Vanadium analysis

Monien and Stangel [598] studied the performance of a number of alternative chelating agents for vanadium, and their effect on vanadium analysis, by atomic absorption spectrometry with volatilisation in a graphite furnace. Two promising compounds were evaluated in detail, namely 4-(2-pyridylazo) resorcinol in conjunction with tetraphenylarsonium chloride and tetramethylenedithiocar-bamate. These substances, dissolved in chloroform, were used for extraction... 

Ion exchanger colorimetry has been used as a sensitive and rapid method for vanadium analysis by immobilization of 2[2-(3-5-dibromopyri-dyl)azo]-5-dimethylaminobenzoic acid onto an ion exchanger resin AG 1X2 [75]. Solid phase fluorimetry can be useful for the analysis of very dilute solutions in water analysis or trace metal determination thus a chelating 8-(benzene-sulfonamido)quinoline, immobilized on Amberlite XAD2 support, has been used for the spectrofluorimetric determination of Zn(II) and Cd(II) [76]. 

Ion exchanger colorimetry has been used as a sensitive and rapid colorimetric method for vanadium analysis. An immobilized organic extractant exhibits high selectivity toward vanadium (V), for example, 2[2-(3,5-dibro-... 

Pipette aliquots of the test solution into two separate volumetric flasks. Retain one flask for the determination of nickel and iron. To the other flask add aluminum interference suppressant for vanadium determination (refer to Table I) and dilute up to mark with dilute nitric add (3 % V/V). Similarly, prepare a reagent blank solution for vanadium analysis. 

Vanadium content NF M 07-027 ASTM D 1548 Dissolving ash in acid and colorimetric analysis... 

For a two-factor system, such as the quantitative analysis for vanadium described earlier, the response surface is a flat or curved plane plotted in three dimensions. For example. Figure 14.2a shows the response surface for a system obeying the equation... 

This experiment describes a variable-size simplex optimization of the quantitative analysis of vanadium as... 

The ash analysis receives special attention because of certain trace metals in the ash that cause corrosion. Elements of prime concern are vanadium, sodium, potassium, lead, and calcium. The first four are restricted because of their contribution to corrosion at elevated temperatures however, all these elements may leave deposits on the blading. 

Samples Analyzed by Inductively Coupled Plasma (ICP) Metals — Where two or more of the following analytes are requested on the same filter, an ICP analysis may be conducted. However, the Industrial Hygienist should specify the metals of interest in the event samples cannot be analyzed by the ICP method. A computer print-out of the following 13 analytes may be typically reported Antimony, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Manganese, Molybdenum, Nickel, Vanadium, Zinc. Arsenic — Lead, cadmium, copper, and iron can be analyzed on the same filter with arsenic. 

Cells used for high-temperature measurements in furnaces often consist of silica sample tubes, supported by thin vanadium sleeves. The key to the analysis is whether it is possible to have a container that scatters in a sufficiently predictable way, so that its background contribution can be subtracted. With the current neutron flux available from both pulsed and reactor sources, sample volumes of... 

Tin plate, thickness of tin coating on, determination by x-ray spectrography, 148, 149, 157, 158 Tissues, determination of dry weight by absorptiometry, 297-300 Tissue sections, biological, determination of mineral elements in, 301-305 Titanium, as internal standard in vanadium determination, 188 determination by x-ray emission spectrography, 222, 329 trace analysis by x-ray emission spectrography, 163, 225-229 Topaz, as analyzing crystal, 116-118, 220, 318-327 Total reflection, 112, 117... 

Vanadium, determination by x-ray emission spectrography, 188, 329 trace analysis by x-ray emission spectrograph y, 228, 229... 

Vanadium coordination compounds classification and analysis of crystallographic and structural data. C. E. Holloway and M. Melnik, Rev. Inorg. Chem., 1985,7, 75 (185). 

Some haloperoxidases contain vanadium and a review of vanadium peroxidases has been given (Butler 1998). The structure of the vanadium enzyme in the terrestrial fungus Cur-vularia inaequalis has been determined by x-ray analysis (Messerschmidt et al. 1997), and the apochloroperoxidase possesses, in addition, phosphatase activity that can be rationalized on the basis of the isomorphism of phosphate and vanadate (Renirie et al. 2000). 

In agreement with the results from the characterization, the SCR activity of VOx/Zr02 also depends only on the V-content, not on the method used for catalyst preparation. The marked increase in SCR activity with the V-content shows that only specific vanadium configurations are active. Although we assess the V=0 modes associated with these active configurations, IR analysis did not specify the structure of active polyoxoanions. 

Byrne AR, and Kucera J (1991) Radiochemical neutron activation analysis of traces of vanadium in biological samples A comparison of prior dry ashing with post-irradiation wet ashing. Fresenius f Anal Chem 340 48-52. 

Byrne AR, and Versieck J (1990) Vanadium determination at the ultratrace level in biological reference materials and serum by radiochemical neutron activation analysis. Biol Trace Elem Res 27 529-540. 

Kucera J, and Soukal L (1998) Low uncertainty determination of manganese and vanadium in environmental and biological reference materials by instrumental neutron activation analysis. Fresenius J Anal Chem 360 415-418. 

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