NEW SOLID SURFACE FLUORESCENCE METHODOLOGY FOR LEAD TRACES DETERMINATION USING RHODAMINE B AS FLUOROPHORE AND COACERVATION SCHEME. APPLICATION TO LEAD QUANTIFICATION IN E-CIGARETTE REFILL LIQUIDS.

MARÍA CAROLINA TALIO; ZAMBRANO, KAREN; MARCOS KAPLAN; ACOSTA MARIANO; RAUL GIL; MARTA LUCONI; FERNÁNDEZ L.P.

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam (2015); Año: 2015 vol. 143 p. 315 - 319

0039-9140

A new environmental friendly methodology based on fluorescent signal enhancement of rhodamine B dye is proposed for Pb(II) traces quantification using a preconcentration step based on the coacervation phenomenon. A cationic surfactant (cetyltrimethylammonium bromide, CTAB) and potassium iodine were chosen for this aim. The coacervate phase was collected on a filter paper disc and the solid surface fluorescence signal was determined in a spectrofluorometer. Experimental variables that influence on preconcentration step and fluorimetric sensitivity have been optimized using uni-variation assays. The calibration graph using zeroth order regression was linear from 7.4×10−4 to 3.4 μg L−1 with a correlation coefficient of 0.999. Under the optimal conditions, a limit of detection of 2.2×10−4 μg L−1 and a limit of quantification of 7.4×10−4 μg L−1 were obtained. The method showed good sensitivity, adequate selectivity with good tolerance to foreign ions, and was applied to the determination of trace amounts of Pb(II) in refill solutions for e-cigarettes with satisfactory results validated by ICP-MS. The proposed method represents an innovative application of coacervation processes and of paper filters to solid surface fluorescence methodology.