THE IMPORTANCE OF A SENSITIVE METHOD FOR PESTICIDES ANALYSIS IN DRINKING WATER SURVEILLANCE

Resumo

INTRODUCTION: Brazil is one of world's largest consumers of pesticides, which arefound in food, soil, and water used for human consumption. Therefore, there is a need fora reliable and sensitive analytical method to detect these compounds in the environment.OBJECTIVE: To verify the importance of sensitivity analytical method for pesticidesevaluation in drinking water surveillance in 2024. METHODOLOGY: The method for99 current used pesticides analyses consisted in solid-phase extraction (C18 cartridges),elution and concentration by nitrogen flow, followed by detection and quantification in aGC-MS/MS equipment. RESULTS AND CONCLUSION: Limits of detection andquantification limits for most analytes ranged from 0.003 to 0.018 µg L⁻¹ and 0.0096 to0.0540 µg L⁻¹, respectively. In 2024, approximately 3,208 samples were received from21 Brazilian states, with 1,485 testing positive for any pesticide, above LOD. Thesesamples were compared to previous limits of detection and quantification from 2023,which ranged from 0.016 to 1.156 µg L⁻¹ and 0.048 to 3.504 µg L⁻¹. Notably, for example,Pernambuco had 54% of positive samples, above LOD, under new limits, compared to17% under old limits. Paraná had 62% of positive samples, above LOD, under new limitsand 11% under old limits. The same happened in other states, but on a smaller scale. Thissignificant increase in positive samples is due to equipment sensitivity amplification,combined with optimized and validated methodology for analyzing pesticides in drinkingwater. The 5-fold reduced limits demonstrated the difference in positive samplepercentages compared to both perspectives. Despite all results were below maximumallowed values in Brazilian ordinance for drinking water, pesticides are poisons and notdesirable in water for consumption. The sensitive method ensures greater result reliabilityand contributing to state and municipals surveillance work.