Abstract:

Commonly used household cleaning methods to clean chlorpyrifos in Chinese chive were compared. The effects
of cleaning methods with different cleaning media on chlorpyrifos in Chinese chive were explored. The studies on removal
efficiency of chlorpyrifos in Chinese chive with different cleaning conditions such as various temperatures, time, concentrations
of citric acid, vinegar, sodium carbonate, sodium bicarbonate, salt, cleanser essence and different ultrasonic conditions were
carried out. The results demonstrated that the best methods with removal rate of 49.92% was cleaning twice using water,
which was followed by 40.57% using 3‰ Liby detergent, 39.96% using 3‰ Diao Brand detergent, 36.79% using 1‰ vinegar
solution, 35.35% using 3‰ sodium bicarbonate solution, 34.91% using 40 ℃ water, 33.24% using water at room temperature
for 10 min, 31.24% using 1‰ salt solution, 26.46% using 1‰ sodium carbonate and 1‰ citric acid solution. The optimal
combination was 1‰ vinegar solution, 3‰ sodium carbonate solution and 1‰ salt solution, which could remove more than
80% of the chlorpyrifos in Chinese chive, and result in chlorpyrifos residues less than 0.01 mg/kg and the least loss of vitamin C
and aroma. The cleaning procedure involved cleaning Chinese chive at 40 ℃ water for 10 min twice, and then soaking Chinese
chive in 1‰ vinegar solution, 3‰ sodium carbonate solution, and 1‰ salt solution for 10 min, respectively.

Key words: leek, chlorpyrifos, pesticide residue, removal technology