title: 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.
abstract: 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 disk 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 zero th 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.
authors.affiliation: Instituto de Química de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Talio
authors.affiliation: Área de Química Analítica, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Karen
authors.initials: K
authors.lastname: Zambrano
authors.affiliation: Área de Química Analítica, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Marcos
authors.initials: M
authors.lastname: Kaplan
authors.affiliation: Instituto de Química de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis, Argentina.
authors.forename: Mariano
authors.initials: M
authors.lastname: Acosta
authors.affiliation: Área de Química Analítica, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina; Instituto de Química de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis, Argentina.
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Gil
authors.affiliation: Área de Química Analítica, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Marta O
authors.initials: MO
authors.lastname: Luconi
authors.affiliation: Área de Química Analítica, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina; Instituto de Química de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis, Argentina. Electronic address: lfernand@unsl.edu.ar.
authors.forename: Liliana P
authors.initials: LP
authors.lastname: Fernández
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D066300:Electronic Nicotine Delivery Systems; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D007454:Iodides / Q000737:chemistry; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D002593:Cetrimonium Compounds; D005456:Fluorescent Dyes; D007454:Iodides; D012235:Rhodamines; D013501:Surface-Active Agents; D007854:Lead; C029773:rhodamine B; D000077286:Cetrimonium
keywords: Lead traces; Rhodamine B; Solid surface fluorescence; e-Cigarettes