Yttrium oxalate

Yttrium Oxalate. This compound [126476-37-7], mol wt 441.91, exists as a trihydrate, nonahydrate [7100-75-6], or... 

Yttrium oxalate is then ignited to its oxide, Y2O3. The oxide is heated at 750°C in a stream of anhydrous hydrogen fluoride to yield yttrium fluoride, YF3. Alternatively, the oxide is mixed with ammonium hydrogen fluoride NH4HF2 and heated at 400°C in a stream of dry air or helium. Yttrium metal may be produced from its fluoride either by metallothermic reduction or electrolysis. The more common metallothermic reduction involves reducing the fluoride with redistilled calcium in 10% excess over the stoichiometric amounts at elevated temperatures ... 

Step. 3b. Remove from oven, let cool, and weigh as yttrium oxalate. Take the average of replicate results. Label the carrier bottle as mg Y3+ or yttrium oxalate per mL, date, and initial. Note that the yttrium oxalate includes waters of hydration. 

Taking into consideration the method of °Sr analysis, the activity equilibrium state between °Sr and its decay product °Y is very important. This state is attained 12 days after the separation of radiostrontium [62]. The reliability of the received results of °Sr determination depends on the minimum detectable activity (MDA) [5]. The MDA should be calculated for each analysis sample. Generally, the separation of °Sr with the use of fuming HNO3, and subsequent co-precipitation of radium, lead, and barium as chromates, is used for the analysis of flora, soil, ash filters, and water samples. The fusion products (e.g., Cs) are removed by co-precipitation of the hydroxides, then transformed into yttrium oxalate, and the activity of °Y measured in a low-level proportional counter. The yield is controlled by measuring the activity of Sr (gamma emitter) added to each sample before analysis as an internal tracer [1, 46]. The accuracy of the analytical results obtained should be verified in a validation process with the use of certified reference materials (CRMs). 

The behaviour of yttrium oxalate (573 K) was [82] generally similar to Aat of the lanthanide oxalates. No carbonate could be detected, suggesting that the carbonate is less stable than the oxalate. Carbon monoxide disproportionation proceeded to about 60%, accompanied by carbon deposition. 

Drinking, raw, and Wet acid digestion addition of Sr carrier and waste water precipitation as SrC03 extraction of Yttrium precipitation of Yttrium oxalate. p-GPC (Method 973.66 7500-Sr) No data 93-99 AOAC 1990 APHA 1992... 

An alternative is to store the supernatant solution after the barium chromate scavenging precipitation for 20 days until °Y approaches equilibrium with °Sr, and then precipitate yttrium hydroxide with the Y. The hydroxide is dissolved in dilute acid, and oxalic acid is added to precipitate yttrium oxalate. The precipitate is washed and dried, promptly weighed for yield determination, and counted with a proportional detector (Sunderman and Townley 1960). To the supernatant solution from the yttrium hydroxide precipitation, ammonium oxalate is added to precipitate strontium oxalate for weighing to determine the strontium yield. The °Sr activity is calculated from the °Y count rate adjusted for °Y ingrowth into the Sr parent, °Y decay since its separation from °Sr, yttrium and strontium yields, and °Y counting efficiency. 

Figure 6-7. Scanning electron micrographs for yttrium oxide particles obtained by calcination of yttrium oxalate particles for 6h at 823 K. (a) and 1073 K (b). (Reprodueed with permission from ref. 60. Copyright 1998 American Chemical Society)...

Strontium radioisotopes in milk can be determined by making use of an ion exchange procedure. The milk sample is allowed to stand for 2 weeks to achieve a sufficient accumulation. Citrate and both yttrium and strontium carriers are added. The solution is applied onto a column of cation then anion exchangers. Strontium and yttrium are retained on the cation and anion exchangers, respectively. Yttrium is washed out from the anion exchanger with hydrochloric acid and precipitated as yttrium oxalate. After weighing the precipitate and determining the chemical yield the activity of the °Y is measured. In the presence of the yttrium oxalate is dissolved in concentrated nitric acid, and yttrium is extracted with tributyl phosphate. Lanthanum-140 remains in the aqueous phase. Yttrium is back-washed with nitric acid and precipitated as its oxalate. In an unfavorable case, i.e., when the amount of exceeds by several orders that of °Sr, the above separation procedure has to be repeated. 

A brief report" of ND work on an add yttrium oxalate, Y(H502KQ04) ,-H2O, reveals a truly remarkable structure, which includes an H5O2 ion with dyad symmetry. The symmetrical hydrogen bond has O H O = 2.436(3), and 2.446(4) A in the deuteriated crystal. The absence of significant change supports the idea that the hydrogen nucleus moves in a symmetrical potential with a sin e minimum. ... 

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