收率研究），观察到的基质效应低于±20％，这表明分析物信号既没有明显的抑制也没有增强。在1）意外泄漏的模拟和2）稀释农药溶液的施用中，生物床系统可有效降解毒死rif。在后一种情况下，在最终采样时间（14个月）获得的所有值均低于验证的LOQ _m。