Mechanism of interference by hemoglobin in the determination of total bilirubin. II. Method of Jendrassik-Grof.

1980 ◽  
Vol 26 (1) ◽  
pp. 26-29 ◽  
Author(s):  
B C Shull ◽  
H Lees ◽  
P K Li
Keyword(s):  
Hydrogen Peroxide ◽  
Related Species ◽  
Total Bilirubin ◽  
Probable Mechanism ◽  
Spectral Interference ◽  
Nitrite Ion ◽  
Reaction Conditions ◽  
Hemoglobin Oxidation ◽  
Rapid Formation

Abstract Oxyhemoglobin in erythrocyte hemolysates interferes with the Jendrassik-Grof assay. Destruction of azobilirubin occurs when oxyhemoglobin is oxidized to methemoglobin during diazotization or to alkaline hematin with addition of alkaline tartrate. The most probable mechanism is by oxidation with an agent such as hydrogen peroxide or a related species resulting from hemoglobin oxidation. Methemoglobin also appears to cause some destruction of azobilirubin during diazotization. Methemoglobin forms during diazotization because of reactions of oxyhemoglobin with both diazo reagent and nitrite ion. Formation of methemoglobin is, therefore, more rapid in the test than in the blank mixture and, under reaction conditions, its absorbance is less than that of oxyhemoglobin. This results in spectral interference when neutral azobilirubin is assayed. Alkaline tartrate abolishes this spectral error by causing rapid formation of alkaline hematin in both test and blank.

Mechanism of interference by hemoglobin in the determination of total bilirubin. II. Method of Jendrassik-Grof.

1980 ◽  
Vol 26 (1) ◽  
pp. 26-29 ◽  
Author(s):  
B C Shull ◽  
H Lees ◽  
P K Li
Keyword(s):  
Hydrogen Peroxide ◽  
Related Species ◽  
Total Bilirubin ◽  
Probable Mechanism ◽  
Spectral Interference ◽  
Nitrite Ion ◽  
Reaction Conditions ◽  
Hemoglobin Oxidation ◽  
Rapid Formation

Abstract Oxyhemoglobin in erythrocyte hemolysates interferes with the Jendrassik-Grof assay. Destruction of azobilirubin occurs when oxyhemoglobin is oxidized to methemoglobin during diazotization or to alkaline hematin with addition of alkaline tartrate. The most probable mechanism is by oxidation with an agent such as hydrogen peroxide or a related species resulting from hemoglobin oxidation. Methemoglobin also appears to cause some destruction of azobilirubin during diazotization. Methemoglobin forms during diazotization because of reactions of oxyhemoglobin with both diazo reagent and nitrite ion. Formation of methemoglobin is, therefore, more rapid in the test than in the blank mixture and, under reaction conditions, its absorbance is less than that of oxyhemoglobin. This results in spectral interference when neutral azobilirubin is assayed. Alkaline tartrate abolishes this spectral error by causing rapid formation of alkaline hematin in both test and blank.

Mechanism of interference by hemoglobin in the determination of total bilirubin. I. Method of Malloy-Evelyn.

1980 ◽  
Vol 26 (1) ◽  
pp. 22-25 ◽  
Author(s):  
B C Shull ◽  
H Lees ◽  
P K Li
Keyword(s):  
Ethylene Glycol ◽  
Molecular Mass ◽  
Potassium Iodide ◽  
Total Bilirubin ◽  
Final Concentration ◽  
Probable Mechanism ◽  
Reaction Conditions ◽  
Oxidative Reaction ◽  
Rapid Destruction

Abstract Oxyhemoglobin is the species of hemoglobin in erythrocyte hemolysates that inhibits the diazo reaction. Ferric hemoglobin derivatives and species with relatively low molecular mass do not interfere. Conversion of oxyhemoglobin to acid hematin under assay reaction conditions is associated with rapid destruction of bilirubin, which accounts for the diazo reaction error. The most probable mechanism for this destruction of bilirubin is an oxidative reaction involving H2O2, formed in the oxidation of hemoglobin, and acid hematin acting as a pseudoperoxidase. We could find no evidence for other mechanisms of interference such as spectral error or azobilirubin destruction. Addition of potassium iodide, 4.0 mmol/L final concentration in the reaction mixture, eliminates interference from hemoglobin added to give concentrations as great as 10 g/L. It also eliminated the effects of hemolysis in the method of Ertingshausen et al. (Clin. Chem. 19: 1366, 1973), in which ethylene glycol is used as the accelerator.

Mechanism of interference by hemoglobin in the determination of total bilirubin. I. Method of Malloy-Evelyn.

1980 ◽  
Vol 26 (1) ◽  
pp. 22-25 ◽  
Author(s):  
B C Shull ◽  
H Lees ◽  
P K Li
Keyword(s):  
Ethylene Glycol ◽  
Molecular Mass ◽  
Potassium Iodide ◽  
Total Bilirubin ◽  
Final Concentration ◽  
Probable Mechanism ◽  
Reaction Conditions ◽  
Oxidative Reaction ◽  
Rapid Destruction

Abstract Oxyhemoglobin is the species of hemoglobin in erythrocyte hemolysates that inhibits the diazo reaction. Ferric hemoglobin derivatives and species with relatively low molecular mass do not interfere. Conversion of oxyhemoglobin to acid hematin under assay reaction conditions is associated with rapid destruction of bilirubin, which accounts for the diazo reaction error. The most probable mechanism for this destruction of bilirubin is an oxidative reaction involving H2O2, formed in the oxidation of hemoglobin, and acid hematin acting as a pseudoperoxidase. We could find no evidence for other mechanisms of interference such as spectral error or azobilirubin destruction. Addition of potassium iodide, 4.0 mmol/L final concentration in the reaction mixture, eliminates interference from hemoglobin added to give concentrations as great as 10 g/L. It also eliminated the effects of hemolysis in the method of Ertingshausen et al. (Clin. Chem. 19: 1366, 1973), in which ethylene glycol is used as the accelerator.

scholarly journals Spectrophotometric determination of ascorbic acid by horseradish peroxidase

2020 ◽  
Vol 10 (2) ◽  
pp. 17-22
Author(s):  
Vladan Đurić ◽  
Nebojša Deletić
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Pharmaceutical Products ◽  
Reaction Conditions ◽  
Hydrogen Peroxide Decomposition ◽  
Peroxide Decomposition ◽  
Daily Dose ◽  
Ascorbate Concentration ◽  
Absorbance Changes

L-ascorbic acid is one of the essential nutrients and most common food supplements, fortificants, and preservatives. It is commercially available as solutions, drops, tablets, capsules, crystal powder, beverage mixtures, multivitamin formulations, and multi antioxidant formulations. The usual daily dose is from 25 mg to 1.5 g. Ascorbic acid is a distinctly reducing agent with low redox potential (0.18 and 0.08 V at pH 4.5 and 6.4, respectively). Based on ascorbate property, numerous methods for its quantitative determination are developed, from titrimetric, electrochemical, and chromatographic methods, to fluorometric and kinetic ones. Enzyme peroxidase is interfered with by ascorbic acid, which decreases the oxidation speed of its co-substrates during hydrogen peroxide decomposition by peroxidase. Absorbance changes at the wavelength of corresponding reagents are in correlation with ascorbate concentration. During this study, benzidine and o-tolidine have been used as chromogenic reagents. Reaction conditions were optimized for various buffer systems, calibration curves were constructed, and limits of detection (0.04 mmol/L) and quantification (0.12 mmol/L) were calculated. Using calibration charts, it was possible to detect ascorbic acid within limits from 0.4 to 10 mmol/L. The optimized method was applied for the determination of ascorbic acid in pharmaceutical products. The method was characterized by exceptional sensitivity and accuracy, but only for preparations not containing substances that affect enzyme peroxidase.

Electrocatalytic Activities of Graphene/Nile Blue Nanocomposite Toward Determination of Hydrogen Peroxide and Nitrite Ion

2016 ◽  
Vol 28 (9) ◽  
pp. 1957-1969 ◽  
Author(s):  
Reza Karimi Shervedani ◽  
Elham Ansarifar ◽  
Marzieh Samiei Foroushani
Keyword(s):  
Hydrogen Peroxide ◽  
Nile Blue ◽  
Nitrite Ion

scholarly journals Kinetic spectrophotometric determination of Co(II) ion by the oxidation of ponceau 4R by hydrogen peroxide

2006 ◽  
Vol 71 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Zora Grahovac ◽  
Snezana Mitic ◽  
Emilija Pecev ◽  
Snezana Tosic
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Method ◽  
Calibration Graph ◽  
Borate Buffer ◽  
Linear Calibration ◽  
Reaction Conditions ◽  
Ponceau 4R ◽  
Optimum Reaction ◽  
Kinetic Spectrophotometric

Anew, sensitive and simple kinetic method has been developed for the determination of traces of Co(II) ions based on their catalytic effect in the oxidation of trisodium-2-hydroxy-1-(4-sulphonato-1-naphthylazo)naphthalene-6,8-disulphonate (red artificial color Ponceau 4R) by hydrogen peroxide in borate buffer. The reaction was followed spectrophotometrically by tracing the oxidation product at 478.4 nm within 1 min after the initiation of the reaction. The optimum reaction conditions are: borate buffer (pH 10.50), Ponceau 4R (8 x10-6 mol/dm3), H2O2 (3 x10-2 mol/dm3) at 22 ?C. Following this procedure, Co(II) can be determined with a linear calibration graph up to 1.17 ng/cm3 and a detection limit of 0.20, based on the 3??criterion. The relative error ranges between 4.80-3.25 % for the concentration interval of Co(II) ions 1.76-17.61 ng/cm3. The effects of certain foreign ions on the reaction rate were determined for an assessment of the selectivity of the method. The method was applied for the determination of Co(II) in pharmaceutical samples.

Sensitive and simple detection of trace hydrogen peroxide based on a resonance light scattering assay

2015 ◽  
Vol 7 (20) ◽  
pp. 8750-8756 ◽  
Author(s):  
Ningli Tang ◽  
Yaqi Shan ◽  
Ronghui Zhang ◽  
Xinglong Meng
Keyword(s):  
Hydrogen Peroxide ◽  
Light Scattering ◽  
Resonance Light Scattering ◽  
Influential Factors ◽  
New Method ◽  
Reaction Conditions ◽  
Simple Detection ◽  
Optimum Reaction

A new method for the resonance light scattering determination of hydrogen peroxide has been developed, and the optimum reaction conditions, influential factors and applications were investigated.

Study of the Catalytic Effects of Trace Titanium on Oxidation of Pyronin B with Hydrogen Peroxide and its Application

2012 ◽  
Vol 602-604 ◽  
pp. 1233-1237
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Medium ◽  
Reaction Conditions ◽  
Relative Standard ◽  
Extraction Separation ◽  
Optimum Reaction ◽  
Kinetic Spectrophotometric ◽  
Replicate Measurements ◽  
Catalytic Effects

A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts titanium (IV), based on the catalytic effect of Ti (IV) on the oxidation pyronin B with hydrogen peroxide in 0.02 mol/L sulfuric acid, is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of pyronin B at 555 nm. The detection limit of the method is 0.017 μg/L, and the linear range is 0.055–1.0 µg/L. The influences of reaction medium and acidity, concentrations of reactants, reactive temperature and foreign ions is also discussed. The optimum reaction conditions were established. The relative standard deviation for 11 replicate measurements of 0.010 and 0.020 μg/25mL of titanium (IV) were 2.8 % and 2.3 %, respectively. In combination with solvent extraction separation, the method has been successfully applied to the determination of trace titanium (IV) in rock samples. The results are in good agreement with the certified volumes with the relative standard deviations (RSD) of 1.6 %–3.6 %.

scholarly journals SPECTROPHOTOMETRIC DETERMINATION OF ASCORBIC ACID BY HORSERADISH PEROXIDASE

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Vladan R. Đurić ◽  
Nebojša R. Deletić
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Pharmaceutical Products ◽  
Reaction Conditions ◽  
Hydrogen Peroxide Decomposition ◽  
Peroxide Decomposition ◽  
Daily Dose ◽  
Ascorbate Concentration ◽  
Absorbance Changes

L-ascorbic acid is one of the essential nutrients and most common food supplements, fortificants, and preservatives. It is commercially available as solutions, drops, tablets, capsules, crystal powder, beverage mixtures, multivitamin formulations, and multi antioxidant formulations. The usual daily dose is from 25 mg to 1.5 g. Ascorbic acid is a distinctly reducing agent with low redox potential (0.18 and 0.08 V at pH 4.5 and 6.4, respectively). Based on ascorbate property, numerous methods for its quantitative determination are developed, from titrimetric, electrochemical, and chromatographic methods, to fluorometric and kinetic ones. Enzyme peroxidase is interfered with by ascorbic acid, which decreases the oxidation speed of its co-substrates during hydrogen peroxide decomposition by peroxidase. Absorbance changes at the wavelength of corresponding reagents are in correlation with ascorbate concentration. During this study, benzidine and o-tolidine have been used as chromogenic reagents. Reaction conditions were optimized for various buffer systems, calibration curves were constructed, and limits of detection (0.04 μmol/L) and quantification (0.12 μmol/L) were calculated. Using calibration charts, it was possible to detect ascorbic acid within limits from 0.4 to 10 μmol/L. The optimized method was applied for the determination of ascorbic acid in pharmaceutical products. The method was characterized by exceptional sensitivity and accuracy, but only for preparations not containing substances that affect enzyme peroxidase.

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