Chemistry of marine resources. 16. A new potassium reagent and its enrichment behaviour for potassium ion in sea water

A new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i.e., 1,2,4,5-tetrahydroxybenzen-O,O',O",O"'-tetraacetic acid (TTAH sub(4)) is presented. The synthetic method of TTAH sub(4), its enrichment behaviour for potassium ion in low concentration solution and seawater, and the chemical structure of its corresponding potassium salt were investigated. A mechanism which caused the uptake of potassium ion is suggested. Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex, i.e., (TTAH sub(3)K) sub(n). Thus, the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex.