Plant growth regulator residues in fruits and vegetables marketed in Yinchuan and exposure risk assessment

Abstract

Data on plant growth regulators (PGRs) in common fruits and vegetables remain deficient. Supermarkets and farmers’ markets in three districts, two counties, and one city in Yinchuan with high traffic flow were selected and randomly sampled using the five-point sampling method. The QuEChERS pre-treatment method, combined with high-performance liquid chromatography-mass spectrometry, was used for detection. High-end exposure to PGRs was calculated via the chronic dietary risk assessment method from the point assessment model. The linearity of the components was good, (range: 0.2–100 ng/mL) with correlation coefficients ≥ 0.9962. Of the 25 PGRs examined, 16 were detected. The exceedances were as follows: chlormequat chloride and succinic acid 2,2-dimethylhydrazide in three and one batches of fruits, respectively, and gibberellin in four and six batches of vegetables, respectively. The same batch of fruits and vegetables could contain multiple PGRs, with seven PGRs detected in green dates and six in strawberries. In total, 10 batches of sprouts, six batches of fresh mushrooms, five of fruits and vegetables, one of leafy vegetables, and one of melons had excessive amounts of PGRs. The mean and median exposures were 0.0–0.832 mg/d and 0.0–0.453 mg/d, respectively. Although individual exceedances of PGRs were observed, most were at low levels, indicating that the corresponding risk was acceptable for human consumption.