A solid phase extraction reversed‐phase HPLC method for the simultaneous determination of methoprene, permethrin and selected metabolites in rat plasma and urine

Abstract

A method was validated and applied for the analysis of the insect growth regulator methoprene [Isopropyl (2E,4E)-11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate], its metabolite methoprene acid, the insecticide permethrin [3-(2,2-dichloro-ethenyl)-2,2-dimethylcyclopropanecarboxylic acid(3-phenoxyphenyl)methylester], and two of its metabolites, m-phenoxybenzyl alcohol and m-phenoxybenzoic acid, in rat plasma and urine using solid-phase extraction and reversed-phase high performance liquid chromatography. The analytes were separated using gradient of 55-100% acetonitrile in water (pH 4.0) at a flow rate ranging between 0.6 and 1.0 mL/min over a period of 20 min, and UV detection at 210 and 254 nm. The retention times ranged from 7.3 to 18.4 min. The limits of detection ranged between 50 and 100 ng/ml, while limits of quantitation were 100-150 ng/mL. Average percentage recovery of five spiked plasma samples was 83.6 +/- 3.9, 80.1 +/- 5.4, 82.1 +/- 4.4, 83.7 +/- 3.9 and 83.1 +/- 4.7, and from urine 79.3 +/- 4.3, 82.0 +/- 5.4, 80.7 +/- 4.2, 78.9 +/- 5.7 and 83.9 +/- 4.5 for methoprene, methoprene acid, permethrin, m-phenoxybenzyl alcohol and m-phenoxybenzoic acid, respectively. The method was linear and reproducible over the range of 100-1000 ng/mL. This method was applied to analyze the above chemicals and metabolites following their combined administration in rats.

Multiple stressor effects of methoprene, permethrin, and salinity on limb regeneration and molting in the mud fiddler crab (UCA pugnax)

“…Methoprene was not detected in the lowest concentration sample on day 22; this concentration is near the method's detection limit [31]. Methoprene concentrations were 0.023 6 0.008, 0.12 6 0.006, 0.98 6 0.07, 3.75 6 0.08, and 9.42 6 0.35 mg/L, whereas permethrin concentrations were 0.010 6 0.0002, 0.090 6 0.005, 0.22 6 0.09, 0.92 6 0.05, and 1.63 6 0.31 mg/L.…”

“…Briefly, crabs that were determined to be in intermolt (stage C 4 ) were induced to self-autotomize their fourth walking limb on their right side by pinching the merus with forceps following acclimation. Thawed methoprene samples were eluted from cartridges with HPLC-grade methanol and acetonitrile and then evaporated to 1 ml at 40uC under a nitrogen stream [31]. Each crab was randomly assigned to 1 of 16 treatment groups or controls and placed randomly into 1 of 10 water baths held at 25uC.…”

Bioanalytical Methods for The Quantification of Cis -Permethrin and Trans -Permethrin in Biological Samples

“…Several analytical strategies for the separation and determination of PERM in biological matrices have been reported [6][7][8][9][10][11][12]. However, using GC-NCI-MS has provided the most sensitive method for the bioanalysis of PERM…”

Cloud-point extraction followed by high pressure liquid chromatography with UV spectrophotometric detection for determination of permethrin in urine samples

“…Based on the literature, permethrin has been determined in different biological materials (plasma, blood and urine) with the use of solid-phase extraction [9][10][11][12]15 followed by analytical techniques such as HPLC-UV, LC-MS/MS and GC-MS or GC-MS/ MS. In order to compare the obtained results for the determination of permethrin in urine by the proposed CPE-HPLC-UV method, the experimental conditions and analytical parameters of the above-mentioned methods are noted in Table 3.…”

“…In order to compare the obtained results for the determination of permethrin in urine by the proposed CPE-HPLC-UV method, the experimental conditions and analytical parameters of the above-mentioned methods are noted in Table 3. In three cases, [9][10][11] the authors used the HPLC-UV method combined with solid-phase extraction for detection and quantication of permethrin in rat urine. The extraction recovery of permethrin from urine ranged from 77.9 to 83.9% and was a little lower or comparable with the proposed CPE procedure (mean 89.9%) and the limits of detection (0.050 mg mL À1 ) and quantication ranged from 0.100 to 0.150 mg mL À1 and were higher than those obtained in our method (LOD ¼ 0.025 and LOQ ¼ 0.075 mg mL À1 ).…”