A novel and simple cloud point extraction (CPE) method for detecting trace silver has been built up with flame atomic absorption spectrometry (FAAS) through adding proper amount of n-octanol into Triton X-100 resulting in an obvious decrease of the cloud point. In the method, rhodanine was chosen as chelating agent for the preconcentration of silver. The influence of major experimental parameters such as pH, chelating agent concentration, surfactant concentration, equilibration temperature and time on the extraction of silver from aqueous solutions was investigated and optimized. Under the optimal conditions, the minimum detection was 0.18 μg/L (3σ), while the preconcentration factor could reach up to 42. The well-pleasing results of standard reference sediment analysis manifested perfect accuracy and sensitivity of the method. Also, the presented method was applied to determine the trace silver in sediment and environmental water samples with satisfactory results.

Juncui Xu, Fazhi Xie, Xianming Yue, Zhengyu Li, Shixiong Geng, Zhili Dai, Shiquan Xiong