Catalytic Determination of Vanadium in Water.

Microdetermination of Vanadium(V) by Its Catalytic Effect on the Oxidation of 1-Naphthyl Red with Potassium Bromate

“…Kinetic methods based on the catalytic effect of vanadium are more sensitive and selective so it is not necessary to apply any preconcentration technique prior the determination. A number of catalytic methods have been proposed; the most of them are based on the catalytic effect of vanadium(V) on the oxidation of various organic dyes with an inorganic reagents such as bromat (1)(2)(3)(4)(5)(6)(7)(8), chlorate (9,10), peroxydisulphate (11,12), or hydrogen peroxide (13) with photometric detection. However, many of these kinetic methods, although sensitive, lack either satisfactory selectivity or rapidity.…”

Catalytic Spectrophotometric Determination of Vanadium in Seawaters Based on the Bromate Oxidative Coupling Reaction of Metol and 2,3,4-Trihydroxybenzoic Acid

“…However, the relatively high instrumental costs [6][7][8][9][10][11] and the need for preconcentration, 6,7,14 chromatographic separation, 6,7,9 extraction 8,10,13,14 or coprecipitation 11 are common disadvantages. On the other hand, catalytic methods of analysis [16][17][18][19][20][21][22][23][24][25][26][27][28] that require simple and low-cost instrumentation usually offer enhanced sensitivities with typical detection limits of 0.1 -1.0 ng ml -1 . Of these methods, the gallic acid-persulfate standard method 19,20 and its modifications [21][22][23] can detect as low as 1 ng ml -1 of V V .…”

“…On the other hand, catalytic methods of analysis [16][17][18][19][20][21][22][23][24][25][26][27][28] that require simple and low-cost instrumentation usually offer enhanced sensitivities with typical detection limits of 0.1 -1.0 ng ml -1 . Of these methods, the gallic acid-persulfate standard method 19,20 and its modifications [21][22][23] can detect as low as 1 ng ml -1 of V V . However, due to its limited tolerability of chloride ions, the modified method 23 was applied to seawaters only after evaporating the sample in the presence of concentrated H2SO4/HClO4 mixture to remove the interfering chlorides.…”

“…Of these methods, the gallic acid-persulfate standard method 19,20 and its modifications [21][22][23] can detect as low as 1 ng ml -1 of V V . However, due to its limited tolerability of chloride ions, the modified method 23 was applied to seawaters only after evaporating the sample in the presence of concentrated H2SO4/HClO4 mixture to remove the interfering chlorides.…”

Determination of dissolved vanadium in natural waters by flow injection analysis with colorimetric detection

“…Betteridge et al 1978), we elected to pursue the development of a colorimetric flow injection analysis (FIA) method for determination of dissolved V. There are a variety of calorimetric V methods described in the literature. One frequently mentioned method is the gallic acid/persulfate calorimetric technique of Fishman and Skougstad (1964). However, even when modified to give better reproducibility (Weiguo 1983) the method requires a 40-min color-development time and 5-cm cuvettes for a detection limit of 4 nM.…”