Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, P. R. China.
J Agric Food Chem. 2021 Jan 20;69(2):756-766. doi: 10.1021/acs.jafc.0c02081. Epub 2021 Jan 6.
An effective and sensitive method for the determination of isopyrazam (IZM) isomers (-IZM and -IZM) and their metabolites (545364 and 545449) in tomato and soil by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed in the present study. The method showed excellent linearities ( = 0.999) at 0.005-5 mg/L. The recoveries were 92.0-107%, and the relative standard deviation (RSD) values were lower than 9.40% in tomato and soil matrices at 0.01, 0.1, and 10 mg/kg. The limits of detection (LODs) of the four compounds ranged from 6.88 × 10 to 2.70 × 10 mg/kg, while the limits of quantification (LOQs) ranged from 2.20 × 10 to 9.20 × 10 mg/kg. The storage stability test results showed that -IZM, -IZM, 545449, and 545364 were stable in tomato at -20 °C within 36 weeks, and the maximum degradation rates were 16.0, 12.0, 7.10, and 12.0%, respectively. The field dissipation test results showed that the half-lives of -IZM in tomato and soil were 2.60-10.2 and 13.6-33.0 days, respectively, while the half-lives of -IZM in soil were 21.7-46.2 days, and no residues of -IZM were detected in tomato. The terminal residue test results showed that the residue of -IZM and -IZM in tomato ranged from <0.0100-0.490 to <0.0100-0.0850 mg/kg. The present results showed that -IZM degraded faster than -IZM in tomato and soil, and had a lower residue level in tomato.
本研究建立了超高效液相色谱-串联质谱法（UPLC-MS/MS）测定番茄和土壤中异吡唑胺（IZM）对映异构体（-IZM 和 -IZM）及其代谢物（545364 和 545449）的方法。该方法在 0.005-5 mg/L 范围内具有良好的线性关系（r=0.999）。在 0.01、0.1 和 10 mg/kg 时，番茄和土壤基质中的回收率为 92.0%-107%，相对标准偏差（RSD）值均低于 9.40%。四种化合物的检出限（LOD）范围为 6.88×10-2.70×10 mg/kg，定量限（LOQ）范围为 2.20×10-9.20×10 mg/kg。储存稳定性试验结果表明，-IZM、-IZM、545449 和 545364 在-20°C下于番茄中可稳定保存 36 周，最大降解率分别为 16.0%、12.0%、7.10%和 12.0%。田间消解试验结果表明，-IZM 在番茄和土壤中的半衰期分别为 2.60-10.2 和 13.6-33.0 天，-IZM 在土壤中的半衰期为 21.7-46.2 天，番茄中未检出 -IZM 残留。最终残留试验结果表明，-IZM 和 -IZM 在番茄中的残留量范围为<0.0100-0.490 至 <0.0100-0.0850 mg/kg。结果表明，-IZM 在番茄和土壤中的降解速度快于 -IZM，在番茄中的残留水平较低。
