FLUORESCENCE METHOD USING ON-LINE SODIUM CHOLATE COACERVATE SURFACTANT MEDIATED EXTRACTION FOR THE FLOW INJECTIONS ANALYSIS OF RHODAMINE B

ACOSTA MARÍA GIMENA; M. CAROLINA TALIO; LUCONI MARTA; WILLIE L. HINZE; FERNÁNDEZ L.P.

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 129 p. 516 - 522

0039-9140

An on-line surfactant mediated extraction method in a flow injection analysis format with fluorescence detection for the determination of Rhodamine B (RhB) in food condiments was developed. The sample was extracted using the phase separation behavior exhibited by the bile salt surfactant, sodium cholate (NaC), upon addition of sodium dodecylsulfate (SDS) in the presence of acid at room temperature. RhB was extracted when the coacervate of NaC/SDS was formed and then it was on-line collected in a glass-wool packed minicolumn from which it was eluted with a 1.0 mol L-1 HCl solution. Analytical detection of RhB took place by spectrofluorimetry (λex = 555 nm; λem = 575 nm). Good linearity (R2 = 0.99) was obtained over the concentration range 0.4 - 479.0 μg L-1 RhB. The detection (LOD) and quantification (LOQ) limits were 0.12 and 0.40 μg L-1, respectively. The method was successfully applied for analysis of RhB in food condiments and spiked samples. The average recoveries ranged from 95.3% to 118.9% at the spiked concentration levels of 1.19 and 2.39 μg L-1. Under optimized conditions, a throughput of 50 samples per hour was achieved. The proposed method may be a valuable tool not only for quality control of food condiments and similar food confectioneries but for the analysis of a variety of other RhB-containing samples as well.