Abstract
A modified QuEChERS technology combined with UPLC-Q-TOF-MS/MS residue analytical method for propyrisulfuron in natural paddy field environment was developed. Propyrisulfuron residues in paddy water, soil, rice plants, brown rice and rice husk samples was extracted with 1.0 % acetic acid-acetonitrile (v/v) solution and separated on a reversed-phase C18 column with a mobile phase of 0.1 % formic acid water-acetonitrile eluted by isometric elution (60/40, v/v), and quantified in high-resolution multiple reaction monitoring (MRMHR) scanning mode providing more accurate confirmatory information. The lower limit of quantification (LOQ) of propyrisulfuron in all the five paddy matrices was in a range of 1.24 ∼ 3.85 µg/kg, and all calibration curves showed good linearity (R2 > 0.991) in a certain concentration range (10 ∼ 1000 µg/kg). At the spiked level of 10 ∼ 200 µg/kg, the intra-day and inter-day average recoveries and relative standard deviation were 82.80 ∼ 106.93 % and 1.81 ∼ 5.51 %, 83.05 ∼ 105.84 % and 2.25 ∼ 4.61 %, respectively, for analysis on three consecutive days, and there was a good retention time repeatability of 15 consecutive injections with RSD of 0.15 ∼ 0.17 %, indicating a high sensitivity, specificity, accuracy and precision. All paddy filed environmental samples frozen at −20 °C were analyzed within 10 weeks after collection for a good storage stability. Propyrisulfuron dissipated in paddy water, soil and rice plants at application doses of 30, 45 and 60 g a.i./ha with half-lives of 1.37 ∼ 1.81, 4.10 ∼ 5.35 and 3.70 ∼ 4.42 days in 2020, 1.44 ∼ 2.04, 4.27 ∼ 5.83 and 3.68 ∼ 4.49 days in 2021, respectively. The final propyrisulfuron residual levels of two years in brown rice, rice husks and rice plants samples prior to harvest were lower than 8.18 µg/kg, and its removal rate was in a range of 1.40 to 98.27 % by several simple available household technologies. Moreover, the chronic dietary risk in brown rice at recommended dose for Chinese residents of different age groups was low and acceptable for daily consumption.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.