Phosphorus, test for

Cerium in Plants and Animals. Professor Alfonso Cossa, finding the rare earths of the ceria series to be present in many apatites, and realizing the close association in nature between these earths and calcium and phosphorus, tested for them and detected their presence in bone (66). He also detected them in the ash of barley, beech wood, and tobacco. With the aid of C. Schiapparelli and G. Peroni of the University of Turin, he demonstrated their presence in human urine (66, 67, 68). 

Trichloroethanoic acid, CCI3COOH. A crystalline solid which rapidly absorbs water vapour m.p. 58°C, b.p. 196-5" C. Manufactured by the action of chlorine on ethanoic acid at 160°C in the presence of red phosphorus, sulphur or iodine. It is decomposed into chloroform and carbon dioxide by boiling water. It is a much stronger acid than either the mono- or the dichloro-acids and has been used to extract alkaloids and ascorbic acid from plant and animal tissues. It is a precipitant for proteins and may be used to test for the presence of albumin in urine. The sodium salt is used as a selective weedkiller. 

Soil pH is easily tested for and determines the availability of nutrients and the success of white clover. Very acid soils (below pH 5.0) will cause a deficiency of the trace elements iron, boron, copper and molybdenum and conversely will cause injury to plant growth by increasing the availability of aluminium and manganese to toxic levels. Over-liming, on the other hand, which can raise the pH above 6.5, will reduce the availability of certain essential elements such as phosphorus, manganese and boron. 

The product is tested for the presence of phosphorus (PC13) by decomposing a few drops with a little warm water and evaporating the solution in a porcelain capsule. The residue is twice evaporated with concentrated nitric acid or with bromine water and is finally tested for phosphoric add in the usual way. If phosphorus is detected, the material should again be distilled with a few drops of glacial acetic acid. 

The amount transformation process is illustrated with data for chlorpyrifos in the flame photometric detector, phosphorus mode, and shown in Table VI. Level 1 transformations were calculated where the amount power was increased by 0.03 units for each step. At an amount power of 0.20 the F statistic of 32.7 showed a minimum but at a confidence level of 95% did not satisfy the F test for linearity. Power steps changed by only 0.01 and 0.001 units in the vicinity of the minimum were then calculated as shown in levels 2 and 3. The best linearity was found in this case at a power transformation of 0.182 although the F statistic of 8.33 did not indicate linearity when compared with the critical F of 2.99 at P=.95. Calculations at these second and third levels were not always necessary and even when performed did not always lead to a satisfactory condition of linearity. 

Equilibrium constants for formation of iron(III) complexes of several oxoanions, of phosphorus, arsenic, sulfur, and selenium, have been reported. The kinetics and mechanism of complex formation in the iron(III)-phosphate system in the presence of a large excess of iron(III) involve the formation of a tetranuclear complex, proposed to be [Fc4(P04)(0H)2(H20)i6]. The high stability of iron(III)-phosphate complexes has prompted suggestions that iron-containing mixed hydroxide or hydroxy-carbonate formulations be tested for treatment of hyperphosphatemia. " ... 

The North Central Region, in addition to the Olsen method, uses the Bray and Kurtz P-1 test for phosphorus (Bray and Kurtz, 1945), which has proved to be well correlated with crop response to phosphate fertilizer on acid to neutral soils in the region. Each state experiment station has developed correlations and calibrations for the particular soil conditions within its own state, so field experience over a number of years or decades is necessary when deciding which methods to adopt. When bringing samples from remote sites back to the laboratory, it is therefore important to assess the nature of the soil at that site in order to choose the optimum method. If the same method has... 

Moissan reasoned that if he were trying to liberate chlorine he would not choose a stable solid like sodium chloride, but a volatile compound like hydrochloric acid or phosphorus pentachloride. His preliminary experiments with silicon fluoride convinced him that this was a very stable compound, and that, if he should ever succeed in isolating fluorine, it would unite with silicon with incandescence, and that therefore he might use silicon in testing for the new halogen. After many unsuccessful attempts to electrolyze phosphorus trifluoride and arsenic trifluoride, and after four interruptions caused by serious poisoning, he finally obtained powdered arsenic at the cathode and some gas bubbles at the anode. However, before these fluorine bubbles could reach the surface, they were absorbed by the arsenic trifluoride to form pentafluoride (18, 23). 

Several catalysts and initiator systems have been tested for the polymerization of GlcAnBzl3, including the following Lewis acids boron trifluoride and its etherate, phosphorus pentafluoride, titanium tetrachloride, and antimony pentachloride and pentafluoride. Several cationic initiators have also been used, including (triphenylmethyl) antimony hexachloride, 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl hexa-fluorophosphate, acetyl hexafluorophosphate, pentamethylbenzyl hexa-fluorophosphate (most of which were generated in situ), and triethyl-... 

It is recommended that the compound be fused with a mixture of sodium carbonate (2 parts) and sodium peroxide (1 part) as in the test for Phosphorus. Extract the fused mass with water, filter, and acidify with dilute hydrochloric acid. Pass hydrogen sulphide through the hot solution arsenic is precipitated as yellow arsenic sulphide. If antimony is present, it will be precipitated as orange antimony trisulphide. 

Sodium hypophosphite NaPO H3. the only sodium hypophosphite. is formed 11) by reaclion of yellow phosphorus and sodium hydroxide solution (phosphine simultaneously fomicdl, (2) by reaclion of hypophosphorous acid and sodium hydroxide, and evaporating. Sodium hypophosphite. upon healing, yields sodium phosphate and sndiutn phosphide. Common tests for ihc hypophosphiles are as follows ... 

Test for phosphorus. The presence of phosphorus may be indicated by a smell of phosphine during the sodium fusion and the immediate production of a jet-black colour when a piece of filter paper moistened with silver nitrate solution is placed over the mouth of the ignition tube after the sample has been dropped on the hot sodium. Treat 1.0ml of the fusion solution with 3ml of concentrated nitric acid and boil for 1 minute. Cool and add an equal volume of ammonium molybdate reagent (3). Warm the mixture to 40-50 °C, and allow to stand. If phosphorus is present, a yellow crystalline precipitate of ammonium 12-molybdophosphate, (NH4)3[PMo12C>4o], will separate. 

USDA-CSREES (1998). Soil Testing for Phosphorus Environmental Uses and Implications, Southern Cooperative Series Bulletin 389. SERA-IEG 17, May. 

A solid waste containing yellow and white phosphorus may become characterized as a hazardous waste when subjected to testing for reactivity as stipulated in 40 CFR 261.23 and, if so characterized, must be managed as a hazardous waste (40 CFR 261.23 [7/1/90]). dGroup D = Not classifiable as to carcinogenicity in humans... 

A similar kind of synergy was investigated by Cui et al.,90 who prepared by melt blending nano-modified ATH using oxalic acid, a red phosphorus masterbatch and high impact polystyrene (HIPS). Unfortunately, the use of variable amounts of HIPS in the compositions has limited the possibility to see evidence of synergistic effects. The authors have stressed the well-developed and robust character of the char layer formed after UL-94V flame test for the composition HIPS/modified ATH/ Red phosphorus (68/20/12). The use of FTIR confirmed also that both P-O-P and P-O-C groups were present in the char. 

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