A versatile hydrogel including bentonite and gallocyanine for trace Rhodamine B analysis

Abstract

This study presents a simple and useful method for the effective and sensitive determination of Rhodamine B in cosmetic samples. Solid phase extraction ( SPE) was applied to samples containing Rhodamine B prior to HPLC analysis. The method is based on adsorption of Rhodamine B molecules on a kind of hydrogel consist of poly acryl amide, bentonite, and gallo cyanine (PAA-B-GC). The amount of Rhodamine B after preconcentration was determined by HPLC-DAD at 556 nm. The experimental variables such as pH, amount of adsorbent, samples volume, type and volume of eluent, adsorption and elution time were investigated and optimized. The detection and quantification limits of the developed method were calculated as 2.98 and 9.92 ng mL(-1), respectively. The method has linear response in the range of 10-1200 ng mL(-1) and showed satisfactory reproducibility with intra-day and inter-day relative standard deviations less than 3.50%. Finally, the developed material and method was successively applied for determination of Rhodamine B residues in various cosmetic samples. (C) 2016 Elsevier B.V. All rights reserved.