Trace cadmium determination in tap water samples using hydrazone type ligand/diphenylcarbazone and spray-assisted droplet formation-liquid phase microextraction in SQT-FAAS system

Abstract

Toxic metals are known pollutants to pose high toxicity to the environment and humans when they occur above threshold levels. In order to meet the requirements of environmental quality standards established by pertinent regulations, analytical processes that perform quick, accurate, and precise determination of such pollutants are becoming more and more important. This study offers a rapid, efficient, and sensitive method for cadmium determination in tap water samples by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS). A spray-assisted droplet formation-liquid phase microextraction (SADF-LPME) method was developed to simultaneously extract and preconcentrate cadmium ions using microliter volumes of solvent in agreement with green analytical chemistry. Hydrazone type complexing ligand and diphenylcarbazone were tried to check the complex formation efficiencies. The optimum extraction conditions were determined by comprehensive examination of the parameters affecting complexation and extraction. The limit of detection/limit of quantification values for the DPC and L-4 hydrazone ligands under optimum conditions were 0.70/2.4 mu g/L and 1.1/3.5 mu g/L, respectively. The linear dynamic range for cadmium was found to be 2.0-75 mu g/L, and the correlation coefficient (R2) was higher than 0.99. The method has been successfully applied to tap water samples, with recovery results close to 100% validating the accuracy of the method.