Phosphorus standard solution

M. Phosphorus standard solution 1 ml = 2.5 pg phosphorus, prepared by dissolution of 0.2197 g KH2P0 (dried over H2S0 ) with 25 ml sulphuric acid (1+1), and filled up to 1 1. An aliquot of this solution is diluted 20 times. 

Aliquot parts of the phosphorus standard solution (M) containing 2.5 to 50 Mg phosphorus are put in several 100 ml beakers. 2 g boric acid (F) are added. One adjusts to pH 2 and proceeds as described above. A solution without phosphorus addition is used as blank. The accuracy is 10 % at concentration levels of the order of 10 Mg/g. The duration of the analysis is approximately 9 hours. 

Quantitation of tebuconazole residue in water extracts is also performed by the calibration technique. Construct a new calibration curve of 0.5-, 1-, 2-, and 5-mg L equivalent tebuconazole standard solutions for each set of analyses. Inject 5- o.L aliquots of the standard solutions. The injection volume should be kept constant as the peak area varies with the injection volume by nitrogen-phosphorus detection. Plot the peak area against the injected concentrations of tebuconazole. 

Figure 5.15. Gas chromatograms of liquid precursors for producing n-type Si films, namely, solution of CPS with white phosphorus dissolved at 1 wt% initial (nonirradiated) solution 20-min-, 25-min-, and 30-min-irradiated solutions and white phosphorus alone solution, for comparison, all of which were diluted with toluene before analysis. Trans-decalin was used as a standard for a quantitative estimation of an unreacted CPS monomer. [Reproduced with permission from Ref. 25. Copyright 2007 The Japan Society of Applied Physics.]...

Phosphorus intermediate standard solution, 20 pg mh - pipette 10 ml of the phosphorus stock standard solution, 1 mg mh into a 500-ml volumetric flask, make up to the mark and mix. Add 1 drop of toluene to the solution. 

Phosphorus working standard solutions, 0-7 pg P mh - prepare fresh daily solutions by pipetting 0, 5, 10, 15, 20, 25, 30 and 35 ml of the phosphorus intermediate standard solution, 20 pg mh into 100-ml volumetric flasks, make up to the mark with sodium bicarbonate reagent, and mix. These will contain 0, 1,2, 3, 4, 5, 6 and 7 pg P mh respectively. 

Procedure. Carry out the extraction and then determine phosphorus as in Method 5.9a, except that working standard solutions should be made up in the Mehlich 1 extractant. Determine potassium and magnesium as in Method 5.10, except that standards are made up in Mehlich 1 extractant. Determine calcium as in Method 5.2, except that standards are made up in Mehlich 1 extractant. The composition of composts is so variable that appropriate dilutions of extracts may be required, and calculations adjusted accordingly. 

Phosphorus intermediate standard solution, 200 pg P2O5 mh (87.3 pg P mh ) - dilute 20 ml of the phosphorus stock standard solution to 100 ml with water. 

Procedure (standard curve). Fill a 50-ml burette with the phosphorus intermediate standard solution and dispense 25, 26, 27, 28, 29, 30 and 31 ml into a series of 100-ml volumetric flasks. These will contain 50, 52, 54, 56,... 

Elemental composition P 37.78%, H 3.69%, 0 58.54%. The acid in solid form may be identified by its physical properties. Aqueous solution may be heated and phosphorus acid is converted to phosphoric acid which is measured for orthophosphate ion by ion chromatography or colorimetry (see Phosphoric Acid). A cold aqueous solution may be analyzed for phosphite ion by ion chromatography, following appropriate dilution. Strength of the acid in an aqueous solution may be measured by acid-base titration using a standard solution of alkali. Also, titration against a standard solution of silver nitrate using potassium chromate as indicator may serve as an additional confirmatory test. 

Boron compounds can be added in combination with other chemicals such as nitrogen and phosphorus. A solution containing sodium tripolyphosphate, boric acid, and ammonia provides a ready-to-use treatment on cellulose products such as plywood, fiberboard, and cardboard (87). The resulting products passed the British Standard 476, Section 6 (Fire Propagation test) Class 0 and Class I requirements of the British Standard Section 7 (Surface Spread of Flame). 

Standard phosphorus(V) solution 1 mg/ml. Dissolve in water 4.3900 g of potassium dihydrogen phosphate (KH2PO4) dried at 110°C, add 1 ml of CHCI3 (to prevent the formation of mould), and dilute with water to 1 litre. 

All fractions are made up to measured volumes and aliquots are removed for analysis. RNA may be measured by the orcinol reaction and DNA by the di-phenylamine reaction, the values obtained being referred to those obtained upon standard solutions of pure RNA and DNA, respectively. (In the S method, these are determined in the one and only nucleic acid fraction.) In addition, total and inorganic phosphorus in each fraction may be measured. The assay procedures are described in detail in Section III. 

Sodium trimethylphosphate solutions (phosphorus standards) of 5.00-20.00 mg/L are required to be prepared daily for the calibration curve. 

Standard solution (containing tin or titanium for barium and calcium, zirconium for phosphorus, and nickel for zinc) is poured into an X-ray cell. Total net counts (peak intensity— background) for each element and its respective internal standard are collected at their appropriate wavelengths. The ratios between elemental and internal standard counts are calculated and converted into barium, calcium, phosphorus, or zinc concentrations, or a combination thereof, from calibration curves. 

The chromium in the substance is converted into chromate or dichromate by any of the usual methods. A platinum indicator electrode and a saturated calomel electrode are used. Place a known volume of the dichromate solution in the titration beaker, add 10 mL of 10 per cent sulphuric acid or hydrochloric acid per 100 mL of the final volume of the solution and also 2.5 mL of 10 per cent phosphorus) V) acid. Insert the electrodes, stir, and after adding 1 mL of a standard ammonium iron)II) sulphate solution, the e.m.f. is measured. Continue to add the iron solution, reading the e.m.f. after each addition, then plot the titration curve and determine the end point. 

Prepare a series of standards from potassium dihydrogenphosphate covering the range 0-2 mg phosphorus per 100 mL and containing the same concentration of acid, ammonium vanadate, and ammonium molybdate as the previous solution. Construct a calibration curve and use it to calculate the concentration of phosphorus in the sample. 

Reagents. Standard phosphate solution. Dissolve 1.721 g potassium dihydrogen-phosphate (dried at 110 °C) in 1 L of water in a graduated flask. Pipette 10.0 mL of this solution into a 1 L graduated flask and dilute to the mark. The resulting dilute solution contains 0.01 mg phosphorus pentoxide per mL. 

Finally, we tried to activate dopant atoms using pulsed laser irradiation, which is effective in lowering the process temperature. The light source was a 308-nm XeCl excimer laser, which is a standard source for crystallizing a-Si films used in the LTPS process.19 A test sample of 76 nm thickness, prepared from the copolymerized solution (l-wt% phosphorus, 30-min UV irradiation, 500 °C 2hr annealing), was irradiated using a XeCl laser at various intensities to activate the dopant atoms. Figure 5.19 shows the relationship between the... 

When magnesium sulphate was omitted from distilled water samples of phosphorus compounds, recovery was variable. Table 12.11 shows yields of a series of standards with and without the magnesium sulphate addition and with and without the final hydrolysis. The magnesium sulphate is used as an acidic solution (after addition to the seawater sample, the pH was about 3) to minimize silicate leaching from the glassware during evaporation. The acid and heating are necessary to hydrolyse any condensed phosphates in the final mixture. 

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