Uncertainty evaluation for determination of isocarbophos residues in tea by QuEChERS-gas chromatography-tandem mass spectrometry

Abstract

Objective: The uncertainty of determination of Isocarbophos residues in tea by using QuEChERS-gas chromatography-tandem mass spectrometry techniqne was evaluated. Methods: Isocarbophos residues in tea was determined by using "GB 23200.113—2018 National food safety Standard-Determination of 208 pesticides and metabolites residues in plant origin-Gas chromatography-tandem mass spectrometry method", and factors in the determination of isocarbophos were analyzed by establishing a mathematical model, including sample weighing, volume, calibration of standard solutions, repeatability and recovery rate, etc.. Results: When the residual amount of isocarbophos in tea was 0.050 mg/kg, the expanded uncertainty was 0.007 mg/kg, and the determination result was expressed as: ω=（0.050±0.007） mg/kg, k=2. Conclusion: The main sources of uncertainty in this method werecalibration of standard solutions and the recovery rate.

Keywords

• isocarbophos
• tea
• quechers-gas chromatography-tandem mass spectrometry
• uncertainty