Residuesbehavioranddietaryintakeriskassessmentofmalathionin

Cucurbitapepo

L.

The residues of malathion in Cucurbita pepo. was determined using gas chromatography equipped with flame photometric detector (GC-FPD). The  standard residue trials of malathion in C. pepo were carried out in Hunan, Shandong, Beijing, Anhui, Shanxi and Heilongjiang in 2016. The dietary intake risk assessment to different populations and different foods based on the residual data of malathion was conducted. The C. pepo samples were extracted with acetonitrile, determined by GC-FPD after the displacement of acetonitrile with acetone. With the fortified level from 0.02 to 8.0 mg/kg in C. pepo samples, the recoveries ranged from 88% to 109% with the relative standard deviations (RSD) of 5%. The limit of quantitation (LOQ) of the method was 0.02 mg/kg. The dissipation dynamic test results obtained from Hunan and Shandong showed that malathion was easily degradable, and the half-life of malathion was 2.74-4.65 days. The final residues in C. pepo from six provinces were < 0.02-0.049 mg/kg with interval 3, 5 and 7 days after last applied. The dietary risk assessment results showed that the national estimated daily intake (NEDI) was between 0.115-0.207 μg/(kg bw·d) and the risk quotients (RQ) were between 0.000 4-0.000 7 for different populations in China. The total dietary exposure risk assessment results indicated that the NEDI of malathion in all kinds of foods was 82.251 μg/(kg bw·d), and the RQ was 0.275 1, which demonstrated that malathion applied to C. pepo had low risk. The maximum residue limit (MRL) of malathion in C. pepo is recommended to be 0.1 mg/kg in China, which would ensured dietary intake safety of C. pepo.