Thiourea-based ionophores

The potentiometric detection of sulfate can be performed by Gran s plot titration of the sulfate solution with a commercially available barium-selective electrode (17), Sulfate-selective electrodes based on solid state crystals have also been reported (18), More recently, polymeric-membrane sulfate-selective electrodes have been developed using imidazole and thiourea derivatives as ionophores (19, 20),... 

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