Determination of herbicide clopyralid residues in crops grown in clopyralid-contaminated soils

Abstract

In the present study, clopyralid residues in several crops grown in soils contaminated with clopyralid from compost made from animal manure were determined. Two field trials (cabbage and lettuce) and four pot trials (turnip, spinach, broccoli, and komatsuna) were conducted. An efficient extraction and cleanup procedure for analyzing clopyralid from crops followed by LC/MS/MS was developed. The residue levels of clopyralid in crops were from trace to 0.04 mg/kg, which were lower than the maximum residue limits (MRLs) permitted by the food sanitation law in Japan, with the exception of the komatsuna leaf trial.