Acid ammonium oxalate

Some typical and preferred heavy and trace element concentrations for soils and municipal composts are shown in Table 5.3. The levels in soils are typical for dilute aqueous extractants such as 0.05 M EDTA, 0.5 M acetic acid, hot water for boron, and, for molybdenum, Tamm s reagent (acid ammonium oxalate Reisenauer, 1965). Tables in the literature often give total values obtained spectrographically, by XRF, or by extraction with hot... 

Aquo-pentammino-cobaltic Oxalate, [Co(NH8)5H20]2(C204)3. 1HS0, is prepared from chloro-pentammino-cobaltie chloride. The finely powdered chloride is heated with water and dilute aqueous ammonia, the deep red liquid is filtered, and the filtrate cooled and saturated with oxalic acid. Ammonium oxalate in aqueous solution is then added to complete the precipitation of the salt, and the residue is collected on a filter, washed free from the chloride with water and finally with alcohol.2 The substance does not lose water if kept over concentrated sulphuric acid, but if heated to 100° C. it decomposes. 

Glyoxal, 40 % Solution Glyoxal, 40 % Solution Oxalic Acid Ammonium Oxalate Cyanogen Ferrous Oxalate Cyanogen... 

Schwertman, U. (1964) The differentiation of iron oxides in soils by a photochemical extraction with acid ammonium oxalate. Z. Pflanzenernahr. Dueng. Bodenk., 105,194-201. 

Calcium (II), Ca+2 Ammonium carbonate Dilute sulfuric acid Ammonium oxalate... 

Davidson, C. M., Hursthouse, A. S., Tognarelli, D. M., Ure, A. M., and Urquhart, G. J. (2004). Should acid ammonium oxalate replace hydroxylammonium chloride in step 2 of the revised BCR sequential extraction protocol for soil and sediment Anal. Chim. Acta 508, 193—199. 

Correlation coefficients shoving the relation of Zn to Fe, Mn, organic carbon and particle size in sediments extracted vith either acetic acid, hydroxylamine hydrochloride in 0.01 nitric acid, ammonium oxalate, ammonium acetate, or concentrated nitric acid. English data vcre log transforried for statistical analysis. 

Arsenic in soilds has been fractionated by Jackson s T28) procedure for soil phosphorus (15. 27). In this laboratory, a modification of Jackson s procedure is being used on sediment solids. A series of 1 molar solutions of NH4CI, NH4OH, acid ammonium oxalate (29) and HCl are used in sequence. The chloride fraction, or exchangeable fraction, contains weakly adsorbed, coulombically bound arsenic. The hydroxide fraction, contains iron and aluminum arsenate precipitates and surface precipitates (i.e. adsorbed arsenic species having both chemical and coulombic bonding to oxide surfaces). The oxalate, or reductant soluble fraction, contains arsenic occluded in amorphous weathering products. The acid, or calcium, fraction contains arseno-apatites. 

Oxides of manganese and iron. Acidified hydroxylamine hydrochloride releases metals from the manganese oxide phase with minimal attack on the iron oxide phases. Amorphous and crystalline forms of iron oxides can be discriminated between by extracting with acid ammonium oxalate in the dark and under UV light, respectively. 

Technetium metal is also clectrodeposited almost quantitatively from dilute solutions of TcOj in acidic ammonium oxalate solutions. Films up to 18 mg/cm were deposited as dense adherent coatings on copper, gold, silver, and platinum cathodes at a current density of 1.3 A/cm . At an oxalate concentration of 0.7 M. the molarity of H2SO4 required for the deposition of technetium metal varied between 0.45 M with a copper cathode and 1.90 M with a platinum cathode. At lower molarities of H2SO4 technetium was deposited as oxide (Table 9.1.A). 

Hughes, J. C. (1982). High gradient separation of some soil clays from Nigeria, Brazil and Columbia. I. The interrelationships between iron and aluminium extracted by acid ammonium oxalate and carbon. /. Soil Sci. 33, 509-519. 

Solubility of Neutral Ammonium Oxalate in Aqueous TioNs OF Acid Ammonium Oxalate. 

Karimian and Cox (1978) found no correlation between plant Mo uptake and soil Mo extracted by anion resin or acid ammonium oxalate. Lombin (1985) found better correlations for either 0.1-N NaOH or acid ammonium oxalate extraction and Mo uptake by peanuts than for anion-resin extraction and Mo uptake. Sherrell (1989) concluded that the resin method was not accurate enough for diagnosis of Mo deficiency in the pastoral soils of New Zealand, although the resin method was more useful than the ammonium oxalate method. 

Molybdenum, both the inorganic salt and that contained in Mo-enriched sludge, and lime (CaO) were applied to a sandy loam soil in a greenhouse to evaluate the influence of soil pH on plant uptake and extractability of Mo (Pierzynski and Jacobs, 1986a). Molybdenum in com (Zea mays L.), soybean, and alfalfa increased with increases in soil pH. Molybdenum extracted with AB-DTPA also increased with increasing soil pH, but values for Mo extracted with acid ammonium oxalate were not influenced by soil pH. Plant Mo was more closely related to values obtained by the AB-DTPA method than those by the ammonium oxalate method. Including soil pH in the multiple-regression analyses of plant Mo or extractable soil Mo improved predictions in 17 of 24 prediction equations. 

For assessing the availability of Mo in alkaline soils, various extractants have been used, including water-saturation extract, hot water (Lowe and Massey, 1965), acid ammonium oxalate (Grigg, 1953), ammonium carbonate (Vlek and Lindsay, 1977), and ammonium bicarbonate-DTPA (Soltanpour, 1985), as well as the bioassay procedure using A. niger (Mulder, 1948). 

Acid ammonium oxalate, buffered to pH 3.3, has commonly been used to extract plant-available Mo from a soil. Its content in a majority of Indian soils has ranged between 0.10 and 0.8 tgg" . However, a few alluvial and... 

Major element concentrations in the acid ammonium oxalate extraction... 

Sr resin Selective resin Sr, Pb Nitric acid, ammonium oxalate... 

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