Paraquat quantification in deposits from drinking water networks

Abstract

The aim of this work was to develop an expedite analytical methodology to evaluate the paraquat (PQ) contamination level in deposits 5 proceeding from drinking water networks. To our knowledge, no other study has been focused on this matter, which is of crucial importance, for instance, to obtain a fast response after a suspicion of contamination (emergency situation). Three deposits representative of those typically found in drinking water networks were used: two iron-based -S2 and S3, and a calcium rich one -S4. The analytical method consists of an easy and fast extraction step, using a saturated ammonium chloride solution, followed by direct injection in a high performance liquid chromatograph with diode array detector (HPLC-DAD). A matrix-matched calibration was performed for paraquat, in 10 the range of 5 to 193 µgPQ g -1 deposit, and a limit of detection of 0.1 µgPQ g -1 deposit was reached. The good percentages of recovery (90-101% on average) and the low relative standard deviations observed for the PQ-S3 system (3, 4 and 2% for 20, 80 and 160 µgPQ g -1 deposit, respectively) enable a reliable quantification of paraquat, even at the lowest contamination levels. The developed analytical methodology can also be extended for diquat and proved to be also suitable for paraquat quantification in other types of deposits.

Response to: Neurotoxicity of paraquat and paraquat-induced Parkinson's disease

“…However, an important limitation is that very little research has been published on the quantification of PQ in drinking water deposits or in soil. 22 Our article cites additional papers detecting PQ in groundwater. New advances in detection techniques may prove useful in ecotoxicological studies investigating the environmental chemistry of PQ.…”