SOLID PHASE EXTRACTION AND SPECTROPHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF THIOCYANATE IN REAL SAMPLES

摘要

A simple,selective and rapid method for solid phase extraction and spectrophotometric determination of thiocyanate using a manganese (III) tetrakis (p-sulfonatophenyl) porphyrin,[Mn (TPPS) OAC] bound to Amberlite IR-400 has been developed.The influence of pH,amount of solid phase,sample matrix,type and amount of eluting agent and flow rates i.e.variables affecting the efficiency of the extraction system were evaluated and conditions of the sample,eluting solution and active phase were optimized.The maximal capacity was found to be as 1.16 mu g mL~(-1) for 1200 mL.Thiocyanate ions can be eluted quantitatively with 8 mL 0.3 M ferric chloride.The enrichment factor was 150.The linear range of the determination is between 0.4-2.0 mu g mL~(-1) for preconcentration method with a limit of detection of 2.8 ng mL~(-1).The method has been successfully applied for determination of trace amounts of thiocyanate in tap water,saliva sample and a synthetic mixture.