Arsenazo III 2,2-

Only slightly less accurate ( 0.3—0.5%) and more versatile in scale are other titration techniques. Plutonium maybe oxidized in aqueous solution to PuO " 2 using AgO, and then reduced to Pu" " by a known excess of Fe", which is back-titrated with Ce" ". Pu" " may be titrated complexometricaHy with EDTA and a colorimetric indicator such as Arsenazo(I), even in the presence of a large excess of UO " 2- Solution spectrophotometry (Figs. 4 and 5) can be utilized if the plutonium oxidation state is known or controlled. The spectrophotometric method is very sensitive if a colored complex such as Arsenazo(III) is used. Analytically usehil absorption maxima and molar absorption coefficients ( s) are given in Table 10. Laser photoacoustic spectroscopy has been developed for both elemental analysis and speciation (oxidation state) at concentrations of lO " — 10 M (118). Chemical extraction can also be used to enhance this technique. 

As the result of the performed investigations was offered to make direct photometric determination of Nd microgram quantities in the presence of 500-fold and 1100-fold quantities of Mo and Pb correspondingly. The rare earth determination procedure involves sample dissolution in HCI, molybdenum reduction to Mo (V) by hydrazine and lead and Mo (V) masking by EDTA. The maximal colour development of Nd-arsenazo III complex was obtained at pH 2,7-2,8. The optimal condition of Nd determination that was established permit to estimate Nd without separation in solution after sample decomposition. Relative standard deviations at determination of 5-20 p.g of Nd from 0,1 g PbMoO are 0,1-0,03. The received data allow to use the offered procedure for solving of wide circle of analytical problems. 

The results of the complexation study of Cu(II), Pb(II), Zn(II), Fe(III), Hg(II), Cd(II), Sn(IV), Zr(IV), Ti(IV) with arsenazo III, sulfonazo III, SPADNS, Eriochrome T, Acid Chrome Dai k Blue, Xylenol Orange, Methyl Thymol Blue, Pyrocatechol Violet, Chrome Azurol S, Eriochrome Cyanin R, Basic Blue K, Methyl Violet, Brilliant Green, Rhodamine C and Astraphoxin in solid phase. The obtained data ai e used for the working out of a new method of metal determination. 

Arsenazo (III) to produce a colored complex, which can be determined with standard colorimetric methods. Arsenic compounds are highly toxic. 

Hirose and Sugimura [89] investigated the speciation of plutonium in seawater using adsorption of plutonium (IV)-xylenol orange and plutonium-arsenazo (III) complexes on the macroreticular synthetic resin XAD-2. Xylenol orange was selective for plutonium (IV) and arsenazo (III) for total plutonium. Plutonium levels were determined by a-ray spectrometry. 

Azo dyes contain an azo link between two aromatic rings possessing a orthohydroxy group. The most important reagents include PAN, PAR, and Arsenazo III and generally they offer high sensitivity for the majority of transition metals. 

Thorium coprecipitated from acidified sample with Fe(OH)3, clean-up Th by selective solvent extraction, coprecipitated with Al(OH)3 and develop color by Arsenazo III reagent. After color development, coprecipitate Th with LaF3. 

Protactinium is separated by solvent extraction and anion exchange processes by using sulfate solutions. After chemical separation, the protactinium salts are ignited to a pentoxide, Pa205, which may be converted into an arsenazo(III) complex. The absorbance of the solution is measured at 630 nm with a spectrophotometer. Protactinium-231 is an alpha emitter and also forms photons at 300 KeV, which can be measured by various radioactive counters and spectrophotometric techniques. Protactinium also can be measured by neutron activation analysis. 

X-ray structure showed octahedral Yb06 groups to be present.251 Ion exchange, dialysis and spectrophotometry using Arsenazo-III have been used to study the hydrolysis of the hydrated Y3+ ion at 10-5 to 10-2 M and pH 1 to 9. Mono- and poly-nuclear complexes were present, and Kx for Y(OH)-aq was 2.52 x 106.252... 

Table 6 merely lists reagents such as xylenol orange (44) and arsenazo(III) (45) which are often used absorptiometrically, and morin (46) used also in fluorimetric procedures, together with other reagents for the commoner metals. It would be pointless to give practical details of procedures which can be found in standard text books3-7,22,30,33 or specialist publications.76,77 IUPAC have... 

Rhodamine,b rhodamine B,b dithizoneb Arsenazo III, querdtinc Dithizone,b oxine,b morinc... 

Arsenazo III, alizarin S, oxine Furildioxime PAN,b NaDDC Diphenylurea, TPT Alizarin S... 

Brilliant green,b rhodamine B,b dithizone,b NaDDCb Arsenazo III. thorin... 

Arsenazo III - [ARSENIC COMPOUNDS] (Vol 3) -for plutonium analysis [PLUTONIUM AND PLUTONIUM COMPOUNDS] (Vol 19)... 

Finally it should be noted that while classical methods for analysis tend to be little used, there are certain colorimetric methods for calcium which are of value. Thus, determinations with arsenazo III involve a detection limit of 10-7 mol dm 3. Calcium may also be determined using the photoproteins aequorin and obelin, which emit light on interaction with Ca2+ and have detection limits around 5 x 10-8 mol dm-3. These methods have had some interesting in vivo applications. 

Two moles of Ca2+ appear to bind to the protein per phosphorylation site. Binding of one Ca2+ causes a conformational change followed by binding of Ca2+ to a second site. The use of Ca2+ electrodes or arsenazo III indicator shows the ratio Ca2+/ATP= 1.82 0.13 in the presence of saturating Ca2+. The ratio decreased with increasing pH (with an apparent pK = 7.9), and at temperatures over 30 °C. It was also dependent upon Ca2+. Thus the stoichiometry appears to vary with the physiological conditions due to pump slippage .146... 

M. Zenki, K. Minamisawa and T. Yokoyama, Clean analytical methodology for the determination of lead with Arsenazo III by cyclic flow-injection analysis, Talanta, 68 (2005) 281-286. 

Kerr el. al. [307] employed high performance liquid chromatography for the determination of uranium in groundwaters. The sample was passed through a small reversed phase enrichment cartridge, to separate the uranium from the bulk of the dissolved constituents. The uranium was then back flushed from the cartridge onto a reversed phase analytical column. The separated species were monitored spectrophotometrically after reaction with arsenazo(III). The detection limit was in the 1-2gg L 1 range with a precision of approximately 4%. 

The other metal ions that exhibited an appreciable reaction with Arsenazo(III) at 650nm under the separation and detection conditions used, were iron(III), zirconium(IV), thorium(IV) and the lanthanides. The lanthanides, iron(III) and zirconium(IV) were eluted at or near the solvent front before uranium(VI) and thorium(IV) was eluted after uranium(VI). 

Earlier techniques for measuring cytosolic free Ca2+ (1-2) such as the luminescent photoprotein aequorin, the absorbance dye arsenazo III and Ca2+-sensitive microelectrodes, all required microinjection or impalements, and were therefore applied mainly to giant cells. Later, photoproteins have been loaded with various reversible permeabilization procedures (3), but the largest expansion in the range of cell types in which Ca2+ signals can be quantified has come from the development of new fluorescent indicators that can be loaded using hydrolyzable esters. Currently four fluorescent indicators are used frequently quin-2, fura-2, indo-1 and fluo-3. 

Fig. 1.22. Direct injection of aluminium processing solution. Conditions Supelcosil LC-18-DB column gradient programme at a flow-rate of 1.0 ml/min from 1.05 M HIBA to 0.4 M HIBA over 10 min. and held at 0.4 M for 5 min. modifier, 1-octanesulphonate at 0.01 M (A), eluents at pH 4.5 (B), eluents at pH 3.8 detection at 658 nm after post-column reaction with Arsenazo III sample injected, 50 pi sample dilution, (A) 10 ml to 100 ml,...

Element Atomic absorption sensitivity (ppm/1% absorption) Spectrophotometric sensitivity of Th-Arsenazo III colour reaction (pg/cm2) Minimum determinable concentration (ppm in original sample) Flame OES OES emission (photoelectric) (photographic) ... 

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