Green and deep eutectic solvent microextraction method for faas determination of trace level cadmium in water samples using multivariate strategic approach

Abstract

An innovative green, deep eutectic solvent microextraction (DES-ME) approach was developed for the preconcentration of trace level cadmium (Cd) in fresh canal and wastewater samples prior to flame atomic absorption spectrometry (FAAS) determination. The Cd was complexed with ammonium pyrolidine dithiocarbmate (APDC) to enhance the extraction capability in the deep eutectic solvent (DES). DES exhibits similar physico-chemical properties of the traditionally used ionic liquids, but is less costly, environmentally friendly, and offers a green alternative to conventional ionic liquid extraction. Separation of the metal-enriched DES from the aqueous medium can be induced by using the Triton X-114 surfactant. The metal-enriched phase was subjected to FAAS using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of the experimental factors for the recovery of metal ions under study. The results showed that the pH, volume mixing ratios of the DES, and their interaction are the most statistically significant variables. Under the optimized experimental conditions, the limit of detection was found to be 0.504 μg L-1 and the enhancement factor was 51. The validity and accuracy of proposed method were checked by the analysis of real water samples using the standard addition method and the TM-28.3 Fortified Water sample. The proposed method was successfully applied to the trace level determination of Cd in canal water and wastewater samples.