Residue analysis of picoxystrobin in oriental melon using gas chromatography coupled with electron capture detection and mass spectrometric confirmation: application to dissipation kinetics and risk assessment

Abstract

This study was carried out to determine the residual amounts of picoxystrobin in oriental melon ( L.) grown under plastic house conditions at two different sites. Samples collected over 10 days were extracted using acetonitrile and salting out (using solid sodium chloride) and purified using Florisil SPE cartridges. The analyte was determined using GC-ECD and field-incurred residues were verified using GC-MS. The calibration curve was linear over the range 0.02-2.0 mg/L with a = 0.9998. The LOD and LOQ were 0.003 and 0.01 mg/kg, respectively. Recoveries, tested at three spiking levels, were satisfactory with rates in the range 87.7-101.5% and relative standard deviations ≤9.6. The dissipation half-lives were 3.4 and 3.7 days for sites 1 and 2, respectively. Hazard estimates obtained using hazard quotients revealed no health risk from the suggested pesticide application dosage when considering an adult's body weight, oriental melon consumption, and the acceptable daily intake of picoxystrobin.

Dissipation, residues and risk assessment of pyraclostrobin and picoxystrobin in cucumber under field conditions

“…reported the half‐lives of picoxystrobin were 1.5–8.6 days in soil and 2.1–2.8 days in peanut seedlings 14 . The dissipation half‐lives of picoxystrobin in oriental melon were 3.4–3.7 days reported by Kabir et al 15 . You et al .…”

“…On the whole, pyraclostrobin and picoxystrobin exhibited a rapid dissipation in cucumbers in most sites, which was consistent with literature reports in different matrixs. 14,15,25 For example, Zhu et al reported the half-lives of picoxystrobin were 1.5-8.6 days in soil and 2.1-2.8 days in peanut seedlings. 14 The dissipation half-lives of picoxystrobin in oriental melon were 3.4-3.7 days reported by Kabir et al 15 You et al's results showed pyraclostrobin dissipated quickly in maize plant with half-lives of 1.6 to 1.7 days.…”

“…14,15,25 For example, Zhu et al reported the half-lives of picoxystrobin were 1.5-8.6 days in soil and 2.1-2.8 days in peanut seedlings. 14 The dissipation half-lives of picoxystrobin in oriental melon were 3.4-3.7 days reported by Kabir et al 15 You et al's results showed pyraclostrobin dissipated quickly in maize plant with half-lives of 1.6 to 1.7 days. 25 However, data from Guangdong showed no dissipation but an increase at 1 day after spraying.…”

“…14 Kabir et al developed an analytical method for the determination of picoxystrobin in oriental melon using gas chromatography (GC)-electron capture detection (ECD) and mass spectrometry (MS). 15 Other than that, no available reports have put forward a method to detect pyraclostrobin and picoxystrobin simultaneously with LC-MS/MS in cucumber, and neither have there been any reports on the dissipation behavior of pyraclostrobin and picoxystrobin on cucumbers under field conditions, which is essential to evaluate their persistence in the environment.…”

“…16 In 2017, Kabir et al determined the residual amounts of picoxystrobin in oriental melon in two different sites and assessed the long-term risks. 15 These articles focused more on fruits, and the risk assessments for pyraclostrobin and picoxystrobin on cucumber were not researched. Furthermore, the number of filed test sites in these reports were less than two, which could not represent the consumption data for a whole country or region.…”