Sorption Preconcentration Of Silver For Atomic Absorption Analysis And Antibacterial Properties Of The Acid-Modified Clinoptilolite – Ag Composite

Sorptive properties of the acid-modified Transcarpathian clinoptilolite towards Ag(I) were studied under dynamic conditions. It was found that the most effective acid-modifier is 1 M HNO3 solution. The sorption capacity value of H-clinoptilolite under the optimal conditions is 6.15 mg of Ag per 1 g of zeolite. The solid-phase extraction procedure with acid-modified clinoptilolite was used to pre-concentrate trace amounts of silver ions in aqueous solutions and then finally to determine them by the atomic absorption method. Due to the acceptable recoveries (≥ 98 %) and RSD values (2.3-4.7 %) for tap and lake water, the developed method can be successfully applied for the determination of trace amounts of silver ions in the presence of major components of water. It was established that the initial form of clinoptilolite has a better antibacterial effect against E. coli than the H-form. However, antagonistic activity against S. aureus was lower than against E. coli in both forms. The combination of different forms of clinoptilolite with Ag(I) increases their antibacterial activity.