Phosphorus availability index

Selby, T. W., Phosphorus Volatility of Lubricants — Use of the Phosphorus Emission Index of Engine Oils, 9th F L Asia Conference, Singapore, January 21—24, 2003. (available on CD from F L Asia, Inc., Manila, Philippines). 

KAWADA H., NISHADA T. and YOSHIOKA J. 1973. Chemical composition of soil and foliage in relation to the growth of Hinoki (Chamaecyparis obtusa S. et Z). Appraisal of carbon/organic phosphorus ratio of forest soil as an index of phosphorus availability. Bulletin of the Government Forest Experiment Station (Japan), No. 253, pp.1-37. 

This review is intended to cover most of the aspects of NMR in phosphorus chemistry, especially stressing those aspects directly related to electronic and structural factors. Some subjects will only be briefly reviewed, e.g. resonances in solid compounds, in metal complexes [this subject has been treated in a previous article in this seriesa969,1)] and biological applications. All the compounds reviewed are tabulated in either Formula Index I (inorganics) or Formula Index II (organics), the whole comprising of more than four thousand five hundred entries. These indicesf list all available chemical shifts for phosphorus and fluorine those for other nuclei (except protons) are reported in the text of this review. 

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... 

The components in a mixture separate in the column and exit from the column at different times (retention times). As they exit, the detector registers the event and causes the event to be recorded as a peak on the chromatogram. A wide range of detector types are available and include ultraviolet adsorption, refractive index, thermal conductivity, flame ionization, fluorescence, electrochemical, electron capture, thermal energy analyzer, nitrogen-phosphorus. Other less common detectors include infrared, mass spectrometry, nuclear magnetic resonance, atomic absorption, plasma emission. 

Available nutrients. This is the level of phosphate, potash and magnesium and it is indicated by index ratings 0-9. A deficiency level is indicated by 0 and an excessively high level by 9 (never reached imder field conditions). An index of 2 and 3 is satisfactory for farm crops. As indices drop below 2 more fertiliser is recormnended so that the index will go up over a period of time, and as they get above 2 or 3 the recommendations decrease until, at index 4 and over, no applications of phosphorus, potassiirm or magnesium are required. 

The hexokinase for use in ATP determination by this method can be obtained from baker s yeast using the isolation procedure of Berger et al. (1) or of Meyerhof (14). Crystalline hexokinase is unnecessary but the preparation should be free of ATPase and other phosphatase activity. (Partially purified hexokinase is now available commercially from Pabst Laboratories.) An aliquot of the extract to be tested is assayed for total 7-minute hydrolyzable phosphate (8). Another aliquot is incubated with hexokinase plus glucose, and the 7-minute hydrolyzable phosphate is again determined. Inasmuch as the glucose-6-phosphate produced by the action of hexokinase on ATP and glucose is not acid labile, the decrease in acid-labile phosphorus is an index of the amount of ATP present. 

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