Development of on-line spectrofluorimetric methodology for selenium monitoring in foods and biological fluids using Chrome azurol S quenching

SANTAROSSA, DÉBORA G.; FERNÁNDEZ, LILIANA P.

TALANTA

ELSEVIER SCIENCE BV

Año: 2017 vol. 172 p. 31 - 36

0039-9140

A novel, simple and accurate on-line green methodology for Se(IV) monitoring by molecular fluorescence hasbeen developed. Because the analyte does not exhibit fluorescence, the organic dye Chrome azurol S (CAS) hasbeen chosen to allow detection. The effect of metal-quenching on CAS excitation and emission conditions(λex=300 nm; λem=407 nm) was used as criterion for analyte quantification in presence of sodium cholate bilesalt (NaC). The quenching mechanism was explored, and it can be classified as a collisional type with a Stern-Volmer constant value of 3.0×107 mol L−1. To improve the sampling rate, minimize the reagent consumptionand generated wastes, an on-line configuration was designed. Experimental variables that affect the fluorimetricsensitivity were optimized using uni-variation assays. Under optimal experimental conditions, the limit ofdetection was 0.27 μg L−1 with a lineal range for Se(IV) concentration from 0.84 to 6.00 μg L−1. The developedmethodology is low cost and fast sampling, allowing Se(IV) quantification in the presence of other common ions.Bulbous vegetables and biological samples were successfully analyzed with an average recovery close to 100%.