Extractive spectrophotometric determination of niobium(V) using 3-hydroxyflavone

Abstract

A simple, rapid method for the spectrophotometric determination of niobium in trace amounts is presented, employing 3-hydroxyflavone as a ligand for the complexation of the metal ion and extracting the coloured complex into chloroform from 4M HC10 4 solution. Beer's law is obeyed in the range 0.0 to 3.2 I.tg ml-1 Nb(V), with a lower working limit of 0.1 t~gml-1 Nb(V). Molar absorptivity and Sandell's sensitivity of the complex at 395 nm are 4.088 x 1041mol-lcm -1 and 0.002pg Nb(V) cm -2, respectively. The stoichiometry of the complex is established as 1:2 by Job's and mole ratio methods. The method is free from the interference of a large number of analytically important elements. The proposed system handles satisfactorily the analysis of several samples of varying complexity. The results are highly reproducible with a relative standard deviation of 0.34% for 20 btg of Nb.

Site-Specific Anchoring of a Flavonol Dye into Zeolite β Nanoparticles

“…Aluminum Chelation. Since 3-OHF molecules exhibit chelation properties with Al 35,36 and the zeolite β framework presents partially coordinated aluminum atoms, the possible formation of (3-OHF)-aluminum chelates in the dye-loaded nanoparticles has been investigated.…”

3‐Hydroxy‐2‐[1′‐phenyl‐3′‐(p‐chlorophenyl)‐4′‐pyrazolyl]‐4‐oxo‐4H‐1‐benzopyran as a spectrophotometric reagent for trace determination of tungsten(vi)

“…Various benzopyranes (chromones) and some of their derivatives [1–5] form stable and coloured complexes with many transition metal ions including tungsten, which are extractable into organic solvents. As these complexes are strongly coloured, such reagents can be conveniently applied for the trace determination of metal ions spectrophotometrically.…”

Extractive Spectrophotometric Determination of Niobium (V) Using 3- Hydroxy-2-(4'-Methoxyphenyl)-4-Oxo-4H-l-Benzopyran as a Complexing Agent

“…The highly sensitive and reliable methods for quick determination of niobium such as atomic absorption and atomic emission are not found suitable in routine analysis because of their high cost and the requirement of a separate lamp source for each element to be determined. The literature survey on the methods of extraction and spectrophotometric determination of niobium reported in the past, employing benzopyrans as complexants [3][4][5]11,14], reveal that there is still a lot more to be done regarding rapidity, selectivity and sensitivity to find their usefulness concerning the analytical chemistry of niobium. With this end in view, 3-hydroxy-2-(4'-methoxyphenyl)-4-oxo-4H-1-benzopyran(HMPB) has been used for the first time in a spectrophotometric determination system involving niobium in microgram amounts.…”

“…The methods are usually time consuming [1,[3][4][5], though sensitivity is slightly improved in a few cases. The highly sensitive and reliable methods for quick determination of niobium such as atomic absorption and atomic emission are not found suitable in routine analysis because of their high cost and the requirement of a separate lamp source for each element to be determined.…”

“…Various existing methods [1][2][3][4][5][6][7][8][9][10][11][12][13][14] of spectrophotometric determination of niobium(V) suffer from interferences from a large number of foreign ions like Ti, V, Mo, W, Pt, Re, U and Ta. The methods are usually time consuming [1,[3][4][5], though sensitivity is slightly improved in a few cases.…”