Determination of chlorpyrifos using GC-FID in pesticides and human plasma; method validation with greenness assessment

Abstract

About 3.70 million tons of pesticides are consumed annually to improve agricultural revenues. Organophosphate (OP) is a significant pesticide class, representing approximately 40% of pesticides' global sales. Chlorpyrifos (CPF) has been an OP pesticide commonly used to prevent horticultural and domestic pests for the past 25 years. Although CPF was banned from household products by the United States Environmental Protection Agency (US-EPA) in the year 2000, its current sales in the US alone exceed 5,000 tons. Other authorities, such as European, Canadian and Egyptian, have also discontinued its use since 2020. Therefore, it is necessary to analyze CPF as a counterfeit pesticide in products and biological samples in the coming years. CPF has high toxicity, representing neurological and cardiovascular threats. The proposed research aims to develop a novel, fast, and cost-effective methodology to estimate CPF in pesticide products and biological human plasma using gas chromatography (GC) with a flame ionization detector (FID). Notably, only a few GC-FID methods were reported for CPF analysis in marketed products. Still, none has yet been reported for its determination in plasma using GC-FID despite being greener, cheaper, and simpler than GC-tandem mass spectrometry (MS/MS). Both procedures were validated according to the International Council for Harmonization (ICH) guidelines. The retention time was 13.3 min. Linearity was perceived in the concentration of 20.0–100.0 μg/mL, with a coefficient of determination of 0.9909 for analytical and 0.9905 for bio-analytical application, respectively. The detection (LOD) and quantification limits (LOQ) were 0.29 and 0.87 μg/mL. Further, the greenness of the developed technique was assessed and compared to some other reported methodologies. The validation and greenness results indicate that both methods are reliable and sensitive, making them suitable for routine quality control of CPF in marketed products and biological samples.