Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, India.
J Sci Food Agric. 2022 Mar 30;102(5):1782-1811. doi: 10.1002/jsfa.11515. Epub 2021 Sep 16.
Until now, there is no method available for analysis of pesticide residues in complex matrices like spices. Therefore, there is an urgent need to develop and validate a QuEChERS-based method for the estimation of 104 pesticides in cumin seed.
Samples were spiked for 109 pesticides at concentrations of 0.1, 0.5 and 1.0 mg kg . Of these 104 pesticides were recovered. At 0.1, 0.5 and 0.1 mg kg , recoveries ranged from 71% to 108% when compared with matrix matched standards. Seventeen pesticides showed higher or lower recoveries than acceptable range (70-120%) when quantified using solvent standards showing significant matrix effect (ME) (≥ ±20%) even after 20× dilution. However, for the other pesticides ME was significantly eliminated on dilution. The recovery percentage improved for all pesticides on quantitation with matrix matched standards when compared with solvent standards. For pesticides with lower European Union (EU) maximum residue limits (MRLs), an experiment at lower spiking concentrations of 0.01 and 0.05 mg kg with lower dilutions (8×) reveals that almost all pesticides with lower EU MRLs (0.02 and 0.05 mg kg ) showed recoveries in the range 74-124% and relative standard deviation (RSD) less than 20%.
Theoretical limit of quantitation (LOQ) is proposed which ranged from 0.01 to 0.18 mg kg for matrix matched standards. An LOQ of 0.01 mg kg was easily achieved for the pesticides with lower EU MRLs with lower dilutions (8×) with exception of fipronil for which this can be achieved without dilution provided matrix matched standards are used. The method can be extended to other spices. © 2021 Society of Chemical Industry.
到目前为止，还没有可用于分析像香料这样复杂基质中农药残留的方法。因此，迫切需要开发和验证一种基于 QuEChERS 的方法，用于估计孜然种子中的 104 种农药。
在 0.1、0.5 和 1.0mgkg 浓度下，向样品中添加了 109 种农药。其中 104 种农药被回收。在 0.1、0.5 和 0.1mgkg 时，与基质匹配标准相比，回收率在 71%至 108%之间。当使用溶剂标准定量时，17 种农药的回收率高于或低于可接受范围（70-120%），表明存在显著的基质效应（ME）（≥±20%），即使经过 20 倍稀释后也是如此。然而，对于其他农药，ME 在稀释后显著消除。与溶剂标准相比，使用基质匹配标准进行定量时，所有农药的回收率均有所提高。对于欧盟（EU）最大残留限量（MRL）较低的农药，在较低的添加浓度 0.01 和 0.05mgkg 以及较低的稀释倍数（8 倍）下进行的实验表明，几乎所有 EU MRL 较低的农药（0.02 和 0.05mgkg）的回收率均在 74-124%范围内，相对标准偏差（RSD）小于 20%。
提出了基于基质匹配标准的定量下限（LOQ），范围为 0.01 至 0.18mgkg。对于 EU MRL 较低的农药，使用较低的稀释倍数（8 倍）和较低的添加浓度 0.01mgkg，很容易达到 0.01mgkg 的 LOQ，除了氟虫腈外，使用基质匹配标准时无需稀释即可达到此 LOQ。该方法可扩展到其他香料。© 2021 化学工业协会。
