Determination of fipronil insecticide and its sulfone metabolite in internal organs of white albino rats

Yehia Mohamed Mohamed Salim

doi:10.14419/ijpt.v8i1.30661

Abstract

Fipronil is a popular insecticide against a wide range of household, urban, agricultural, animal pests. It gets converted into several metabolites in animals and humans but mainly to fipronil sulfone, which is more toxic and persistent. Therefore, the current study aimed to investigate the presence of fipronil and fipronil sulfone in tissues of internal organs of white albino rats using gas chromatography coupled with mass spectroscopy (GC-MS) after oral administration of rats of repetitive sublethal doses of fipronil for 14 days. Results showed that the R2 values of standard curves of detected compounds were 0.9871 and 0.9989 for FIP and fipronil sulfone, respectively with LOQ of fipronil and fipronil sulfone of 5 and 10 Âµg/g. Average recovery percentages were from 96.3Â±5.4 to 101Â±8.5% and 93.8Â±4.7 to 98.4Â±5.1% for fipronil and fipronil sulfone, respectively with RSD values lower than 10%. Fipronil was detected in all tested organs. It was concentrated with great amounts in the lungs, liver, and kidney followed by testes, spleen, and brain, while fipronil sulfone was detected in the liver, testes, spleen, and lungs tissues in descending order. Fipronil was biotransformed into fipronil sulfone at different organs of white albino rats and the GC-MS coupled with the QuEChERS extraction and clean-up method were efficient in detecting them in the internal organs of rats.Â

Highlights

Fipronil (FIP) is a contact and stomach new insecticide with a good selectivity between insects and mammals via blocking the γ-aminobutyric acid-gated chloride (GABA) channels
Its concentration was different from organ to the other, where great amounts detected in the lungs, liver, and kidney followed by testes, spleen, and brain in a descending order
Similar to results reported in the current study, it was reported that the major metabolite of fipronil is the sulfone and was detected in the brain, liver, kidney, fat, and feces of mice using GC and HPLC methods (Hainzl & Casida 1996; Gunasekara et al 2007)

Summary

Introduction

Fipronil (FIP) is a contact and stomach new insecticide with a good selectivity between insects and mammals via blocking the γ-aminobutyric acid-gated chloride (GABA) channels. It is widely used to control common household and plant pests such as termites, ants, spiders, and mosquitoes. It is a widespread urban-use insecticide that has acute toxicity to arthropods at low levels (Hainzl et al 1998; Ikeda et al 2004; Gan et al 2012). FIP (phenylpyrazole) is known to cause mild neurological and dermatological effects. Fipronil was reported to cause a variety of toxic effects on animals and humans, such as neurotoxic, hepatotoxic, nephrotoxic, reproductive, and cytotoxic effects on vertebrate and invertebrates (Wang et al 2016)

Methods

Results

Conclusion