Pesticide residues in water test kit for sustainable and safe agriculture

Farmers in Thailand still largely use chemical herbicides, especially paraquat and atrazine, to control weeds on their farms. According to research by the Office of Agricultural Economics, in 2019, Thailand imported almost 10 million kilograms of paraquat and close to 3.5 million kilograms of atrazine.

The residues of these herbicides cause harm to the environment, living creatures, and our health.

As head of the research project on pesticide residues in water test kit for sustainable and safe agriculture, Associate Professor Dr. Thanyalak Chaisuwan, Deputy Dean for Research, The Petroleum and Petrochemical College, Chulalongkorn University, has collaborated with Assistant Professor Dr. Luxsana Dubas, Department of Chemistry, Faculty of Science, Chulalongkorn University, in developing a test kit to measure pesticide contaminants in water.

The kit employs synthesized porous nano carbon materials together with color analysis techniques to achieve accuracy and reduce problems from herbicide residues. The research is conducted by Ph.D. students of the Department of Chemistry, Faculty of Science, Chulalongkorn University, forming a dual field research to solve the problems of pesticide contamination in water, which is hard to detect.

Assoc. Prof. Dr. Thanyalak explained that Thailand is an agricultural country, resulting in heavy use of pesticides and chemicals in the production of agricultural products. In 2021, Thailand ranked 7 in the world for the number of pesticides and chemicals used in agriculture, amounting to 0.65 kilograms of such substances per rai. Research has shown that chemicals like paraquat and atrazine can lead to Parkinson's disease and cancer if accumulated in the body.

This has led to the development of a pesticide contaminant in water test kits, which uses absorbent materials and compares colors that are sensitive to paraquat and atrazine in small amounts. The materials used are made from synthetic polymer, achieved by burning organic chemistry materials in inert air until they become coal-like. The result is light-weight porous carbon with holes too small for the naked eye and the diameter of which is measured in nanometers. The research yielded satisfactory results. In the future, the research will be furthered by applying the materials to detect other substances.

Assoc. Prof. Dr. Thanyalak added that Thailand has over 150 million rai of farmland, with revenue from agriculture accounting for 10% of the country's GDP. The government's push to reduce the income gap and low income per capita, as well as their support of Smart Farming, requires technology. The development of a test kit for pesticide contaminants in water will be truly beneficial for sustainable and safe agriculture.

As of now, this test kit is a prototype which can be tested in actual conditions.