Li F. Comparative evaluation of different methods of determining pesticide residues in plant product

Pesticides have played an important role in improving the crop yield and eliminating the pests and diseases in modern agricultural production. However, the improper use of pesticides often leads to the excessive pesticide residues, which cause serious harm to human health and ecological environment. As we all known, leafy vegetables have obvious seasonality and economy, and the planting scale is not as large as that of grain crops, and their growth cycle is short, so the requirements for external environmental conditions are stricter. Therefore, the differences and laws of pesticide absorption and transport of leafy vegetables are studied, which are important for pesticide pollution control. Additionally, it is particularly urgent to develop a simple, efficient, and low-cost detection technology for analysing the pesticide residues to strictly control the excessive pesticide residues. Compared with traditional detection methods, the electrochemical sensing analysis technology has several advantages such as high efficiency, simple analysis operation, and inexpensive measurement equipment. In this work, the differences of pesticide absorption and transfer in different leaf vegetables were studied, and the dynamic absorption and accumulation rules were explored in hydroponic lettuce. Otherwise, a series of electrochemical sensor by using several nanocomposite materials as modification materials of sensing electrodes were proposed for the pesticide detection. Under the optimal conditions, the fabricated electrochemical sensors showed highly sensitive pesticide detection performance with satisfactory recovery rates and low limit of detection (LOD) values. The good repeatability, reproducibility, stability, and anti-interference can be achieved at the fabricated sensors. Moreover, the accurate and sensitive quantitative analysis performance can be obtained at the fabricated sensor for the detection of pesticide residues in real samples.