Extractive spectrophotometric determination of cobalt with 5, 7 -dichloroquinolin-8-ol and rhodamine 6 G

93-94<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">A simple and sensitive method for extractive spectrophotometric determination of trace amounts of cobalt has been described. The method is based on the extraction of ternary ion-association complex viz., cobalt-5,7,-dichloroquinolin-8-o1-rhodamine 6G into toluene. The colour reaction is sensitive (ε = 4.42 × 105 l mol-1 cm-1) and is employed for the determination of 0.7 to 7.0 μg of cobalt in 100 ml of aqueous phase. The method is precise and has been applied for the determination of trace amounts of cobalt in high purity ammonium sulphate samples.