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

Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A/hydrogen peroxide method

1998 ◽  
Vol 128 (1-2) ◽  
pp. 43-48 ◽  
Author(s):  
Gordana A. Milovanović ◽  
Radivoj B. Petronijević ◽  
Mira M. Čakar
Keyword(s):  
Hydrogen Peroxide ◽  
Nile Blue ◽  
Kinetic Determination ◽  
Nile Blue A ◽  
Total Selenium ◽  
Peroxide Method

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.

scholarly journals Determination of lisinopril in pharmaceuticals by a kinetic spectrophotometric method

2012 ◽  
Vol 77 (10) ◽  
pp. 1437-1442 ◽  
Author(s):  
Mira Cakar ◽  
Gordana Popovic
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Method ◽  
Nile Blue ◽  
Borate Buffer ◽  
Nile Blue A ◽  
Tangent Method ◽  
Kinetic Spectrophotometric ◽  
Detection And Quantification

A kinetic spectrophotometric method for determination of lisinopril in pharmaceuticals has been developed. The method is based on activator action of lisinopril on Cu(II) ions catalysing the oxidation of nile blue A with hydrogen peroxide in borate buffer (pH 9.3). A decrease of the absorbance was recorded at 635 nm for 5 min at 25?C. The linearity was established applying the tangent method within the concentration range of lisinopril from 0.8-6.4 ?g mL-1, the detection and quantification limits being 0.158 ?g mL-1 and 0.480 ?g mL-1, respectively. The method has been successfully applied in three brands of tablets containing lisinopril alone or in combination with hydrochlorothiazide.

Enzymatic colorimetry of lecithin and sphingomyelin in aqueous solution.

1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Amniotic Fluid ◽  
Enzymatic Reaction ◽  
Detergent Solution ◽  
Enzymatic Determination ◽  
Red Color ◽  
Hydrolysis Of ◽  
Zwitterionic Detergent

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.

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