scholarly journals Kinetic determination of morin nanoamounts

2004 ◽  
Vol 69 (6) ◽  
pp. 477-484 ◽  
Author(s):  
Danijela Kostic ◽  
Snezana Mitic ◽  
Gordana Miletic
Keyword(s):  
Reaction Rate ◽  
Limit Of Detection ◽  
Kinetic Equations ◽  
Calibration Graph ◽  
Linear Calibration ◽  
Kinetic Determination ◽  
Concentration Interval ◽  
Kinetic Spectrophotometric ◽  
The Given

kinetic-spectrophotometric method is proposed for the determination of morin. The method is based on the inhibition effect of morin on the oxidation of C6H5COON aby hydrogen peroxide in the presence of the complex Fe(II)-AA(ascorbic acid),which acts as a catalyst. The concentration range for the determination of morin is one of the lowest achieved so far (a linear calibration graph was obtained for morin from 2.255?22.55 ng cm-3). The limit of detection of the method is 0.28 ng cm-3. The relative error ranges between 1.42 to 5.10% for the given concentration interval. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions upon the reaction rate were determined in order to assess the selectivity of the method. The major advantages of this kinetic-spectrophotometric assay are its sensitivity, selectivity, reproducibility, speed and simplicity.

scholarly journals Kinetic determination of rutin

2001 ◽  
Vol 66 (3) ◽  
pp. 205-211
Author(s):  
S.S. Mitic ◽  
J.I. Vucetic ◽  
S.M. Miletic ◽  
D.A. Kostic
Keyword(s):  
Hydrogen Peroxide ◽  
Detection Limit ◽  
Relative Error ◽  
Reaction Rate ◽  
Kinetic Equations ◽  
Inhibitory Effect ◽  
Kinetic Determination ◽  
Hydrogen Peroxide Detection ◽  
Concentration Interval

Akinetic method is described for the determination of rutin based on its inhibitory effect on the Fe(II)-AA catalysis of the oxidation of C6H5COONa with hydrogen peroxide. Detection limit of this method is 0.16 ngcm-3. The relative error ranges between 0.9 to 9.8%for the concentration interval 0.82 ngcm-3 to 8.2 ngcm-3. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method.

scholarly journals Kinetic determination of Se(IV) in pharmaceutical samples

2000 ◽  
Vol 65 (8) ◽  
pp. 595-601
Author(s):  
S.S. Mitic ◽  
J.I. Vucetic ◽  
S.M. Miletic ◽  
D.A. Kostic
Keyword(s):  
Hydrogen Peroxide ◽  
Detection Limit ◽  
Reaction Rate ◽  
Kinetic Method ◽  
Kinetic Equations ◽  
Kinetic Determination ◽  
Pharmaceutical Samples ◽  
Inhibiting Effect ◽  
Concentration Interval

A kinetic method is described for the determination of Se(IV) based on its inhibiting effect on the Fe(III) catalysis of the oxidation of C6H5COONa with hydrogen peroxide. The detection limit is 0.06 pg cmT The relative error ranges between 2.1 and 9.5 % for the concentration interval 0.26 to 2.6 ?g cm-3. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions upon the reaction rate were determined in order to assess the selectivity of the method. The method was applied for the determination of Se(IV) in pharmaceutical samples.

scholarly journals Kinetic determination of ultramicro amounts of Cu(II) ion in solution

2003 ◽  
Vol 68 (3) ◽  
pp. 219-226 ◽  
Author(s):  
Zora Grahovac ◽  
Snezana Mitic ◽  
Emilija Pecev
Keyword(s):  
Hydrogen Peroxide ◽  
Detection Limit ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Kinetic Method ◽  
Kinetic Equations ◽  
Kinetic Determination ◽  
Concentration Interval ◽  
Ponceau 4R

A new kinetic method is described for the determination of ultramicro amounts of Cu(II) based on its catalytic effect on the oxidation of trisodium-2-hydroxy 1-(4-sulphonato-1-naphthylazo)naphthalene-6,8-disulphonato (red artificial color PONCEAU 4R) by hydrogen peroxide in borate buffer (B.B). The detection limit given by Perez-Bendito is 0.8 ng/cm3, but the detection limit that we experimentaly determined is 3.8 ng/cm3. The relative error ranges between 7.77 and 2.09%for the concentration interval 3.8 to 50.1 ng/cm3. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions upon the reaction rate were determined for an assessment of the selectivity of the method. The method was applied for the determination of Cu(II) ions in samples of alloy.

scholarly journals Kinetic determination of As(III) in solution

2003 ◽  
Vol 68 (10) ◽  
pp. 765-769
Author(s):  
Sofija Rancic ◽  
Rangel Igov ◽  
Todor Pecev
Keyword(s):  
Acid Solution ◽  
Relative Error ◽  
Reaction Rate ◽  
Kinetic Method ◽  
Kinetic Equations ◽  
Strong Acid ◽  
Kinetic Determination

A new reaction is suggested and a new kinetic method is elaborated for the As(HI) traces determination in solution, on the basis of their catalyzing effect on komplexon III (EDTA) oxidation by KMnO4 in a strong acid solution (H2SO4). Using a spectrophotometric technique, a sensitivity of 72 ng/cm3 As(IIl) was achieved. The relative error of method varies from 5.5 to 13.9 % for As(HT) concentration range from 83 to 140 ng/cm-1. Appropriate kinetic equations are formulated and the influence of some other ions, including the As(V), upon the reaction rate is tested.

scholarly journals New indicator reaction for kinetic determination of micro amounts of Sn(II)

2001 ◽  
Vol 66 (9) ◽  
pp. 631-636
Author(s):  
Rangel Igov ◽  
Violeta Mitic ◽  
Todor Pecev ◽  
Vesna Stankov-Jovanovic
Keyword(s):  
Kinetic Equation ◽  
Ammonium Chloride ◽  
Crystal Violet ◽  
Reaction Rate ◽  
Kinetic Determination ◽  
Inhibiting Effect ◽  
Dimethyl Ammonium Chloride ◽  
Concentration Interval ◽  
Dimethyl Ammonium

A new reaction is suggested and a new method is elaborated for determination of micro amounts of Sn(II) based on its inhibiting effect on the oxidation of {4-bis[n-(dimethylamino) phenyl]methylene-2,5-cyclohexadiene-1-ilydene}dimethyl-ammonium chloride (crystal violet CV) by H2O2. The method sensibility is 0.4 ?g/cm3. The probable relative error is 2.8-12.8 % for Sn(II) in the concentration interval of 3 to 0.8 ?g/cm3. The kinetic equation for this process is given. The influence of some other ions on the reaction rate was tested. The method was applied to the determination of Sn(II) in a sample of microalloy.

scholarly journals Kinetic spectrophotometric determination of Bi(III) based on its catalytic effect on the oxidation of phenylfluorone by hydrogen peroxide

2009 ◽  
Vol 74 (8-9) ◽  
pp. 977-984
Author(s):  
Sofija Rancic ◽  
Snezana Nikolic-Mandic
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Determination ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Kinetic Method ◽  
Limit Of Quantification ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A new reaction was suggested and a new kinetic method was elaborated for determination of Bi(III) in solution, based on its catalytic effect on the oxidation of phenyl-fluorone (PF) by hydrogen peroxide in ammonia buffer. By application of spectrophotometric technique, a limit of quantification (LQ) of 128 ng cm-3 was reached, and the limit of detection (LD) of 37 ng cm-3 was obtained, where LQ was defined as the ratio signal: noise = 10:1 and LD was defined as signal 3:1 against the blank. The RSD value was found to be in the range 2.8-4.8 % for the investigated concentration range of Bi(III). The influence of some ions upon the reaction rate was tested. The method was confirmed by determining Bi(III) in a stomach ulcer drug ('Bicit HP', Hemofarm A.D.). The obtained results were compared to those obtained by AAS and good agreement of results was obtained.

scholarly journals Kinetic- spectrophotometric Method for the Determination of Naringenin in Pure and Supplements Formulations

2019 ◽  
Vol 16 (3) ◽  
pp. 0595
Author(s):  
ALmashhadani Et al.
Keyword(s):  
Prussian Blue ◽  
Correlation Coefficient ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Calibration Graph ◽  
Maximum Absorbance ◽  
Kinetic Spectrophotometric

          Simple, cheap, sensitive, and accurate kinetic- spectrophotometric method has been developed for the determination of naringenin in pure and supplements formulations. The method is based on the formation of Prussian blue. The product dye exhibits a maximum absorbance at 707 nm. The calibration graph of naringenin was linear over the range 0.3 to 10 µg ml-1 for the fixed time method (at 15 min) with a correlation coefficient (r) and percentage linearity (r2%) were of 0.9995 and 99.90 %, respectively, while the limit of detection LOD was 0.041 µg ml-1. The method was successfully applied for the determination of naringenin in supplements with satisfactory results.

scholarly journals Kinetic-Spectrophotometric Determination of Iodide Based on its Inhibitory Effect on the Decolorization Reaction of Methyl Orange

2009 ◽  
Vol 6 (4) ◽  
pp. 1267-1273
Author(s):  
Reyhaneh Rahnama Kozani ◽  
Ferydoun Ashrafi ◽  
Masuod Khalilnezhad ◽  
Mohammad Reza Jamali
Keyword(s):  
Methyl Orange ◽  
Spectrophotometric Determination ◽  
Limit Of Detection ◽  
Inhibitory Effect ◽  
Calibration Graph ◽  
Reaction Products ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple, sensitive, rapid and reliable method has been developed for spectrophotometric determination of iodide based on its inhibition effect on the redox reaction between bromate and hydrochloric acid. The decolorization of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 525 nm. The variables affecting the rate of the reaction were investigated. Under the optimum conditions, the limit of detection is 1.5 × 10-7mol L-1and calibration range is 2.0 × 10-6–1.3 × 10-4mol L-1of iodide. The linearity range of the calibration graph is depends on bromate concentration. The relative standard deviation of ten-replication determination of 8.2 × 10-5mol L-1iodide was 1.4%. The proposed method was applied to the determination of iodide in natural water samples with satisfactory results.

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.

A novel kinetic-spectrophotometric method for determination of nitrites in water

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Zenovia Moldovan
Keyword(s):  
Kinetic Method ◽  
Calibration Graph ◽  
Linear Calibration ◽  
Nitrite Concentration ◽  
Experimental Conditions ◽  
Sulfuric Acid Medium ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Drinking Water Samples

AbstractA simple, selective and sensitive kinetic method for the determination of nitrite in water was developed. The method is based on the catalytic effect of nitrite on the oxidation of methylene blue (MB) with bromate in a sulfuric acid medium. During the oxidation process, absorbance of the reaction mixture decreases with the increasing time, inversely proportional to the nitrite concentration. The reaction rate was monitored spectrophotometrically at λ = 666 nm within 30 s of mixing. Linear calibration graph was obtained in the range of 0.005–0.5 μg mL−1 with a relative standard deviation of 2.09 % for six measurements at 0.5 μg mL−1. The detection limit was found to be 0.0015 μg mL−1. The effect of different factors such as acidity, time, bromate concentration, MB concentration, ionic strength, and order of reactants additions is reported. Interference of the most common foreign ions was also investigated. The optimum experimental conditions were: 0.38 mol L−1 H2SO4, 5 × 10.4 mol L−1 KBrO3, 1.25 × 10.5 mol L−1 MB, 0.3 mol L−1 sodium nitrate, and 25°C. The proposed method was conveniently applied for the determination of nitrite in spiked drinking water samples.

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