Phosphorus Acid digestion

Phosphorus Acid digest yellow phosphomolybdate colorimetric Acid digest yellow phosphomolybdate colorimetric Gravimetric ... 

Phosphorus and Silicon in Waters, Effluents and Sludges [e.g. Phosphorus in Waters, Effluents and Sludges by Spectrophotometry-phosphomolybdenum blue method. Phosphorus in Waters and Acidic Digests by Spectrophotometry-phosphovanadomolybdate method. Ion Chromatographic Methods for the Determination of Phosphorus Compound, Pretreatment Methods for Phosphorus Determinations, Determination of silicon by Spectrophotometric Determination of Molybdate Reactive Silicon-1 -amino-2-naphthol-4, sulphonic acid (ANSA) or Metol reduction methods or ascorbic acid reduction method. Pretreatment Methods to Convert Other Eorms of Silicon to Soluble Molybdate Reactive Silicon, Determination of Phosphorus and Silicon Emission Spectrophotometry], 1992... 

Eberlein and Kattner [194] described an automated method for the determination of orthophosphate and total dissolved phosphorus in the marine environment. Separate aliquots of filtered seawater samples were used for the determination orthophosphate and total dissolved phosphorus in the concentration range 0.01-5 xg/l phosphorus. The digestion mixture for total dissolved phosphorus consisted of sodium hydroxide (1.5 g), potassium peroxidisulfate (5 g) and boric acid (3 g) dissolved in doubly distilled water (100 ml). Seawater samples (50 ml) were mixed with the digestion reagent, heated under pressure at 115-120 °C for 2 h, cooled, and stored before determination in the autoanalyser system. For total phosphorus, extra ascorbic acid was added to the aerosol water of the autoanalyser manifold before the reagents used for the molybdenum blue reaction were added. For measurement of orthophosphate, a phosphate working reagent composed of sulfuric acid, ammonium molyb-... 

Determination of total phosphorus in lake sediments by ignition of samples in a muffle furnace at 550°C, boiling of the residue from ignition in lmol L 1 hydrochloric acid, and subsequent determination of orthophosphate gave approximately the same values as the perchloric acid digestion. 

Dobolyi and Bidlo [76] have described methods for the determination of phosphorus in lake sediments. Shulka et al. [75] investigated the interference by arsenic in the perchloric acid digestion procedure of Murphy and Riley [85] for the determination of phosphorus in sediments. Arsenite concentrations up to 20pg did not interfere but arsenate interfered. Between 1 and 45 pg arsenic g"1 was extracted from a lake sediment and in all cases the error in the determination of phosphorus due to the presence of arsenic was less than 1%. 

The second reason for acid-digestion is the determination of the total soil elemental content of, e.g. potassium, phosphorus or trace elements. This is seldom done for potassium in normal soil samples, mainly because the total K in soils is of no value as an index to the availability of K to plants, nor is it always of value in tracing the movement or accumulation of applied fertilizer K (Pratt, 1965). The unreactive soil phosphorus is obtained by subtracting the naturally leached reactive phosphorus from the total phosphorus, and a method for determining the latter by extraction with sulphuric acid and potassium persulphate is cited by Turner and FHaygarth (2000). They analysed... 

Method 6.2c. Determination of totai phosphorus in the acid digest from Method 6.1b. with finai determination by autoanaiysis... 

Elemental composition Ca 29.46%, H 0.74%, P 22.77%, O 47.04%. The compound may be identified by x-ray analysis. Calcium may be analyzed by AA or ICP spectrometry in aqueous matrix following acid digestion. Phosphorus in the aqueous solution may be determined by colorimetry (see Phosphorus). 

Elemental composition Na 19.16%, P 25.81%, H 1.68%, 0 53.34%. The compound is dissolved in water and analyzed by AA or ICP to determine its sodium content. The phosphorus is analyzed as total P by acid digestion and colorimetric method (See Phosphorus and also Phosphoric Acid). 

Phosphorus analysis is usually best accomplished via oxidative acid digestion (H2S04/ HC104) of the samples, followed by colorimetric estimation of the phosphorus as phos-phomolybdovanadate.8... 

The analysis of nitric-perchloric acid digests of feed samples for a local industry presented an early test of the ICAP analysis of organic samples. The results obtained for Association of American Feed Control OflBcials (AAFCO) feed check samples (included as quality assurance standards within the sample suite) are given in Tables V and VI. The ICAP results for iron, copper, zinc, manganese, cobalt, and potassium are all within the uncertainty limits of the certified values. While not within the uncertainty limits, the results for calcium, magnesium, sodium, and phosphorus compare with acceptable agreement for the intended application. 

The dry-ashing plus acid digestion of tea leaves (Section 1.1) and the available phosphorus extraction (Section 1.3) are contrasting procedures in regard to the acceptable precision of the determination. In one the sample is weighed to 0.1 mg ( 0.02%), whereas in the other the 5 cm3 scoop used for measuring soil, may introduce a variation of 0.2 g ( 4%). You may like to think about this. Is the sample measuring procedure appropriate for the purpose of the analysis in each case ... 

Quantitative measurement of phospholipids is rare in routine clinical practice but more common in research (e.g., in studies of dietary influences). The choline-containing phospholipids lecithin, lysolecithin, and sphingomyelin, which account for at least 95% of total phospholipids in serum, are readily measured by an enzymatic reaction sequence using phospholipase D, choline-oxidase, and horseradish peroxidase. Kit methods with this enzymatic sequence are available commercially. Before the availability of enzymatic reagents, the common quantitative method involved extraction and acid digestion with analysis of the total lipid-bound phosphorus. ... 

Ma and Rittner (1979) conelude that acid digestion is the method of choice for decomposition of organic samples for the determination of phosphorus. The senior author has found that it is important to use perchloric acid at the end of the digestion to convert all phosphorus to orthophosphate. The reaction is as follows ... 

The total content of the elemental phosphorus in soils can be extracted and determined by perchloric acid digestion followed by spectrophotometric determination. 

J.W.B. Stewart, J. Ruzicka, Flow injection analysis. Part V. Simultaneous determination of nitrogen and phosphorus in acid digests of plant material with a single spectrophotometer, Anal. Chim. Acta 82 (1976) 137. 

PP is the total phosphorus associated with particulate matter. Total phosphorus in the particulate matter is determined by either wet ashing or perchloric acid digestion methods. PP often includes inorganic forms such as phosphate sorbed onto suspended clay particles, and suspended crystalline and amorphous precipitates of PO with Ca, Mg, Al, and Fe. Inorganic phosphorus associated with PP is termed as PIP. Particulate matter is extracted with 1M HCl and filtered solutions are analyzed for orthophosphate as described above. 

Our aim in producing these tables was to provide reliable data, rather than to change the fundamental concepts of rabbit feeding. Therefore, we had to select the most relevant nutritional criteria and discard parameters such as ileal amino acid digestibility or phosphorus availability, which, though interesting, have not yet proven to be suitable in rabbit feeding due the lack of experimental data. 

Phosphorus analysis is usually carried out after perchloric acid digestion (care ) by the method of Bartlett (1959) (Section 6.2.15). Various new methods have been developed more recently, none of which has any distinct advantage over Bartlett s. However, for small samples a mixed acid method has been recommended and this may be used for routine analysis (cf. Cook and Daughton, 1981). 

Ziegler, D. and Readnour, M., Comparison of the persulphate and sulphuric acid-nitric acid digestion for analysis of phosphorus in water. Transactions of the Missouri Academy of Science 9, 144,1975. 

The problem of non-RNA organic phosphorus compounds as contaminants in the RNA fraction has been studied by Mauritzen and Stedman (75) in connection with their RNA analyses of isolated cell nuclei, where this constituent is present in very small quantities. They present extensive data concerning the degree of contamination of the RNA nucleotides with organic and inorganic phosphates following the alkaline d estion, in the ST or STS procedure, of nuclear nucleic acids. They concluded that, for accurate assay of RNA in these methods, it is necessary to convert the pentose in the RNA fraction to furfural (5,33) with acid digestion, and assay the distilled furfural by the formation of a colored product with aniline acetate. Similar data on this type of contamination of various tissue fractions is presented by Davidson and Smellie (32) (see Section II, 1, F). 

Method 2.9 Micro Determination of Phosphorus in Polymers. Acid Digestion - Spectrophotometric Method... 

This acid digestion - spectrophotometric method determines phosphorus in amounts down to 0.5% in polymers. 

METHOD 89 - MICRO DETERMINATION OF PHOSPHORUS IN POLYMERS. ACID DIGESTION - SPECTROPHOTOMETRIC METHOD. 

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