Preconcentration and determination of β-carotene nanoparticles in fruit and juice samples based on a micelle mediated system

Abstract

This article presents a simple, green and low cost analytical method for preconcentration and determination of β-carotene nanoparticle content in fruit and juice samples. The method is based on the enrichment of β-carotene nanoparticles in a non-ionic surfactant phase using cloud point extraction (CPE) followed by UV-vis spectrophotometric determination at 468 nm. The influence of chemical variables such as pH of the sample solution, type and volume of the buffer, electrolyte type and concentration, surfactant concentration, temperature and incubation time on the CPE procedure was studied. Under optimum conditions the method yielded a linear calibration curve in the range of 2.80 × 10⁻⁸ to 2.52 × 10⁻⁶ mol L⁻¹ for β-carotene nanoparticles (r = 0.9978). The LOD and LOQ were found to be 1.12 × 10⁻⁸ mol L⁻¹ and 3.74 × 10⁻⁸ mol L⁻¹, respectively. The relative standard deviations (RSD) for eight replicate measurements of 1.68 × 10⁻⁶ mg L⁻¹ and 2.80 × 10⁻⁷ mol L⁻¹ of BC-NPs were 3.2% and 5.6%, respectively. The developed CPE method was applied to the analysis of watermelon, tomato, cherry and orange juice samples. The recoveries of the analytes in spiked samples were in the range of 96–104%.