Electroanalysis of Insecticides at Carbon Paste Electrodes with Particular Emphasis on Selected Neonicotinoid Derivatives

Abstract

1.1 Recent trends in the use of insecticides Insecticides are substances from the group of pesticides intended for preventing, destroying, repelling or mitigating insects (Pesticide, 2011). Although there are benefits to the use of insecticides, there are also drawbacks, such as potential toxicity to humans and other animals. Residues in fruit and vegetables, cereals, processed baby food and foodstuffs of animal origin are controlled through a system of statutory maximum residue limits (MRLs) (Tuzimski, 2011). The increasing use of pesticides, especially herbicides and insecticides, in agriculture, forestry, and domestic activities for controlling pests causes pollution of the water resources, environment, as well as of many food stuff. The leaching run-off from agricultural and forest lands; deposition from aerial applications and residua from the industrial wastewater treatment are mainly responsible for the water contamination (Gupta, 2004). The pesticides form a strong class of water and environment pollutants, as they are sometimes non biodegradable. The toxicity of pesticides and their degradation products make these chemical substances potentially hazardous contaminants of the environment (Schultz et al., 2003). According to the Stockholm Convention on Persistent Organic Pollutants, nine of the dozen of the most harmful and persistent organic chemicals are pesticides (Ridding the World of POPs: A guide to the Stockholm Convention on Persistent Organic Pollutants, 2005; Pesticide, 2011). The insecticides can be grouped by means of sorting into chemical families. Major insecticide families include organochlorines, organophosphates, carbamates, and neonicotinoids. Organochlorine hydrocarbons (e.g. DDT) could be separated into dichlorodiphenylethanes, cyclodiene compounds, and other related compounds. They operate by disrupting the sodium/potassium balance of the nerve fiber, forcing the nerve to transmit continuously. Their toxicities vary greatly, but they have been phased out because of their persistence and potential to bioaccumulate (Kamrin, 1997). For instance, due to