Bulk optodes based on neutral dithiocarbamate ionophores with high selectivity and sensitivity for silver and mercury cations

Article abstract of DOI:10.1021/ac00082a019

Membranes for optically sensing Ag⁺ and Hg²⁺ based on plasticized poly(vinyl chloride) (PVC) containing a metal ion-selective ionophore, a hydrogen ion-selective chromoionophore, and lipophilic anionic sites are presented. Different dithiocarbamate ionophores have been used to develop novel optical sensors for environmental analysis. Optode membranes based on the ionophore methylene bis(diisobutyldithiocarbamate) (MBDiBDTC) reversibly respond to Ag⁺ and Hg²⁺ and show extremely high selectivities over Li⁺, Na⁺, K⁺, Mg²⁺, Cu²⁺, Cd²⁺, and Pb²⁺. The detection limit for Ag⁺ is 2.5 × 10^-9 M at pH 4.7. The dynamic range, response behavior, reversibility, and selectivity of the optode membranes are discussed.