Abstract: A novel flow injection-solid phase oxide collection-flame atomic adsorption spectrometry(FAAS) was developed for the determination of trace silver in water samples using sodium hydroxide as precipitating reagent and silica beads as adsorbent. Silver was precipitated in form of oxide and then collected on solid phase surface of silica beads packed micro-column as oxide collector. The silanol groups and surface charges on the surface of silica beads contribute to precipitation adsorption of Ag2O. The precipitate was afterwards quantitatively eluted by 10%(volume fraction) nitric acid with the detection by FAAS. By loading 5.4 mL sample solution, an enrichment factor of 25.5, a detection limit(3σ) of 0.6 μg/L and a sampling frequency of 50 times/h were achieved, along with a linear range within 2—150 μg/L and a precision of 2.0% RSD at the 40 μg/L level(n=11). The present procedure was applied for the determination of silver by spiking recoveries in tap water, river water, well water, snow water and spring water, and the spiking recoveries were 93.3%, 89.5%, 96.6%, 108.4% and 102.8%, respectively.

Key words: Flow injection, Solid phase oxide adsorption/collection, Silver oxide, Flame atomic adsorption spectrometry