A novel UA-CPME-FAAS method for simultaneous determination of Pb(II), Cd(II), and Cu(II) in grape and pomegranate samples using a bis(phthalimidoethyloxy)anthraquinone ligand

Abstract

In this study, a novel ultrasound-assisted cloud point microextraction (UA-CPME) method coupled with flame atomic absorption spectrometry (FAAS) was developed for the simultaneous determination of Pb(II), Cd(II), and Cu(II) ions in fruit samples. The extraction strategy employed synthesized 1,8-bis(phthalimidoethyloxy)anthraquinone ligand, used for the first time in a CPME system. Under optimized conditions, the metal-ligand complexes were efficiently extracted into the surfactant rich phase using the nonionic surfactant Triton X-100 at mild temperature and pH. The analytical performance of the method was remarkable, with low detection limits (0.6 µg L⁻¹ for Pb, 0.5 µg L⁻¹ for Cd, and 0.4 µg L⁻¹ for Cu), wide linear ranges (Pb: 0.7–350, Cd: 0.7–400, Cu: 0.5–400 µg L⁻¹), and excellent recoveries ranging from 95.6 % to 99.4 % with relative standard deviations below 2 %. The method was successfully applied to real grape and pomegranate juice samples, high recoveries and demonstrating minimal matrix effects. Matrix-matched calibration was not required, confirming the method’s robustness and selectivity across different sample types. Furthermore, the use of a non toxic surfactant and elimination of organic solvents highlight the green and eco friendly nature of the method. Overall, the proposed UA-CPME-FAAS approach offers a simple, sensitive, cost effective, and environmentally sustainable solution for trace level multimetal analysis in complex food matrices such as fruit based samples.