Residues and Dietary Risk Assessment of Prohexadione-Ca and Uniconazole in Oryza sativa L. and Citrus reticulata Blanco by Liquid Chromatography-Tandem Mass Spectrometry

Abstract

A simple and sensitive method for the simultaneous quantitation of prohexadione-Ca and uniconazole in the field experiment of Oryza sativa L. and Citrus reticulata Blanco was established using solid-phase extraction (SPE) with polymer anion exchange (PAX) and Florisil followed by LC-MS/MS. The method demonstrated excellent linearity (R2 > 0.999 0), trueness (recoveries between 95~105%), precision (CVs between 0.8~12%), sensitivity, and repeatability (LOQ of 0.05 and 0.01 mg/kg, respectively). Residue tests were conducted in the field at 12 representative sites in China, revealing final concentrations of prohexadione-Ca and uniconazole in brown rice, rice hull, and rice straw to be below 0.05 mg/kg, while in whole citrus fruit and citrus pulp, they were below 0.01 mg/kg. These were below the maximum residue limits specified in China. The chronic dietary risks of prohexadione-Ca and uniconazole in rice crops and citrus fruits were calculated to be 0.48% and 0.91%, respectively. Our research suggests that the chronic risk associated with the daily consumption of rice crops and citrus fruit at the recommended dosage is acceptable.

Dihydrogibberellin improves grain yield and lodging resistance of direct seeded rice

“…The primary physical parameters that influence the resistance of rice to lodging are plant height, stem diameter, and coarseness. It has been reported that reducing the height of rice plants and increasing the diameter of stalks and thickness of culm walls significantly improves lodging resistance (Ye et al., 2023). The mechanical strength of basal internodes mainly depends on carbohydrates, such as nonstructural and structural carbohydrates (L. Wu et al., 2017).…”