Abstract:

In order to explore the residues of fungicides, insecticides and acaricides, which are commonly used in fruit and vegetable planting, in composite fruit and vegetable juice, a method for the simultaneous detection of pyraclostrobin, acetamiprid and pyridaben in 3 kinds of composite fruit and vegetable juice by LC-MS/MS was developed. Three composite fruit and vegetable juice made by mixed vegetables and fruits were selected as the materials. The samples were initially extracted by acetonitrile containing 1% (v%) acetic acid, and cleaned up by SPE-NH₂ column. The targets were separated on a C₁₈ column, and detected by LC-MS/MS with ESI positive polarity multiple reactions monitoring (MRM) mode. The matrix-matched external standard calibration curves were used for quantitative analysis. The results showed that: good linear relationship appeared in 5-1000 μg/L of acetamiprid and 1-500 μg/L of pyraclostrobin and pyridaben. The correlation coefficients (R²) were higher than 0.9984. Under three spiked levels of 0.010, 0.10 and 0.50 mg/kg, the recovery rates ranged from 80.6% to 113.4%, and the relative standard deviations (RSD) were 0.5%-9.3%. Limit of quantification (LOQ) of pyraclostrobin, acetamiprid and pyridaben were 0.010 mg/kg, which was the lowest spiked concentration. The method can meet the requirements for the determination of pyraclostrobin, acetamiprid and pyridaben residues in composite fruit and vegetable juice simultaneously, and it is quick, efficient and accurate.

Key words: fruit and vegetable juice, pyraclostrobin, acetamiprid, pyridaben, residue