Efficacy of Thin Layer Chromatography in the Detection and Separation of Various Pyrethroids from Gastric Aspirate Samples

Abstract

Pyrethrins are plant toxins found in certain Chrysanthemum flowers that are poisonous to insects. Their synthetic derivatives, called pyrethroids are available in markets as a class of pesticides used in the agricultural, textile and wood industry. They are also found in day-to-day products, such as insect repellents and topical hair lice medication. Pyrethroids are neurotoxic agents and while most pyrethroids are relatively safe for mammals, the easy availability and chronic or excess exposure to it has resulted in an increase in the number of poisoning cases reported in recent years. Pyrethroid exposure can cause oxidative stress, inflammation, and DNA damage. Epidemiological studies, although still limited, have suggested that environmental pyrethroid exposure may impair neurodevelopment, interfere with reproductive health, and increase the risk of major chronic diseases, such as diabetes, cardiovascular disease (CVD), and Parkinson disease. Quick and accurate detection is therefore, a necessary part of identifying and diagnosing pyrethroid poisoning. Our study aimed to determine how effective TLC (Thin Layer Chromatography) is, as a method for analysis of pyrethroid compounds in a biological sample such as gastric aspirate and the best solvent and mobile medium for the same. 

Materials and methods-A market study was conducted and pyrethroid containing products which are suitable for the research were chosen. These are mostly daily-use compounds for household and agricultural purposes. ER grade/Pure grade solvents were used for extraction and mobile phase preparation. Other items used for the study were TLC plates, capillary tubes, Whatman filter paper and glass wares. Gastric aspirate samples were used. The technique chosen for the study is the Thin Layer Chromatography method. 

Conclusion -Our results demonstrated that TLC was effective in separating and differentiating between the 8 pyrethroid compounds identified from the 12 products that were tested and the combination of Hexane and Acetone (1:1) was found to be the best solvent system among the two used. Cyclohexane, Acetone and Chloroform (70:25:5) was the best mobile phase from the five tested. We also found that binary solvent extraction was better than single solvent extraction in most of the samples tested.