Cloud Point Extraction Using Triton X-100 at Low Temperature for Trace Analysis of Silver in Sediment and Environmental Water with Flame Atomic Absorption Spectrometry

N-octanol can dramatically decrease the cloud point of Triton X-100, a new and simple cloud point extraction (CPE) method using rhodanine as chelating agent for the preconcentration of trace level silver and determined by flame atomic absorption spectrometry(FAAS) was developed. The effect of different experimental conditions on the extraction of silver from aqueous solutions was investigated. The result showed that the cloud point of surfactant can decreased from 65 C to 36 C by adding 1.2m1 n-octanol. Under optimum conditions (pH range 3.0-5.0, 0.5ml 0.5mol/L rhodanine, 2.0ml 10% Triton X-100,equilibrium temperature: 40 C,equilibrium time: 30min). The limit of detection was 0.18 mu g/L (3 sigma) for silver and the preconcentration factor could be as high as 42. The results of standard reference sediment analysis indicated the accuracy and sensitivity of the method. The proposed method was applied to the determination of trace silver in sediment and environmental water samples with expected result.