scholarly journals Determination of Polyhexamethylene Biguanide Utilizing a Glucose Oxidase Enzymatic Reaction

2019 ◽  
Vol 35 (9) ◽  
pp. 1021-1025 ◽  
Author(s):  
Kohei UEMATSU ◽  
Akihito SHINOZAKI ◽  
Hajime KATANO
Keyword(s):  
Glucose Oxidase ◽  
Enzymatic Reaction ◽  
Polyhexamethylene Biguanide

scholarly journals Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

2003 ◽  
Vol 25 (5) ◽  
pp. 109-114 ◽  
Author(s):  
Cherrine K. Pires ◽  
Patrícia B. Martelli ◽  
Boaventura F. Reis ◽  
José L. F. C. Lima ◽  
Maria Lúcia M. F. S. Saraiva
Keyword(s):  
Blood Serum ◽  
Glucose Oxidase ◽  
Confidence Level ◽  
Sampling Rate ◽  
Enzymatic Reaction ◽  
Porous Silica ◽  
Previous Treatment ◽  
Chemiluminescence Detection ◽  
Animal Blood

An automatic flow procedure based on multicommutation dedicated for the determination of glucose in animal blood serum using glucose oxidase with chemiluminescence detection is described. The flow manifold consisted of a set of three-way solenoid valves assembled to implement multicommutation. A microcomputer furnished with an electronic interface and software written in Quick BASIC 4.5 controlled the manifold and performed data acquisition. Glucose oxidase was immobilized on porous silica beads (glass aminopropyl) and packed in a minicolumn (15 } 5 mm). The procedure was based on the enzymatic degradation of glucose, producing hydrogen peroxide, which oxidized luminol in the presence of hexacyanoferrate(III), causing the chemiluminescence. The system was tested by analysing a set of serum animal samples without previous treatment. Results were in agreement with those obtained with the conventional method (LABTEST Kit) at the 95% confidence level. The detection limit and variation coefficient were estimated as 12.0 mg l−1(99.7% confidence level) and 3.5% (n=20), respectively. The sampling rate was about 60 determinations h−1with sample concentrations ranging from 50 to 600 mg l−1glucose. The consumptions of serum sample, hexacyanoferrate(III) and luminol were 46 μl, 10.0 mg and 0.2 mg/determination, respectively.

The Coulometric Determination of Glucose in Human Serum

1968 ◽  
Vol 14 (5) ◽  
pp. 463-476 ◽  
Author(s):  
Robert K Simon ◽  
Gary D Christian ◽  
William C Purdy
Keyword(s):  
Human Serum ◽  
Glucose Oxidase ◽  
Coulometric Titration ◽  
Aerobic Oxidation ◽  
Enzymatic Reaction ◽  
Complete Recovery ◽  
Serum Levels ◽  
Normal Serum ◽  
Coulometric Determination

Abstract The coulometric titration method is combined with the use of an enzymatic analytic reagent for the determination of glucose in human serum. The glucose in 25 µl. of serum is determined in a protein-free filtrate (PFF) with an accuracy of ± 3% and a coefficient of variation of approximately 2%. The procedure routinely covers a concentration range of 25-250 mg/100 ml. Calibrations are linear to at least 450 mg./100 ml. with zero intercept. Glucose oxidase specifically catalyzes the aerobic oxidation of glucose to hydrogen peroxide. The peroxide reacts with iodide, in the presence of molybdenum (VI) catalyst, to form iodine. A known excess of thiosulfate reduces the iodine as it is produced. The reagents and the sample are incubated at 25.0° and pH 5.1. After 15 min., the pH is adjusted to 8.0 with phosphate reagent to stop the enzymatic reaction. The residual thiosulfate is titrated coulometrically with iodine at pH 8.0 to a dead-stop end point at a generating current of 0.4825 ma. The difference between the sample and thiosulfate reagent titers is proportional to the glucose concentration. The method is empirical. Peroxide-reducing impurities in the glucose oxidase preparation and mutarotation equilibrium prevent the complete recovery of glucose under the conditions of the experiment. Calibrations are reproducible from day to day and week to week. Reagents and the PFF constitute a negligible titration blank. Only 1 calculation is necessary. A simplified apparatus and procedure for the preparation of PFF’s permits 15 manual determinations per hour. Coulometric assays of commercial serum controls are accurate to within 3-4%. Data indicate that the precision of the coulometric method exceeds that of the Auto-Analyzer, Folin-Wu, Glucostat, and Nelson-Somogyi procedures. The proposed method is free from interferences at normal serum levels.

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.

scholarly journals Preparation of some immobilized linked enzyme systems and their use in the automated determination of disaccharides

1974 ◽  
Vol 137 (1) ◽  
pp. 25-32 ◽  
Author(s):  
D. J. Inman ◽  
W. E. Hornby
Keyword(s):  
Glucose Oxidase ◽  
Enzyme System ◽  
Inside Surface ◽  
Enzyme Systems ◽  
Nylon Tube ◽  
In Series ◽  
Automated Determination

1. Glucose oxidase (EC 1.1.3.4), amyloglucosidase (EC 3.2.1.3), invertase (EC 3.2.1.26) and β-galactosidase (EC 3.2.1.23) were covalently attached via glutaraldehyde to the inside surface of nylon tube. 2. The linked enzyme system, comprising invertase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of sucrose. 3. The linked enzyme system, comprising β-galactosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of lactose. 4. The linked enzyme system, comprising amyloglucosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of maltose. 5. Mixtures of glucose oxidase and amyloglucosidase were immobilized within the same piece of nylon tube and used for the automated determination of maltose. 6. Mixtures of glucose oxidase and invertase were immobilized within the same piece of nylon tube and used for the automated determination of sucrose.

scholarly journals Determination of Polyhexamethylene Biguanide Hydrochloride Using a Lactone-Rhodamine B-Based Fluorescence Optode

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 262
Author(s):  
Akane Funaki ◽  
Yuta Horikoshi ◽  
Teruyuki Kobayashi ◽  
Takashi Masadome
Keyword(s):  
Fluorescence Intensity ◽  
Sodium Salt ◽  
Contact Lens ◽  
Rhodamine B ◽  
Determination Method ◽  
Polyhexamethylene Biguanide ◽  
Poly Vinyl Chloride ◽  
Nitrophenyl Octyl Ether ◽  
Optode Membrane

A new determination method for polyhexamethylene biguanide hydrochloride (PHMB) using a lactone-rhodamine B (L-RB) based fluorescence optode has been developed. The optode membrane consists of 2-nitrophenyl octyl ether as a plasticizer, L-RB, and poly (vinyl chloride). The optode responds to tetrakis (4-fluorophenyl) borate, sodium salt (NaTPBF) in the μM range. The fluorescence intensity of the L-RB film for PHMB solution containing 20 μM NaTPBF decreased linearly as the concentration of the PHMB solution increased in the concentration range from 0 to 8.0 μM, which shows that PHMB with a concentration range of 0 to 8.0 μM is determined by the L-RB film optode. The concentration of PHMB in the contact lens detergents by the proposed method was in accord with its nominal concentration.

Enzyme thermistor determination of glucose in serum using immobilized glucose oxidase

1977 ◽  
Vol 81 (2) ◽  
pp. 163-175 ◽  
Author(s):  
B. Danielsson ◽  
Kerstin Gadd ◽  
B. Mattiasson ◽  
K. Mosbach
Keyword(s):  
Glucose Oxidase ◽  
Immobilized Glucose Oxidase ◽  
Enzyme Thermistor
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