Pyrocateehol violet

In indirect methods for determination of fluoride, aluminium complexes with Eriochrome Cyanine R (ECR) [58] and Xylenol Orange [59] have been applied. The sensitivity of the ECR method increases considerably in the presence of CP [60]. The complexes of scandium with Methylthymol Blue (e = 1.07-10 at 590 nm) and Pyrocateehol Violet [61] have also been recommended. 

Two methods for determining tin are presented below the phenylfluorone method and the method based on Pyrocateehol Violet. Besides, separation of tin by co-precipitation with Mn02aq., by distillation, and extraction are also described. A review of sensitive methods for determining tin based on ternary systems has been given [23]. 

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