Development of a Fast Method for the Determination of the Insecticide Fipronil and its Metabolites in Environmental Waters by SPE and GC-ECD

Abstract

Um método eficiente e sensível para a determinação simultânea do inseticida fipronil e seus principais metabólitos fipronil desulfinil, fipronil sulfeto e fipronil sulfona em águas superficiais foi desenvolvido e validado. Fipronil e seus metabolitos foram determinados por cromatografia gasosa com detecção por captura de elétrons (GC-ECD) após uma etapa de pré-concentração empregando extração em fase sólida (SPE). Os parâmetros de validação avaliados incluíram curva analítica e linearidade, limites de detecção (LOD) e de quantificação (LOQ), precisão e exatidão. GC-ECD apresentou uma boa resposta para fipronil e seus metabólitos, e todas as curvas analíticas apresentaram coeficientes de determinação superiores a 0,995. Os LODs do método foram 2,5 ng L -1 para fipronil e 2,0 ng L -1 para cada metabólito. Todos os valores de recuperação variaram de 81,3 a 112,3%, com valores de desvio padrão relativo (RSD) inferiores a 14,2%. O método proposto foi aplicado com sucesso em amostras de água de lavoura de arroz irrigado.An efficient and sensitive method for simultaneous determination of the insecticide fipronil and its main metabolites fipronil desulfinyl, fipronil sulfide and fipronil sulfone in surface water was developed and validated. Fipronil and its metabolites were determined by gas chromatography with electron capture detection (GC-ECD) after a preconcentration step using solid phase extraction (SPE). The evaluated validation parameters included analytical curve and linearity, limit of detection (LOD) and quantification (LOQ), precision and accuracy. GC-ECD presented a good response for fipronil and its metabolites, and all analytical curves showed determination coefficients higher than 0.995. The LOD values of the method were 2.5 ng L -1 for fipronil and 2.0 ng L -1 for each metabolite. All recovery values were between 81.3 and 112.3%, with relative standard deviation (RSD) values lower than 14.2%. The proposed method was successfully applied to the analysis of water samples from flooded rice fields.

Determination of fipronil and its metabolites in environmental water samples by meltblown nonwoven fabric‐based solid‐phase extraction combined with gas chromatography‐electron capture detection

“…The previous methods were mainly based on SPE and the sorbent generally had two sources, including commercial SPE cartridges and new SPE sorbent synthesized in the laboratory. Compared with the commercial SPE cartridges like C18 [18,19,24] and SDB-RPS [6], our self-made meltblown SPE cartridge could be reused and the core sorbent was taken from the medical mask, which was cheap and easy to obtain. Compared with the newly synthesized SPE sorbent, the preparation of meltblown SPE cartridge did not involve any chemical synthesis process, which fully met the needs of green analytical chemistry.…”

“…Under natural conditions, fipronil can be degraded into fipronil desulfinyl, fipronil sulfide, and fipronil sulfone through photolysis, reduction, and oxidation, while the toxicity of these degradation products is higher than that of the parent compound [12][13][14][15][16][17]. Studies had shown that 60-98% of pesticides stay in soil or air dust during the usage process, which could be transferred to natural water bodies through precipitation, surface runoff, soil leaching, and other ways [18,19], causing pollution to surface water and potential dangers to human health [20][21][22]. Therefore, it is significant to establish a simple, rapid, and effective method to determine fipronil and its metabolites in environmental water samples.…”

Immunoassays and Emerging Analytical Techniques of Fipronil and its Metabolites for Food Safety: A Review

“…66,67 A study on the toxicity of fipronil and its metabolites to crayfish showed that the 96 h LC 50 values of fipronil, fipronil-sulfone, fipronil-sulfide, and fipronil-desulfinyl were 14.3, 11.2, 15.5, and 68.6 μg/L, respectively, which indicated that these metabolites of fipronil have equivalent or greater toxicity than fipronil. 68 Additionally, pesticide residues are a major obstacle in the application of fipronil, which ultimately enters the food chain and poses a risk to humans directly or indirectly. Due to its superior stability, the concentration of fipronil in egg whites and yolks remained unchanged after 10 min of cooking at 100 °C, after incubating for 8 h at 37 °C or after digestion in the small intestine, after which the concentration decreased by only approximately 30% in the large intestine.…”

“…The LC 50 values of fipronil for zebrafish larvae and common carp were 0.6 and 0.43 mg/L, respectively. A high dose of fipronil can result in abnormal larval development and lethality in zebrafish. , A study on the toxicity of fipronil and its metabolites to crayfish showed that the 96 h LC 50 values of fipronil, fipronil-sulfone, fipronil-sulfide, and fipronil-desulfinyl were 14.3, 11.2, 15.5, and 68.6 μg/L, respectively, which indicated that these metabolites of fipronil have equivalent or greater toxicity than fipronil . Additionally, pesticide residues are a major obstacle in the application of fipronil, which ultimately enters the food chain and poses a risk to humans directly or indirectly.…”

A Polyvinyl Alcohol Coated Copper Foam Solid Phase Extractor for Determining Fipronil and Fipronil Sulfone

“…The identification and quantification of fipronil and fipronil sulfone can be achieved by gas chromatography-electron capture detector (GC-ECD). GC-ECD as a technique is simple, efficient and sensitive for analyzing fluorine rich analytes (7,10). However, an effective sample preparation method is needed before analysis (7) to reduce the interferences that may manipulate the result.…”