scholarly journals OXIDATION KINETICS AND QUANTIFICATION METHOD OF CHOLESTEROL USING CHOLESTEROL OXIDASE ENZYME CATALYST

2010 ◽  
Vol 10 (1) ◽  
pp. 96-101
Author(s):  
Iip Izul Falah ◽  
Ritmaleni Ritmaleni ◽  
M. Utoro Yahya
Keyword(s):  
Hydrogen Peroxide ◽  
Complex Compound ◽  
Oxidation Kinetics ◽  
Cholesterol Oxidase ◽  
Cholesterol Oxidation ◽  
Analysis Method ◽  
Kinetics Analysis ◽  
Thiocyanate Ion ◽  
Quantification Method ◽  
Oxidase Enzyme

In view of health, cholesterol is believed as one of many sources can raise several diseases. Hence, both of research in quantification and developing simple, rapid and accurate analysis method of cholesterol in a sample is very important. Aim of this research was to investigate cholesterol oxidation kinetics and its quantification method based on oxidation of cholesterol and formation complex compound of hexathiocyanato ferat(III), {Fe(SCN)6}-3. The kinetics analysis and quantification, involved cholesterol oxidation in 0.1 M and pH 7.0 phosphate buffer solution to produce cholest-4-en-3-one and hydrogen peroxide, in the presence of cholesterol oxidase enzyme. The formed hydrogen peroxide was used to oxidize iron(II) ion, which was reacted furthermore with thiocyanate ion to raise the red-brown complex compound. Results of the study showed that the complex was stable at 10-120 min since the reaction was started, with maximum wavelength of 530-540 nm. While the kinetics analysis gave first order oxidation reaction with a reaction rate constant, kapp = 5.22 x 10-2 min-1. Based on this kinetics data, cholesterol analysis method could be developed i.e. by oxidizing cholesterol within 1.5 h using cholesterol oxidase as a catalyst, and then reacted with Fe2+, in a solution containing thiocyanate ion. Absorbencies of solutions of the complex compound, measured at wavelength of 535 nm, were linearly proportional to their cholesterol concentrations, in the range of 50-450 ppm.   Keywords: cholesterol, quantification, kinetics, hexathiocyanato ferat(III)

Kinetic study of cholesterol oxidation by cholesterol oxidase enzyme as application for cholesterol biosensor

2019 ◽  
Author(s):  
Meka Saima Perdani ◽  
Muhamad Sahlan ◽  
Siti Farida ◽  
Dwini Normayulisa Putri ◽  
Sri Angky Soekanto ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Cholesterol Oxidase ◽  
Cholesterol Oxidation ◽  
Oxidase Enzyme ◽  
Cholesterol Biosensor

scholarly journals Hydrogen Peroxide Oxidation of Coordinated Thiocyanate Ion in cis- and trans-[Coen2NH3NCS]2+: The Preparation and Properties of trans-[Coen2NH3CN]2+

1973 ◽  
Vol 51 (24) ◽  
pp. 4152-4158 ◽  
Author(s):  
Albert Richard Norris ◽  
James William Lennox Wilson
Keyword(s):  
Hydrogen Peroxide ◽  
Spectral Properties ◽  
Peroxide Oxidation ◽  
Reaction Conditions ◽  
Thiocyanate Ion ◽  
Hydrogen Peroxide Oxidation ◽  
Percent Conversion ◽  
Cis And Trans ◽  
In Cis

The hydrogen peroxide oxidation of thiocyanate ion in cis- and trans-[Coen2NH3NCS]2+ leads to the formation of the corresponding cis- and trans-cyanoammine- and diamminebis(ethylenediamine)cobalt-(III) complexes. The spectral properties of the previously unreported trans-[Coe2NH3CN]2+ are reported and compared to the spectral properties of the cis-isomer.Observations are made concerning the reaction conditions which favor a high percent conversion of trans-[Coen2NH3NCS]2+ to trans-[Coen2NH3CN]2+.

scholarly journals ELIMINASI GANGGUAN MATRIKS DALAM ANALISIS MERKURI HG SEBAGAI SENYAWA KOMPLEKS THIO MICHLER’S KETON SECARA SPEKTROFOTOMETRI

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Sukib Sukib ◽  
Muti'ah Muti'ah
Keyword(s):  
Solvent Extraction ◽  
River Water ◽  
Complex Compound ◽  
Limit Of Detection ◽  
Standard Addition ◽  
Analysis Method ◽  
Addition Method ◽  
Matrix Interferences ◽  
Mercury Analysis

Abstrak. Telah dilakukan penelitian tentang penyusunan metode analisis merkuri melalui pembentukan senyawa kompleks dengan 4,4'-Bis(dimethylamino)thio-benzophenone TMK. Senyawa kompleks tersebut berwarna biru kehijauan yang dapat dideteksi dengan  spektrofoto-meter pada kondisi: lmax 574 nm;  pH 3; konsentrasi TMK 0,0002 M, dan waktu tunggu selama 4–10 menit. perbandingan volume pereaksi: Hg(II), bufer pH 3, TMK 0,002 M, H2O bebas ion adalah 1:1:1:7. Dari hasil penelitian menunjukkan bahwa metode ini telah memenuhi validitas, yaitu: linieritas 0,05–2,0 mg/L, limit deteksi 0,008 mg/L, dan % recovery antara 98% – 102%. Gangguan matriks akibat adanya ion–ion Au(III), Ag(I), Pd(II), Cu(II), Co(II), dan Fe(II) dapat dieliminasi dengan metode ekstraksi pelarut dan adisi standar. Metode adisi standar terbukti mampu memberikan data hasil pengukuran yang dapat dipercaya pada a 5%, yaitu untuk sampel buatan sebesar (0,053 ± 0,001) mg/L, air sungai (0,034 ± 0,004) mg/L, dan sedimen sebesar (4,172 ± 0,050) mg/kg. Dari hasil penelitian ini dapat disimpulkan bahwa metode ekstraksi pelarut dan adisi standar mampu mengeliminasi gangguan matriks pada analisis merkuri sebagai kompleks Hg-TMK secara spektrofotometriKata kunci: Metode analisis merkuri, Thio Michler’s keton, eliminasi, gangguan matriks  Abstract. A research  of analysis method for determination of mercury through formation of complex with 4,4'-bis(dimethylamino)thiobenzophenone TMK has been conducted. The green blue complex compound can be detected with spectrophoto-meter in conditions: lmax 574 nm, buffer acetate pH 3, concentration of TMK 0,0002 M, and the absorbance of complex remains stable for 4–10 minutes. The formula of reagents volume for: Hg(II): buffer acetate pH 3: TMK 0,002 M : de-ionized water is 1:1:1:7. This method is valid, with parameters such as linearity 0.05–2.00 mg/L, limit of detection 0.008 mg/L, and recovery in the range 98%-102%. Matrix interferences that are caused by Au(III), Ag(I), Pd(II), Cu(II), Co(II), and Fe(III) ions can be eliminated with solvent extraction and standard addition methods. Standard addition method is able to give data of trusty measurement result at a 5%, that is for synthesis sample as (0.053 ±  0.001) mg/L, river water (0.034 ± 0.004) mg/L, and for sediment (4.172 ± 0.050) mg/kg. From the result of this research, it can be concluded that solvent extraction and standard addition methods are able to eliminated matrix interferences in mercury analysis as Hg-TMK complex spectrophotometrically Key waords: mercury analysis method, Thio Michler’s ketone, elimination, matrix interferences

Dry film for the enzymic determination of total cholesterol in serum.

1982 ◽  
Vol 28 (5) ◽  
pp. 1159-1162 ◽  
Author(s):  
G M Dappen ◽  
P E Cumbo ◽  
C T Goodhue ◽  
S Y Lynn ◽  
C C Morganson ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cholesterol Oxidase ◽  
Comparison Method ◽  
Total Serum ◽  
Total Serum Cholesterol ◽  
Gelatin Layer ◽  
Control Fluid ◽  
Hydrolysis Of ◽  
Dry Film

Abstract We have prepared a dry film for the enzymic determination of total serum cholesterol. It consists of a transparent support bearing a buffered gelatin layer, and a white reflective spreading layer that contains all of the necessary components for the detection of cholesterol. The method is based on (a) hydrolysis of cholesterol esters to cholesterol by cholesterol ester hydrolase (EC 3.1.1.13), (b) oxidation of cholesterol to cholest-4-en-4-one and hydrogen peroxide by cholesterol oxidase (EC 1.1.3.6), and (c) oxidation of a triarylimidazole leuco dye with hydrogen peroxide in the presence of peroxidase (EC 1.11.1.7) to produce a dye with maximum absorption at about 650 nm. For use over a wider range of concentration, the dye density is read at 540 nm. With reflection densitometry and appropriate mathematical transformation, readings and cholesterol concentrations are linearly related to 5500 mg/L. Results correlate well with those by the Abell-Kendall comparison method (slope 0.97, intercept 92.5, correlation coefficient 0.974, Sy.x = 250.7), and the method is precise (CV of 1.2-2.3% for a control fluid and patients' samples) and relatively free of interferences.

Oxidation kinetics of two pesticides in natural waters by ozonation and ozone combined with hydrogen peroxide

2011 ◽  
Vol 45 (8) ◽  
pp. 2517-2526 ◽  
Author(s):  
Pamela Chelme-Ayala ◽  
Mohamed Gamal El-Din ◽  
Daniel W. Smith ◽  
Craig D. Adams
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidation Kinetics ◽  
Natural Waters ◽  
Kinetics Of

Photocatalytic Degradation of 2,4,5–TCP in TiO2/UV/H2O2 System

2012 ◽  
Vol 518-523 ◽  
pp. 2649-2652
Author(s):  
Yan Ping Zong ◽  
Xian Hua Liu ◽  
Xi Wen Du ◽  
Yi Ren Lu ◽  
Xiao Xuan Shi
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Degradation ◽  
Absorption Spectroscopy ◽  
Degradation Mechanism ◽  
Analysis Method ◽  
Photocatalytic System ◽  
Initial Ph ◽  
Effects Of Ph

The photocatalytic degradation of 2,4,5–Trichlorophenol(2,4,5–TCP) in TiO2/UV/ H2O2 photocatalytic system was examined using absorption spectroscopy and GC-MS. It was found that 2,4,5–TCP could be degraded almost completely within 100 min under the conditions of initial pH 3, C(H2O2) = 0.08 mol/L and C(TiO2) = 0.5 g/L. The effects of pH and the concentration of hydrogen peroxide on the degradation of 2,4,5–TCP were also studied. Besides, the degradation mechanism was concluded accorrding to convertional analysis method too.

One-minute electrochemical enzymic assay for cholesterol in biological materials.

1981 ◽  
Vol 27 (12) ◽  
pp. 1978-1982 ◽  
Author(s):  
L C Clark ◽  
C A Duggan ◽  
T A Grooms ◽  
L M Hart ◽  
M E Moore
Keyword(s):  
Hydrogen Peroxide ◽  
Cholesterol Oxidase ◽  
Density Lipoprotein ◽  
Cholesterol Esters ◽  
Unesterified Cholesterol ◽  
Polycarbonate Membrane ◽  
Platinum Anode ◽  
Tissue Homogenates ◽  
Enzymic Assay ◽  
Kendall Method

Abstract In this rapid and specific micro-scale electrochemical enzymic assay for cholesterol and cholesterol esters, 10 microL of standard or sample is injected directly into a heated (50 degrees C) thermostated, oxystated cuvet containing pH 7.25 buffer, cholesterol oxidase (EC 1.1.3.6), and cholesterol esterase (EC 3.1.1.13). The cholesterol esters are hydrolyzed by the esterase, and the cholesterol is simultaneously oxidized by the oxidase. The hydrogen peroxide produced from oxidation of the unesterified cholesterol is measured by a polarographic anode covered with an acetate/polycarbonate membrane. The membrane allows hydrogen peroxide to diffuse to the platinum anode, where it is oxidized, but prevents the diffusion of ascorbic acid, uric acid, and bilirubin to the electroactive surface. Turbidity does not interfere. The correlation (r) between results by our method and the Abell-Kendall method for 105 samples of serum was 0.9994 and for 105 samples of plasma was 0.9997. Our method is convenient for the analysis of high-density lipoprotein cholesterol in plasma and serum supernates and in many kinds of tissue homogenates. Its limitations are also described.

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