Procedimento eletroanalitico para determinação de pireno em água subterrânea usando eletrodo de carbono vitreo modificado com oxido de grafeno reduzido

Abstract

Pyrene is considered an emerging microcontaminant due to its persistent toxicity in living beings, being a compound capable of spreading rapidly through tissues, as well as crossing the blood-brain barrier leaving the central nervous system unprotected, allowing the passage of toxic substances found in the blood . Therefore, it is of great importance to control this contaminant in groundwater. The present work aimed to propose a procedure for the determination of pyrene in groundwater at a gas station using a voltammetric eletrodo based on reduced graphene oxide in Britton Robson (BR) 0.5 mol L -1

, pH 4.0 buffer solution. The proposed eletrodo showed an excellent electrochemical performance for the oxidation of pyrene under optimized experimental conditions. Through the standard deviations of the calibration curves, LD and LQ were calculated for the analyte, where the detection limit obtained was 5.6 x 10-08 and the quantification limit 1.8 x 10-07. The linearity range varied between 9.9x10-6 mol L-1

to 4.7x10-5 mol L-1

. The coefficients of variation (precision) of the electroanalytical measurements of the eletrodo were 7.01% (repeatability) and 1.57% (reproducibility). The application of the eletrodo to a real sample was carried out using the enrichment method. The developed eletrodo was successfully applied in the determination of pyrene in a groundwater sample, in which a recovery of 101.3% (accuracy) was obtained. And the modified electrode showed a good electroanalytical response in terms of sensitivity and stability. These results indicate that this procedure is sufficiently suitable as an alternative method to determine the content of pyrene in groundwater.