Phosphorus, determination

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... 

B. Phosphovanadomolybdate method Discussion. This second method is considered to be slightly less sensitive than the previous molybdenum blue method, but it has been particularly useful for phosphorus determinations carried out by means of the Schoniger oxygen flask method (Section 3.31). The phosphovanadomolybdate complex formed between the phosphate, ammonium vanadate, and ammonium molybdate is bright yellow in colour and its absorbance can be measured between 460 and 480 nm. 

On silylation/germylation of 17, compounds 18 were formed, which were subsequently lithiated on phosphorus to yield 16. It appears that the success of the next step from 16 to 15 depends on different factors, but the following three parameters may be regarded as critical (1) The reaction temperature for the elimination of LiF should not exceed 80°C (2) the concentration of 16 dissolved in hexane or toluene should be about <0.1 mol L (3) the steric bulk and electronic influence of the substituent attached to phosphorus should be optimized. In the first place, the nature of the substituent at phosphorus determines the structures of the precursors 16. This has been demonstrated by a study of a structure-reactivity... 

Table 12.9 compares results for phosphorus determinations in sediments obtained by methods I and II. 

Inorganic quantitative analysis of sugar cane juice, vinasse, and molasses. 1. Calcium, magnesium, potassium, sulfur and phosphorus determination in single ex- SO099 tract. An Esc Super Agr Luiz Dr Queiroz Univ Sao Paulo 1972 29 5. 

Hycel Phosphorus Determinations Publikation von Hycel Inc., Houston, Texas. 

In ICP-MS a multi-element tuning solution is applied for the mass calibration of mass spectra. Figure 6.3 shows the mass spectrum for phosphorus determination at m/z = 31. In this case, the mass calibration was performed with the aid of a solution of a phos-phorus/sulphur mixture. From the known masses of the isotopes of the atomic ions, the masses of the polyatomic ions occurring were determined and identified in accordance with the isobaric polyatomic ions (15N160+ and 14N16OH+). Mass accuracy is the deviation of experimental determined mass of an atomic, polyatomic, cluster, molecular or fragment ion from the exact mass of species expected. Polyatomic, cluster and molecular ions were calculated from the atomic masses (see Appendix I), the mass accuracy is usually presented in ppm. 

Figure 9.22 Calibration gel for phosphorus determination in proteins ( ) ID gel of ovalbumin and bovine serum albumine for different phosphorus amount and (b) transient signals of P in protein spots (and blank) in ID gel of ovalbumin measured by LA-ICP-SFMS. (j. S. Becker et af,). Anal. At. Spectrom., 19, 1236 (2004). Reproduced by permission of the Royal Society of Chemistry.)...

If arsenate and phosphate are present together, the total arsenic and phosphorus is first determined, the arsenic is then removed with hydrogen sulphide and the phosphorus determined alone.7... 

Thomson-Bulldis, A., and Karl, D. M. (1998). Application of a novel method for phosphorus determinations in the oligotrophic North Pacific Ocean. Limnol. Oceanogr. 43, 1565-1577. 

Phosphorus exists mostly in the phosphate form in the general environment. The levels of phosphorus determined in most environmental samples are reported as total phosphorus and do not distinguish between elemental phosphorus and its compounds. However, elemental phosphorus is far more toxic than other oxidized phosphorus states (oxides and acids of phosphorus). This profile reports the level of elemental phosphorus and not total phosphorus in environmental samples. 

Kotlash, A.R. and B.C. Chessman. 1998. Effects of water sample preservation and storage on nitrogen and phosphorus determinations Implications for the use of automated sampling equipment. Water Res. 32 3731-3737. 

Bottcher, C. S. F., van Gent, C. ML, and Prus, C. (1961) A rapid and sensitive submicro phosphorus determination, Anal. Chim. Acta 24, 203-204. 

The incor poration of phosphorus. Enzyme preparations from oxidized trypsinogen of varying degrees of hydrolytic activity were allowed to react with diisopropylfluorophosphate (DFP) and the amounts of incorporated phosphorus determined. Irrespective of the activity values reached after complete activation, 1 mole of phosphorus per mole (24,000 gm) of protein was incorporated. A partially activated sample, having approximately 3 % activity as compared with 25 % on maximum activation, contained only 0.17 mole of phosphorus. After complete activation this value increased to 1 mole (Table XXV). 

Ketchum B. H., Corwin N., and Keen D. J. (1955) The significance of organic phosphorus determinations in ocean waters. Deep-Sea Res. 2, 172-181. 

The title, "The Determination of Phosphorus, for example, would interest the present author, but at once questions arise. In what kind of material is the phosphorus determined Is a separation of the element necessary If so, what kind of method is applicable Is a colorimetric method of measurement used If so, what is the color-forming reagent If it is ammonium molybdate, is the system measured molybdophosphoric acid, molybdovanadophosphoric acid, or a heteropoly blue If the latter, what are the reductant and the conditions of reduction To the extent that the title does not answer these and other similar questions, the summary should. 

The compounds 8 and 10 are formed by the reaction of IS2Sip2 with two equiv [LiEH2(DME)] (E = P, As DME = 1,2-dimethoxyethane) they show no tendency to eliminate LiF in THF solution, surely because of the inherent strength of the Si-F bond. Silylation/germylation of 8 furnished the compounds 9 and 11, respectively, which were subsequently lithiated on phosphorus and arsenic to yield 1 and 3, respectively. In the first instance, the nature of the substituent at phosphorus determines the structures of the precursors 1 and 3, respectively. This has been demonstrated by a study of a structure-reactivity relationship for several compounds 1 [6]. The latter investigation... 

Physica) tests for explosives, 65 Phosphorus, dark red, detection of, in match compositions- Dusart and Bloudlot a method, 133 Mitscherlich s method, 134 detection of white in matches— Aronstrin s method, 139 general remarks, 100, 140 Schcnck and ScharfT s.method, 138 Thorpe method, 140 Van lujk a method, 140 Phosphorus, determination of percentages of white and red in amorphous phosphorus, 100... 

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