Determination of Trace Amounts of Vanadium by Kinetic‐Catalytic Spectrophotometric Methods

Abstract

Kinetic-catalytic spectrophotometric methods were proposed for the determination of trace amounts of vanadium element as vanadium(IV) and/or V(V) ions. The vanadium(IV) as VO 2＋ ion and/or vanadium(V) as 3 VO -ion showed a catalytic effect on the kinetic reactions between a color reagent such as methylthymol blue (MTB) or SPADNS and bromate in acidic media. The rate of decrease in the absorbance of the reagent MTB at 440 nm or SPADNS at 510 nm was proportional to concentration of V(IV) and/or V(V) ions in the solution. The linear ranges for determination of vanadium were obtained in the range of 1.0-150 and 5.0-100.0 µg/L by the fixed-time and slope methods, respectively, with using MTB as reagent. In the presence of SPADNS as reagent, the calibration curves were made in the amplitude 1.0-200.0 and 5.0-150 µg/L of vanadium ion by the fixed-time and slope methods, respectively. Using fixed-time method, the limits of detection were obtained to be 0.5 and 0.7 µg/L of vanadium in the presence of MTB and SPADNS as reagents, respectively. Detection limits of vanadium by slope method and reagents of SPADNS and MTB were obtained to be 3.5 and 3.8 µg/L of vanadium, respectively. The proposed methods were applied successfully to determination of vanadium in synthetic and real samples.

An efficient and selective flourescent optode membrane based on 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione as a novel fluoroionophore for determination of cobalt(II) ions

“…In addition, the nature of plasticizer is well-known to influence largely the measuring concentration range of the solvent polymeric sensors as well as their selectivity coefficients [12][13][14][15][16][17][18][19][20][21][22][23][29][30][31][32][33][34][35][36][37][38]52].…”

“…Thus, due to the urgent need for specific monitoring of Co 2+ ion in many industrial, environmental medicinal and food samples, there have been a number of recent reports on potentiometric cobalt ion-selective electrodes in the literature [29][30][31][32][33][34][35][36][37][38]. However, most of these electrodes possess either one, two or, in some cases, all of the following drawbacks: (1) narrow working concentration range, (2) high limit of detection and (3) significant interferences from many cations.…”

A novel indicator reaction for the catalytic determination of V(V) at ppb levels by the kinetic spectrophotometric method

“…In another work [22] researchers proposed a kinetic-catalytic spectrophotometric method for the determination of trace amounts of V(IV) and V(V) ions. The vanadium (IV) as VO 2+ ion and vanadium(V) as VO 3 -ion showed a catalytic effect on the kinetic reactions between methylthymol blue (MTB) and bromate in acidic media.…”

A novel indicator reaction for the catalytic determination of V(V) at ppb levels by the kinetic spectrophotometric method

“…In another work [22] researchers proposed a kinetic-catalytic spectrophotometric method for the determination of trace amounts of V(IV) and V(V) ions. The vanadium (IV) as VO 2+ ion and vanadium(V) as VO 3 -ion showed a catalytic effect on the kinetic reactions between methylthymol blue (MTB) and bromate in acidic media.…”