Bionanomaterial composed of Bradyrhizobium japonicum and graphene oxide for determination of mercury in water and fruit juice samples

INGRASSIA, ESTEFANÍA B.; FIORENTINI, EMILIANO F.; WUILLOUD, RODOLFO G.; ESCUDERO, LETICIA B.

JOURNAL OF FOOD COMPOSITION AND ANALYSIS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2024 vol. 127

0889-1575

In the present work, the synthesis of a novel hybrid bionanomaterial formed by the bacteria Bradyrhizobiumjaponicum (BJ) and the graphene oxide (GO) nanomaterial implemented in the miniaturized dispersive microsolidphase extraction technique (D-μ-SPE) was reported for the first time for the preconcentration and determinationof Hg in water and fruit juice samples after a multivariate optimization. Selective Hg extraction wasachieved by forming a complex with ammonium pyrrolidinedithiocarbamate (APDC) reagent and a multivariatestudy was performed to optimize the experimental conditions. The optimal Hg extraction conditions for 25 mL ofsample were 3 mg of BJ@GO, NaNO3 at 1% (w/v), 6 min of vortex agitation and 9 min of centrifugation. Forback extraction, 500 μL of 14 mol L􀀀 1 HNO3, 6 min of vortex agitation and 6 min of centrifugation were usedfollowed by detection by cold vapor atomic fluorescence spectrophotometry (CV-AFS). Under optimizedexperimental conditions, an extraction efficiency of 98%, a detection limit of 0.08 μg L􀀀 1, a relative standarddeviation of 3.5% (at 1 μg L􀀀 1 of Hg, n = 10), and a linear range of 0.26 - 4.0 μg L􀀀 1 were obtained. In addition,the sustainability of the method developed through the use of the Analytical GREEnness calculator (AGREE)software was evaluated, obtaining a greenness degree of 0.59. This work reports the first application of BJ@GOalong with the D-μ-SPE technique for trace Hg determination water and fruit juice samples. In this way, thisresearch work allows the exact and precise determination of low Hg concentrations in water and juice samples,which allows the evaluation of the contamination degree by this toxic metal in beverages widely consumed bythe population.