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 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 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 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 lysine in pharmaceutical sample

2002 ◽  
Vol 67 (11) ◽  
pp. 783-792 ◽  
Author(s):  
Snezana Mitic ◽  
Gordana Miletic ◽  
A.N. Petrovic ◽  
Snezana Tosic
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Reaction Rate ◽  
Kinetic Equations ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Kinetic Determination ◽  
Pharmaceutical Sample ◽  
Alkaline Buffer Solution

Akinetic method for the determination of micro quantities of the amino acid lysine (Lys) is described in this paper. The catalytic activity of cobalt in the reaction of the oxidation of purpurin (1,2,4-trihydroxyanthraquinone PP) by hydrogen peroxide in alkaline buffer solution decreases in the presence of micro quantities of lysine, because of the formation of a complex.1,2 The experimental conditions for the successful determination of lysine were optimized. The relative error ranges from 7.7 to 1.9% in the concentration range from 0.118 to 23.520?g cm-3. The detection limit is 0.023?g cm-3. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions and amino acids on the reaction rate were determined in order to assess the selectivity of the method. The method was applied to the determination of lysine in a pharmaceutical sample Riborn-P (Medecon?Belgrade).

scholarly journals Kinetic determination of ultramicro amounts of As(III) in solution

2003 ◽  
Vol 68 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Aleksandar Igov ◽  
Ranko Simonovic ◽  
Rangel Igov
Keyword(s):  
Catalytic Activity ◽  
Hydrochloric Acid ◽  
Relative Error ◽  
Catalytic Reaction ◽  
Reaction Rate ◽  
Kinetic Method ◽  
Kinetic Equations ◽  
Optimal Conditions ◽  
Kinetic Determination

A new catalytic reaction is proposed and a kinetic method developed for the determination of ultramicro amounts of As(III) on the basis of its catalytic activity in the oxidation of ethylenediamine-N,N?-diacetic-N,N? dipropionic acid (EAP) by KMnO4 in the presence of hydrochloric acid. Under optimal conditions, the sensitivity of the method is 20 ng/cm3. The probable relative error is 7.6 ? 14.5 % for the concentration range 50 ? 200 ng/cm3 As(III). The effect of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The method has relatively good selectivity. Kinetic equations were proposed for the investigated process.

scholarly journals Kinetic determination of ultramicro amounts of thiocyanate

2002 ◽  
Vol 2 (4) ◽  
pp. 209-213
Author(s):  
Vladimir Igov ◽  
Ranko Simonovic ◽  
Rangel Igov
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Equation ◽  
Relative Error ◽  
Kinetic Method ◽  
Kinetic Determination ◽  
Concentration Interval

A kinetic method is suggested for determing traces of thiocyanate on the basis of their activating effect on the Fe(III) catalysis of oxidation of 4-amino-N,Ndiethylaniline sulphate (ANNS) by hydrogen-peroxide. The sensitivity of the method is 50 ng/cm3. The probably relative error ranges between 5,5-10,5% for concentration interval 300-70 ng/cm3 NCS-. Kinetic equation were proposed for the investigated process. The method has relatively good selectivity.

scholarly journals A kinetic method for the determination of phenol

2002 ◽  
Vol 67 (10) ◽  
pp. 661-667 ◽  
Author(s):  
Snezana Mitic ◽  
Valentina Zivanovic
Keyword(s):  
Standard Deviation ◽  
River Water ◽  
Reaction Rate ◽  
Kinetic Method ◽  
Potassium Periodate ◽  
Experimental Conditions ◽  
Inhibiting Effect ◽  
Relative Standard ◽  
Kinetic Expression

Akinetic method for the determination of phenol is proposed. The method is based on the inhibiting effect of phenol on the Mn(II) catalysis of the oxidation of malachite green with potassium periodate. The reaction rate was followed spectrophotometrically at 615 nm. Kinetic expression for the reaction in the presence and absence of phenol are postulated. The optimal experimental conditions for the determination of phenol were established and phenol was determined in concentrations from 30.0 to 188.0 ng/cm3 with a relative standard deviation of 5.5%. The lower detecton limit is 7.8 ng/cm3. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The method was applied for the determination of phenol in tap and river water.

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.

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