Modifications of spectrophotometric methods for total phosphorus determination in meat samples

2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Aneta Jastrzębska
Keyword(s):  
Total Phosphorus ◽  
Reducing Agents ◽  
Statistical Parameters ◽  
Molybdenum Blue ◽  
Spectrophotometric Methods ◽  
Hydrazine Sulphate ◽  
Meat Samples ◽  
Blue Reaction ◽  
Better Than

AbstractSpectrophotometric determination of total phosphorus in meat samples was modified using the molybdenum blue reaction with the following reducing agents: ascorbic acid (AA), hydrazine sulphate (HS), and mixture of hydroquinone and hydrazine sulphate (HHS). Proposed methods were validated by evaluation of statistical parameters such as: linearity, sensitivity, limits of detection (DL) and quantification (QL), precision, and accuracy, against the standard and malachite green (MG) modified procedures and by applying food certified materials. The values of within-day and between-days precision in meat samples for all tested reducing agents were better than 3.4 % and 4.2 %, respectively. The recoveries for CRMs analyses were between 92 % and 102.3 %. Obtained results suggest usefulness of the hydroquinone and hydrazine sulphate mixture in the determination of phosphorus ions.

scholarly journals Construction and evaluation of an automated flow injection-stopped flow analyser for multipoint reaction rate spectrophotometric methods. Determination of ammonia nitrogen, creatinine and phosphate

1991 ◽  
Vol 13 (5) ◽  
pp. 199-207 ◽  
Author(s):  
Constantinos A. Georgiou ◽  
Michael A. Koupparis
Keyword(s):  
Flow Injection ◽  
Reaction Rate ◽  
Assembly Language ◽  
Ammonia Nitrogen ◽  
Stopped Flow ◽  
Data Sampling ◽  
Ramp Generator ◽  
Spectrophotometric Methods ◽  
Blue Reaction

The construction and evaluation of a fully automated Flow Injection-Stopped Flow (FI-SF) spectrophotometric analyser is described. A microcomputer (Rockwell AIM 65) is used to control the analyser (sample injection, stop and start of the pump) through a suitable interface. Data acquisition is achieved using a 12 bit ADC card and a suitable subroutine in 6502 assembly language, allowing data sampling at a frequency of 7.5 kHz. The measurement interface and software were evaluated using a voltage ramp generator. A precision of 0.02-1.1% RSD (N =10) was obtained for voltage ramps in the range of 1-37 mVs-1. The FI-SF analyser was evaluated in routine analysis by developing FI-SF kinetic spectrophotometric methods for the determination of ammonia nitrogen (20-250 ppm, 0.4-2.5% RSD) based on the Berthelot reaction, creatinine (20-220 ppm, 0.9-3.6% RSD) based on the Jaffé reaction, and phosphate (5-30 ppm, 1.0-3.3% RSD) based on the phosphomolybdenum blue reaction. The reaction rate is measured by linear fitting of multiple absorbance readings vs time. Algorithms for automated estimation of the residence time, the linear range of the reaction curve, and data treatment are presented.

scholarly journals Determination of Total Phosphorus in Foods by Colorimetry: Summary of NMKL Collaborative Study

1996 ◽  
Vol 79 (6) ◽  
pp. 1408-1410 ◽  
Author(s):  
T Katrhna Pulliainen ◽  
Harriet C Wallin
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Content ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Milk Powder ◽  
Molybdenum Blue ◽  
Relative Standard ◽  
Standard Deviations ◽  
Skimmed Milk Powder

Abstract A collaborative study was conducted to validate a spectrophotometric–colorimetric method for determining total phosphorus in foods. The sample was dry-ashed in the presence of zinc oxide, and total phosphorus content was measured colorimetrically as molybdenum blue. Twelve laboratories from the Nordic countries participated in the study. The test materials included potato flour, sausage, cold ham, infant formula powder, cheese, and skimmed milk powder. Participants received 12 randomly coded samples of 2 blind duplicates of each material. Phosphorus contents of materials varied between 0.076 and 0.96 g/100 g. Relative standard deviations for repeatability of the method varied from 1.1% for 0.96 g phosphorus/100 g to 5.4% for 0.29 g phosphorus/100 g. Relative standard deviations for reproducibility varied from 3.6% for 0.96 g phosphorus/100 g to 7.7% for 0.23 g phosphorus/100 g. The colorimetric method for determination of total phosphorus in foods has been adopted first action by AOAC INTERNATIONAL as an NMKUAOAC INTERNATIONAL method.

THE DETERMINATION OF NUCLEOTIDE PHOSPHORUS WITH A STANNOUS CHLORIDE - HYDRAZINE SULPHATE REAGENT

1964 ◽  
Vol 42 (2) ◽  
pp. 287-292 ◽  
Author(s):  
R. O. Hurst
Keyword(s):  
Light Absorption ◽  
Stannous Chloride ◽  
Reducing Agent ◽  
Accurate Estimation ◽  
Molybdenum Blue ◽  
Colorimetric Measurement ◽  
Highly Sensitive ◽  
Hydrazine Sulphate

Stabilization of stannous chloride as reducing agent for the analysis of phosphorus by the molybdenum blue method has been achieved by combining it with hydrazine sulphate. Application of the procedure to the determination of inorganic and nucleotide phosphorus is described. Colorimetric measurement of light absorption is made at 700 mμ, permitting a highly sensitive and accurate estimation of phosphorus.

Comparison of the reactions of ferric ions with Chromazurol S, Eriochromazurol B and Eriochromcyanine R in the presence of surface active substances and spectrophotometric determination of Fe(III)-ions with Chromazurol S-cetylpyridinium bromide system

1980 ◽  
Vol 45 (10) ◽  
pp. 2656-2669 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Dagmar Gotzmannová
Keyword(s):  
Ferric Ions ◽  
Cetylpyridinium Bromide ◽  
Absorption Coefficients ◽  
Statistical Parameters ◽  
Spectrophotometric Methods ◽  
Chromazurol S ◽  
Surface Active ◽  
Active Substances ◽  
Serum Components

The spectrophotometric methods of determining Fe(III) ions with Chromazurol S, Eriochromazurol B and Eriochromcyanine R in the presence of cationic, anionic and nonionic tensides were compared using the basic optical and statistical parameters. A method was proposed and developed for the determination of Fe(III) ions using Chromazurol S in blood serum and plasma at pH 4.7-5.0 in a medium of 2 . 10-4M cetylpyridinium bromide and 0.1M pyridine buffer and at pH 6.0-6.5 in a medium of 2 . 10-3M cetylpyridinium bromide and 0.1M hexamethylenetetramine buffer with molar absorption coefficients of 1.31 . 105 and 1.40 . 105, respectively. The determination is sufficiently specific even at pathological concentrations of the other serum components.

Measurement of Residues of Cygon Insecticide and Its Oxygen Analog by Total Phosphorus Determination after Isolation by Thin-Layer Chromatography

1964 ◽  
Vol 47 (4) ◽  
pp. 645-651
Author(s):  
W A Steller ◽  
A X Curry
Keyword(s):  
Thin Layer ◽  
Total Phosphorus ◽  
Phosphorus Content ◽  
Molybdenum Blue ◽  
Oxygen Analog ◽  
Chromatographic Plate ◽  
Layer Chromatography ◽  
Chromatographic Isolation ◽  
Phosphorus Determination

Abstract A total phosphorus method incorporating thin-layer chromatographic isolation is described for the determination of Cygon Insecticide (generic name, dimethoate) and its oxygen analog. Residues of the insecticides are extracted from macerated plant tissue, and the extract, after solvent partitioning and concentration, is spotted on a thin-layer chromatographic plate. After development of the plate, the areas corresponding to the two compounds are scraped and eluted. The phosphorus content of the respective eluates is determined by an improved molybdenum blue method, and concentrations of dimethoate and its oxygen analog in the original samples are calculated.

Determination of Total Phosphorus in Foods by Colorimetric Measurement of Phosphorus as Molybdenum Blue after Dry-Ashing: NMKL1 Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1557-1561 ◽  
Author(s):  
T Katrdna Pulliainen ◽  
Harriet C Wallin
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Total Phosphorus ◽  
Phosphorus Content ◽  
Milk Powder ◽  
Molybdenum Blue ◽  
Colorimetric Measurement ◽  
Relative Standard ◽  
Dry Ashing

Abstract A spectrophotometric method in which the sample is dry-ashed in the presence of zinc oxide, and total phosphorus content is measured colorimetrically as molybdenum blue was evaluated by 12 participating laboratories from the Nordic countries. The study included potato flour, sausage, cold ham, infant formula powder, cheese, and skimmed milk powder. The materials were presented to the participants as 12 randomly coded samples of 2 blind duplicates of each material. The phosphorus content of the materials varied between 0.076 and 0.96 g/100 g. The relative standard deviation for repeatability of the method varied from 1.1% for 0.96 g phosphorus/100 g to 5.4% for 0.29 g phosphorus/100 g. The relative standard deviation for reproducibility varied from 3.6% for 0.96 g phosphorus/100 g to 7.7% for 0.23 g phosphorus/100 g.

Microanalytical determination of calcium, phosphate, and arsenate including kinetics of formation of molybdenum blue from reduction of molybdoarsenic acid by ferrous ammonium sulphate

1987 ◽  
Vol 65 (6) ◽  
pp. 1313-1315 ◽  
Author(s):  
U. S. Rat ◽  
T. S. B. Narasaraju
Keyword(s):  
Calcium Phosphate ◽  
Ammonium Sulphate ◽  
Ferrous Ammonium Sulphate ◽  
Molybdenum Blue ◽  
Spectrophotometric Methods ◽  
Rate Determining Step ◽  
Kinetics Of Formation ◽  
Ferrous Ammonium ◽  
Kinetics Of

A method for the microdetermination of calcium, phosphate, and arsenate in mixtures of the three has been developed. In an aliquot of the mixture calcium was determined complexometrically using EDTA. Phosphate and arsenate were determined in second and third aliquots, respectively, using spectrophotometric methods. The interference of arsenate in the determination of phosphate was avoided by masking arsenate with thiosulphate. The kinetics of formation of molybdenum blue from molybdoarsenic acid by reduction with ferrous ammonium sulphate was also studied. The rate-determining step was found to be the reduction of molybdoarsenic acid with iron(II); the reaction was first order in iron(II) and arsenate over the concentration ranges studied. Values found for the enthalpy, entropy, and free energy of activation were 22, 0.05, and 7.5 kcal, respectively.

Sign in / Sign up

Export Citation Format

Share Document