Microdetermination Of Phosphorus Research Articles

Microdetermination of phosphorus in organic materials from polymer industry by microwave-induced plasma atomic emission spectrometry after microwave digestion

Microwave digestion with nitric acid precedes the determination of phosphorus in different materials from the polymer industry by microwave-induced plasma atomic emission spectrometry (MIP-AES). Atomic emission is measured at the P I 213.618-nm line. The experimental detection limit (DL) is 150 ng ml −1. The accuracy of the method was evaluated with the analysis of certified reference material NIST SRM 1568A Rice Flour. For comparison, the spectrophotometric determination of phosphorus by the phosphomolybdenum blue method was performed.

Simultaneous microdetermination of chlorine, bromine and phosphorus in organic compounds by ion chromatography

A procedure for the simultaneous microdetermination of chlorine, bromine and phosphorus in organic compounds is described. It consists of ion chromatographic analysis, after suitable dilution, of the solution resulting from the collection in water containing hydrogen peroxide of the combustion products obtained by decomposition of the sample in a Schöniger flask. Before analysis, this solution undergoes a post-combustion procedure involving further hydrolysis of the combustion products which allows a nearly quantitative recovery of phosphorus to be achieved even in the presence of other heteroatoms such as chlorine and bromine. This post-combustion step avoids negative errors in the microdetermination of phosphorus by ion chromatography owing to the minor but not insignificant amounts of both pyrophosphate and a cyclic metaphosphate which are formed together with the predominant orthophosphate in the conventional Schöniger combustion of organophosphorus compounds. The accuracy and precision of the overall procedure were evaluated.

Spectrophotometric determination of phosphorus and arsenic in pharmaceutical organic compounds

A simple and accurate method is described for the microdeter-mination of phosphorus and arsenic in some pharmaceutical organic compounds. It is based on the conversion of phosphorus and arsenic into phosphate and arsenate ions respectively, followed by precipitation with quinoline and sodium molybdate reagents. The excess quinoline in the supernatant is spectrophotometrically measured at 312.5 nm in an ammonium acetate background of pH 5.5. The results obtained with 24 structurally different phosphorus and arsenic compounds show an average recovery of 99% and a mean standard deviation of ±1%. Excipients and diluents normally used in drug formulations do not interfere.

Microdetermination of phosphorus in organic substances by precipitation as silver phosphate and indirect titration with EDTA

A rapid titrimetric method for the determination of phosphorus in organic compounds and their metal complexes is described. It is based on the precipitation of silver phosphate, after the decomposition of samples by the oxygen-flask combustion. The precipitate is dissolved with tetracyanonickelate solution and displaced Ni 2+ is titrated with EDTA using murexide as indicator. Satisfactory results were obtained with samples of 2–6 mg containing 4–19% P. The method proved accurate and reliable. It is also relatively simple and fast.

Microdetermination of phosphorus in organic compounds by indirect spectrophotometric reactions

Organo phosphorus compounds are decomposed by closed-flask combustion. The phosphate ions produced are then converted to phosphomolybdic acid and extracted withiso- butyl acetate. The 12molybdate ions associated with each original phosphate ion are spectrophotometrically determined by reactions with alkaline hydrogen peroxide, hydrogen peroxide and benzidine and gallic acid. The colours are measured at 450, 400 and 400nm respectively.

Microdetermination of phosphorus in organic compounds by an amplification reaction

Microdetermination of phosphorus in organic compounds by an amplification reaction

Evaluation of Acid Resistance of Enamel Using Microdetermination of Phosphorus

This investigation was undertaken to evaluate acid resistance of the surface enamel in vivo by the agar plate method reported by TAKEUCHI and KAWASAKI in 1963.The agar plate used in this study were made of agar 0.5% weight/volume) and 0.1M lactic acid-sodium lactate buffer solution, pH 4.5, mixed together by heating in a water bath for 20 minutes and left standing for 24 hours to solidity in a glass vessel of 2mm in depth. Circular plates of 6.5mm in diameter were cut out for experimental use. The surface of the upper central incisor was polished with a slurry of pumice and glycerin and then washed with re-distilled water and dried with compressed air. The plate was placed on the tooth surface for various periods of time to determine the effective time for application in vivo. After application, the phosphorus dissolved from the enamel was estimated by spectrophotometric determination with molybdate-safranin.The subjects were 366 children chosen at random from 1, 036 pupils of the 4th grade (9-10 years old) of elementary school. Fortyseven children were subjected to the application of an agar plate for 5 minutes and 317 of children for 3 minutes.In the case of 5-minute application, the mean value of phosphorus dissolved from the enamel was 1.87μg and the standard deviation was 0.39μg. For the 3-minute application, the values of mean and standard deviation were 1.60μg and 0.38μg, respectively.The data revealed that the distribution of phosphorus dissolved from the enamel showed a fairly normal pattern. With these experiments, the possibility of evaluation of acid resistance of enamel in vivo system by means of the agar plate method devised in this laboratory was demonstrated.Moreover, six female subiects aged 18-20 were studied to determine an appropriate time for in vivo application. The experimental times were set from one to five minutes for each analysis. The results showed that phosphorus dissolved from the enamel in these samples increased with increasing the time of application, notwithstanding the magnitude of acid resistance of individual enamel.From the data in this study, the 3-minute application of the agar plate in vivo seemed to be the best, since it obtains enough phosphorus for analysis with a minimum of trouble to the patient and takes into account possible error in measuring the time.

Evaluation of Acid Resistance of Enamel Using Microdetermination of Phosphorus

Evaluation of Acid Resistance of Enamel Using Microdetermination of Phosphorus

Microdetermination of phosphorus in proteins

Microdetermination of phosphorus in proteins

Photometric microdetermination of phosphorus in motor gasoline by selective extraction of molybdophosphoric acid

Photometric microdetermination of phosphorus in motor gasoline by selective extraction of molybdophosphoric acid

Microdetermination of phosphorus in organic compounds by perchloric acid digestion

Microdetermination of phosphorus in organic compounds by perchloric acid digestion

Quantitative thin layer chromatography of cerebrospinal fluid phospholipids

Quantitative analysis of the phospholipid content of pooled CSF and specimens of CSF from some neurological disorders has been investigated by thin layer chromatography. Sensitivity of the Fiske and Subbarow method for the micro determination of phosphorus has been examined and optimum conditions for maximum development of molybdenum blue found to be within closer limits of time and normality than previously reported. Three different methods of extraction of the phospholipids have been investigated. Well-defined chromatograms were obtained from residues of each extraction demonstrating the presence of lysolecithin, lecithin, sphingomyelin and phosphatidylethanolamine, the yields of these substances from each method are compared and a critical analysis of the discrepancies given. Other lysophospholipids and phosphatidylserine were not found. Results obtained in the present work are compared with those from earlier investigations and with the phospholipid content of serum and brain tissue.

Formation of heteropoly blue by some reduction procedures used in the micro-determination of phosphorus

Formation of heteropoly blue by some reduction procedures used in the micro-determination of phosphorus

Critical investigation of the turbidimetric microdetermination of phosphorus as strychinine phosphomolybdate: A.J. Hegedüs and M. Dvorszky, Mikrochim. Acta, 1959, 141-59

Critical investigation of the turbidimetric microdetermination of phosphorus as strychinine phosphomolybdate: A.J. Hegedüs and M. Dvorszky, Mikrochim. Acta, 1959, 141-59

Micro-determination of phosphorus.

THE increasing application of chromatography to the separation of phospholipids1 has emphasized the need for greater sensitivity in the estimation of total phosphorus.

The micro-determination of phosphorus in organic compounds

The micro-determination of phosphorus in organic compounds

The micro-determination of phosphorus as phosphomolybdate

Research Article| January 01 1933 The micro-determination of phosphorus as phosphomolybdate Robert Henry Aders Plimmer Robert Henry Aders Plimmer 1The Chemistry Department, St Thomas's Hospital Medical School, London Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1933) 27 (6): 1810–1813. https://doi.org/10.1042/bj0271810 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation Robert Henry Aders Plimmer; The micro-determination of phosphorus as phosphomolybdate. Biochem J 1 January 1933; 27 (6): 1810–1813. doi: https://doi.org/10.1042/bj0271810 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1933 CAMBRIDGE UNIVERSITY PRESS1933 Article PDF first page preview Close Modal You do not currently have access to this content.