Development of Rapid Cleanup Method Using New Cleanup Agents for Analysis of Pesticide Residues in Tea

Cleanup using two types of agents (S-NH₂ and S-Si) developed by the authors was investigated with the aim of removing interfering substances such as catechin and caffeine to enable analysis of pesticide residues in tea. S-NH₂ and S-Si removed approximately 100% of catechin and caffeine in 6 species of tea. Recoveries of 61 pesticides in tea were tested at the level of 0.1 μg/g, and 44 pesticides showed recovery within the range from 70 to 120%, with RSD of less than 10%. With cleanup using S-NH₂ and S-Si, pesticide residues in tea could be analyzed within two hours.