Molecularly-Imprinted Pumice as a Selective Solid-Phase Extraction Adsorbent for Kojic Acid Determination in Cosmetic Samples

Abstract

Herein, a highly sensitive molecularly-imprinted pumice (MIP-PMC) was tailored by employed the surface imprinting method and utilized as a solid-phase extraction (SPE) adsorbent for the fast and selective separation of kojic acid (KA) from cosmetic samples. The MIP-PMC was characterized in a systematic manner and found it to be a well-grown polymer layer on the PMC. The adsorption capacity of MIP-PMC was 89.9 mg/g, with an equilibrium adsorption time of 30 min. Moreover, the imprinting factor of MIP-PMC towards KA was found to be 3.28, which further demonstrated its evident selectivity for KA. Under optimized conditions, KA was successfully isolated from cosmetic products using MIP-PMC and quantified via ultraviolet-visible (UV-vis) spectrophotometry. Method validation demonstrated excellent linearity within the range of 0.04-400 mg/L, satisfactory precision (less than 5 %), and high recoveries (98.0-100.4 %). Furthermore, the method exhibited a low limit of detection (LOD) of 12.8 mu g/L with a preconcentration factor of 4. Moreover, the sensitivity of the developed method was also checked by using HPLC and the method has comparable analytical performance. The findings indicate that the integration of MIP-PMC based SPE with UV-vis spectrophotometry offers a highly efficient approach for sample pretreatment and the accurate determination of KA in real samples.