A Green Approach for Micro Determination of Silver(I) in Water and Soil Samples Using Vitamin C

A cloud point extraction/solvation method (CPE-SM) based on the use of vitamin C as a chelating agent was developed for the separation and determination of silver in environmental samples. TritonX-100 was used to extract silver ions in aqueous solutions after forming solvation species with vitamin C in the presence of salting-out (0.5 M KNO3) at 90 °C for 10 min. This study evaluated the main parameters affecting the CPE-SM method, such as the kind and concentration of the salting-out, organic reagents, silver ion, temperature, heating time, and volume of surfactant. Under the optimized experimental factors, the calibration curve was linear in the range (0.1- 10 μg l-1). The relative standard deviation (RSD) was 1.1-2.9% for n:5 at 1,4,9 μg l-1, a low limit of detection (LOD), and a limit of quantification (LOQ) of 0.035, 0.116 μg l-1, respectively. The accuracy of the method was evaluated by two independent techniques (flame atomic absorption spectrometry-FAAS, and spectrophotometry-using dithizone as a complexing agent). The CPE-SM technique was used to preconcentrate and determine the silver ions in river water, tap water, and soil samples, and the results were favorable and good.