Solvent extraction, spectrophotometric determination of copper (II) from environmental samples using o-methylphenyl thiourea as a novel reagent

A simple and rapid method has been developed for solvent extraction and spectrophotometric determination of copper (II) using o-methylphenyl thiourea (OMPT) as a sensitive reagent. The basis of proposed method is formation of copper (II)-OMPT complex. Copper (II) was extracted with 0.020 mol L-1 OMPT in chloroform from aqueous solution in 0.075 mol L-1 potassium iodate. The absorbance of complex was measured at 510 nm. Beer’s law was obeyed up to 600 µg mL-1 for copper (II). The molar absorptivity and Sandell’s sensitivity of the complex were 1.0167×103 L mol-1 cm-1 and 0.0625 µg cm-2 respectively. Correlation coefficient of the method was 0.93. The stoichiometry of copper (II)-OMPT complex was 1:1 established from slope ratio, mole ratio and job’s continuous variation methods. The stability of copper (II)-OMPT complex was > 24 h. The proposed method is free from interferences from large number of foreign ions. The proposed method was successfully applied for separation and determination of copper (II) from real samples (vegetable and environmental samples), binary and ternary synthetic mixtures. Precision of method was checked by finding relative standard deviation for eight determinations that was 0.23%.

Keywords:

O-methylphenyl thiourea , environmental samples , solvent extraction , Analysis , copper , spectrophotometry