Vanadium determination

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... 

As an example of the capabilities of a combination of INAA and RNAA using a two group separation scheme for the simultaneous determination of As, Cd, Cu, Mo, Sb, Hg, and Se (Kucera and Soukal 1993), and a single separation procedure for vanadium determination (Byrne and Kucera 1991), Table 3.8 shows results for NIST-SRM-i573a Tomato Leaves that were obtained prior to certification of this material (Kucera 1995), and later on taken into consideration for deriving the NIST certified and information values (Becker 1995, personal communication). 

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. 

R. E. Santelli, M. A. Becerra, A. S. Freire, E. P. Oliveira and A. F. Batista-de-Carvalho, Non-volatile vanadium determination in petroleum condensate, diesel and gasoline prepared as detergent emulsions using GFAAS, Fuel, 87(8-9), 2008, 1617-1622. 

Reduction of the Catalyst. During the catalytic reaction, there is a progressive reduction of the catalyst. Summarized in Fig. 4 is the change in the conversion of hydrocarbon during the catalytic tests in l butene oxidation at 120°C over Pd Og/alumina and the valence state of vanadium determined by chemical analysis. 

P. Bermejo Barrera, T. Pardinas Alvite, M. C. Barciela Alonso, A. Bermejo Barrera, J. A. Cocho de Juan, J. M. Fraga Bermudez, Vanadium determination in milk by atomic absorption spectrometry with electrothermal atomization using hot injection and preconcentration on the graphite tube, J. Anal. Atom. Spectrom., 15 (2000), 435-439. 

Other authors propose the APDC/MIBK chelation/extraction system for the vanadium determination in urine by GFAAS (Buratti et al., 1985 White et al., 1987). A detection limit of 0.4 /[Pg.534]

ICP-OES is the most practical technique for vanadium determination, with a detection limit of around 5, g/L urine. The precision is 8.5% and the recovery 98%. The urine is acidified with nitric acid (4.5 mL urine and 0.5 mL HNO3, 65%) and without further sample processing directly transferred into the nebulizer of the spectrometer. Aqueous standards are used for calibration (Schramel, 1993). 

Welch, R.M. and Allaway, W.H. (1972). Vanadium determination in biological materials at nanogram levels by a catalytic method. Anal. Chem., 44,1644. 

Vanadate, pentachloro-stereochemistry, 40 Vanadate, pentafluorooxy-stereochemistry, 50 Vanadium determination, 548... 

Vanadium determination with the graphite tube technique (Furnace method)... 

There are two commonly used spectrophotometric methods for vanadium determination. The first one involves the reaction of peroxide with vanadium(V) in sulfuric acid media, producing a reddish-brown coloration due to the formation of vanadyl sulfate (450 nm). The second method is based on the reaction of phosphoric acid and sodium tungstate with an acid vanadate solution. The product of these reactions is a yellow, soluble phosphotungstovanadic acid. 

Several sensitive and selective methods have been proposed recently for vanadium determination based on different chromogenic reagents, such as 1,5-dip-henylcarbohydrazine (1,5-diphenylcarbazide) in a slightly acid medium (531 nm), 2-(5-nitro-2-pyridy-lazo-)-5-(N-propyl-N-sulfopropylamino)phenol in a weakly acid medium (592 mn), 2-(2-thiazolylazo)-p-cresol in the presence of ascorbic acid (525 mn), and 6-chloro-3-hydroxy-7-methyl l-2-(2thienyl)-4H-chr-omen-4-one in a weakly acidic medium (425 mn). Also, the utilization of 4-(2-pyridylazo)-resorcinol (PAR) in the presence of hydrogen peroxide (542 mn, LOD 0.0028 p-gml"" ) and in the presence of cetyl-pyridinium chloride and ethylenediaminetetraacetic acid (600mn, LOD 3.0p.gml ) has been proposed. 

Applications related to vanadium determination and micellar media can also be found. Different oxidation states of vanadium have been determined at pH 5 using gallic acid in a cationic micellar solution of cetyltrimethyl ammonium bromide (CTAB). 

In order to resolve the present inconsistencies in serum and blood vanadium determination, Byrne and Versieck [81] reported a totally postirradiation radiochemical neutron activation analysis method. Their procedure was as follows After irradiating the sample for up to 12 min at a nuclear reactor neutron flux of 4 x 10 n/cm -sec the sample was transferred to a 100-mL, long-necked, silica Kjeldahl flask containing 3 mL 18 M H2SO4, 20 ji,g V carrier, and a weighed aliquot of... 

Bermejo-Barrera, P., Pita-Calvo, C., Bermejo-Marinez, F., (1991), Simple preparation procedures for vanadium determination in petroleum by atomic absorption spectrometry with electrothemal atomization. Anal. Lett., 24,447-458. 

Guidr, J.M., Snddon, J., (2002), Fate of vanadium determined by nitrcais oxide-acetylene flame atomic absorption spectrometry in unburned and burned Venezuelen crude oil, Microchem.., 73, 363-366. 

Complete the vanadium determination as described in the spectrophotometric procedure described in Method 67. 

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. 

Valerate, determination of 60-65 Vanadium, determination of 151, 228 yl chloride, determination of 350 Volatile organic compounds, determination of 112... 

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