Extraction,Spectrophotometric Determination of Tungsten(VI)with 3-Hydroxy-2-[1'-phenyl-3'-(p-methylphenyl)-4'-pyrazolyl]-4-oxo-4H-1-benzopyran as Chelating Agent and its in situ Computational Studies

摘要

A simple,fast,selective and sensitive method is developed for the microdetermination of tungsten(VI)with 3-hydroxy-2-[r-phenyl-3'-(p-methylphenyl)-4'-pyrazolyl]-4-oxo-4H-l-benzopyran(HPMPPB).The reagent forms a 1:4(M:L)yellow complex in HC1 medium which is extractable into chloroform and exhibits maximum absorbance at 415-430 nm.The Beer's law holds good in tungsten(VI)concentration range of 0.0-2.0 μg mL~(-1)with molar extinction coefficient and Sandell's sensitivity of 9.936 x 104 dm3 mol”‘cm”1 and 0.0019 μg W cm~(-2),respectively at 420 nm.The proposed method is free from the interference of a large number of analytically important elements and shown to give satisfactory results in the analysis of various synthetic and industrial samples of varying composition.