Phosphates determination

Test method using lA with MG and spectrophotometric procedure were developed for the phosphate determination. Test method allows determination of P(V) in the 10-100 p.g/1 concentration range. Spectrophotometric procedure able to determining lower than 3 p.g/1 P(V) was used for determination it in waters. 

Schwarz, V., The value of galactose phosphate determinations in the treatment of galactosaemia. Arch. Disease Childhood 35, 428-432 (1960). 

In a further method [67] for the determination of ammonium lactate extractable (i.e. available) phosphorus in soils, the sample 5g is extracted with 100ml acidic ammonium lactate and then phosphate determined by flow-injection analysis using the stannous chloride method [68]. 

Solyom has conducted an intercalibration of methods used for the determination of phosphorus in sludges [37]. The methods used to determine phosphorus were that of Koroleff [83] in which the sample is digested with potassium peroxydisulphate and phosphate determined spectro-photometrically. Alternatively a reducing Kjeldahl digestion was used followed by determination of phosphate using molybdate and ascorbic acid. The former method gives somewhat low results. The reducing Kjeldahl method is therefore recommended. 

L-Glutamate synthetase 6.3.1.2 L-Glutamate/ATP Phosphate Determination of phosphate... 

We studied the feasibility of phosphate determination in a low water-soluble API hydrochloride salt. The aim of the work was quantification of phosphate below 0.1% and evaluation of the effect of the high chloride counterion on the determination of phosphate. 

Use the dry residue for digestion and phosphate determination as described in Protocol 1.3.2. 

For quantitative determination the corresponding spots and a blank area of same size are cut out. The cellulose is burned with concentrated nitric acid and the residue is used for phosphate determination according to Protocol 1.3.2, enzymatically by coupled optical test and in the case of P-labeling by counting radioactivity. 

Blood Ca " and phosphate determinations must be made every week until stable, or more frequently if necessary... 

Acetate buffer, pH 5 phenyl phosphate substrate liberated phosphate determined after 30 min at 37°. The figures represent the average percentage of activation (+) or inhibition (—) effected in several experiments. c D-(+)-Tartrate. 

Fluorescence of the CF-containing vesicles was measured with an Amino-Bowan spectrofluorometer (excitation 490, emission 550) using a Coming cut-off filter ( 3-68, 520 nm). Complete release was obtained by adding Triton X-100 ( 0.05% v/v). Light scattering was measured with the same instrument with excitation and emission both set to 400 nm. PS concentrations were assayed by phosphate determination (46). 

Oxidative digestion is performed to determine the organic phosphorus (which is the phosphorus measured after oxidative digestion minus phosphate determined after mild acid hydrolysis). It converts organically bound phosphoms into orthophosphate as shown in the example below ... 

The polysaccharide from Hansenula polymorpha 52-251 has a block type of structure of the main chain, with (1— -2)- and (1— 6)-linked a-D-mannopyranosyl units. The side chains also contain (l- 2) links interspersed with (1— 6) links. Immunochemical experiments revealed the presence of a-D-glucopyranosyl phosphate determinants,118 in common with the polysaccharide of Hansenula wingei, a yeast of interest because of its sexual, agglutination factors.104... 

Phosphate Determine the residual phosphate (calculated as P) in starch phosphate, distarch phosphate, and phosphated distarch phosphate as directed under Phosphorus, Appendix IIIB. 

Consider the following set of data for inorganic phosphate determinations on unhydrolyzed and 7-min hydrolyzed aliquots taken from a 700-ml volume of the MgNH4P04 supernatant obtained in this experiment. 

The method of Lindermann for phosphate determination was modified by using Na ascorbate and stannous chloride as reductants. A blue color develops within 45 min and... 

Recently, Hudson et al. (2000) reported the smallest phosphate concentrations to date for any aquatic system (27 pM) in a study using a new, steady-state bioassay technique for estimating orthophosphate concentrations. In phosphate-limited aquatic systems, accurate determination of orthophosphate is critical because it is the only form of phosphorus that can be directly assimilated by primary producers (e.g., Cembella et al., 1984a,b). The standard phosphomolybdate blue method for phosphate determination falls short of this goal, and is widely thought to overestimate... 

Early colorimetric methods for arsenic analysis used the reaction of arsine gas with either mercuric bromide captured on filter paper to produce a yellow-brown stain (Gutzeit method) or with silver diethyl dithiocarbamate (SDDC) to produce a red dye. The SDDC method is still widely used in developing countries. The molybdate blue spectrophotometric method that is widely used for phosphate determination can be used for As(V), but the correction for P interference is difficult. Methods based on atomic absorption spectrometry (AAS) linked to hydride generation (HG) or a graphite furnace (GF) have become widely used. Other sensitive and specihc arsenic detectors (e.g., AFS, ICP-MS, and ICP-AES) are becoming increasingly available. HG-AES, in particular, is now widely used for routine arsenic determinations because of its sensitivity, reliability, and relatively low capital cost. 

Also, 5 -AMP has been incubated with MgS04 [14], the reaction terminated by trichloroacetic acid precipitation and inorganic phosphate determined in the supernatant by the method of Fiske and SubbaRow [163], Tartrate has been included in the assay medium in order to inhibit acid phosphatase [183]. Inorganic phosphate has been assayed by the method of King [184]. 

A plant was grown in an atmosphere containing C Os (3 x 10 CPM//i,mole). After several weeks a leaf extract was prepared for glucose-l-phosphate determination via reverse isotope dilution analysis. To 20 ml of the extract, 1.5 mmoles of unlabeled dipotassium glucose-1-phosphate were added. A small amount of dipotassium glucose-1-phosphate was reisolated from the extract and recrystallized to constant specific activity from aqueous ethanol. The recrystallized salt had a specific activity of 2.6 X 10 CPM//jLmole. Calculate the concentration of labeled glucose-1-phosphate in the extract. 

Trace phosphate determination is effected by extraction with an organic solution of a quaternary ammonium salt, silylation of the extracted phosphate directly in the organic layer and gas-chromatographic measurement with FID or FPD ... 

---