scholarly journals The development of a new inhibition kinetic spectrophotometric method for the determination of phenylhydrazine

2005 ◽  
Vol 70 (7) ◽  
pp. 987-993 ◽  
Author(s):  
Violeta Mitic ◽  
Snezana Nikolic ◽  
Vesna Stankov-Jovanovic
Keyword(s):  
Detection Limit ◽  
Rate Equation ◽  
Reaction Rate ◽  
Method Development ◽  
Kinetic Method ◽  
Inhibitory Effect ◽  
Reagent Concentration ◽  
Inhibition Kinetic ◽  
Kinetic Spectrophotometric

Anew sensitive kinetic method has been developed for the determination of trace amounts of phenylhydrazine in the range of 1.08x10-7 to 1.08x10-6 g/cm3. The detection limit of this method is 0.008 ?g/cm3, based on the 3Sb criterion. Themethod is based on the inhibitory effect of phenylhydrazine on the oxidation of Victoria Blue 4-R by KBrO3. The reaction was monitored spectrophotometrically at 596.3 nm. The method development includes the optimization of the reagent concentration and temperature. The kinetic parameters of the reaction are reported and a rate equation is suggested. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The new developed method was found to have fairly good selectivity, sensitivity, simplicity and rapidity.

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 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 Thionine-Bromate as a New Reaction System for Kinetic Spectrophotometric Determination of Hydrazine in Cooling Tower Water Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Masoud Reza Shishehbore ◽  
Ali Sheibani ◽  
Masoumeh Eslami
Keyword(s):  
Water Samples ◽  
Kinetic Method ◽  
Reaction System ◽  
Fixed Time ◽  
Inhibitory Effect ◽  
Optimum Conditions ◽  
Acid Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple, selective, and inexpensive kinetic method was developed for the determination of hydrazine based on its inhibitory effect on the thionine-bromate system in sulfuric acid media. The reaction was monitored spectrophotometrically at 601 nm by a fixed time method. The effect of different parameters such as concentration of reactants, ionic strength, temperature, and time on the rate of reaction was investigated, and the optimum conditions were obtained. Under optimum conditions, the calibration curve was linear in the concentration range from 0.8–23.0 μg mL−1of hydrazine, and the detection limit of the method was 0.22 μg mL−1. The relative standard deviation for five replicate determinations of 1.0 μg mL−1of hydrazine was 0.74%. The potential of interfering effect of foreign species on the hydrazine determination was studied. The proposed method was successfully applied for the determination of hydrazine in different water samples.

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 The Development of a New Inhibition Kinetic Spectrophotometric Method for the Determination of Phenylhydrazine Based on its Inhibitory Effect on Oxidation of Methyl Red by Bromate in Micellar Medium

2010 ◽  
Vol 7 (4) ◽  
pp. 1591-1597
Author(s):  
Mohsen Keyvanfard
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Fixed Time ◽  
Inhibitory Effect ◽  
Methyl Red ◽  
Micellar Medium ◽  
Relative Standard ◽  
Inhibition Kinetic ◽  
Kinetic Spectrophotometric

A new, simple, sensitive and selective kinetic spectrophotometric method was developed for the determination of trace amounts of phenylhydrazine over the range of 0.02-0.30 μg/mL. The method is based on the inhibitory effect of phenylhydrazine on the oxidation of methyl red by bromate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of methyl red at 518 nm with a fixed-time 0.5–2.0 min from initiation of the reaction..The relative standard deviation of 0.08 and 0.2 μg/mL phenylhydrazine was 1.7 and 2.4%, respectively. The method was applied to the determination of phenylhydrazine in water samples.

scholarly journals A kinetic method for para-nitrophenol determination based on its inhibitory effect on the catalatic reaction of catalase

2005 ◽  
Vol 3 (4) ◽  
pp. 592-604 ◽  
Author(s):  
Claudia Mureşanu ◽  
Lucian Copolovici ◽  
Florina Pogącean
Keyword(s):  
Detection Limit ◽  
Phenolic Compounds ◽  
Catalytic Reaction ◽  
Initial Rate ◽  
Kinetic Method ◽  
Inhibitory Effect ◽  
Inhibition Mechanism ◽  
Kinetic Determination ◽  
Menten Kinetic

AbstractThe inhibitory effect of para-nitrophenol on the catalytic reaction of catalase was investigated. Michaelis-Menten kinetic parameters were determined from Lineweaver-Burk plots obtained in the absence or in the presence of the inhibitor. The inhibitor pattern, revealed by the Lineweaver-Burk plots, suggested a fully mixed inhibition mechanism. Spectrophotometric monitoring of the indicator reaction: $$H_2 O_2 \xrightarrow{{catalase,para - nitrophenol}}H_2 O + \tfrac{1}{2}O_2 $$ in conjunction with initial rate measurements was employed for the kinetic determination of the inhibitor. Calibration plots of initial rate vs. para-nitrophenol concentration were linear in the concentration range 0.9·10−5–2.5·10−5 mol/L and the detection limit was 3·10−6 mol/L (417 μg/L) para-nitrophenol. Interferences from other phenolic compounds like orto-cresole, meta-and orto-nitrophenol were observed.

Alcohol Determination by HPLC with Postcolumn Derivatization Based on the Thiosulfate-catalyzed Reaction of Alcohols and Cerium(IV) and Fluorescence Detection of Cerium(III)

2020 ◽  
Vol 16 ◽  
Author(s):  
Ikko Mikami ◽  
Eri Shibayama ◽  
Kengo Takagi
Keyword(s):  
Detection Limit ◽  
Fluorescence Detection ◽  
Reaction Rate ◽  
Detection Method ◽  
Fluorescence Detector ◽  
Reaction Solution ◽  
Optimum Detection ◽  
Postcolumn Derivatization ◽  
Sensitive Method

Background: Determination of a reducing substance based on the reaction between Ce(IV) and a reducing substance and fluorescence detection of Ce(III) generated has been reported as a selective and sensitive method. However, this method could not be applied to the determination of alcohol due to the low reaction rate of alcohol and Ce(IV). Objective: We found that thiosulfate catalytically enhanced reaction of alcohols (such as, methanol, ethanol, and propanol) and Ce(IV). Utilizing this effect, we developed a new method for the determination of alcohols. Results: In the presence of thiosulfate, an increase in fluorescence intensity was detected by injecting alcohol at concentrations of several millimolar, whereas it was not observed even at the concentration of 10% v/v (2 M for ethanol) in the absence of thiosulfate. The optimum detection conditions were determined to be 4.0 mM Ce(IV) sulfate and 0.50 mM thiosulfate, and the detection limit (S/N = 3) of ethanol under these conditions was 1 mM. In the calibration curves, changes in the slope were observed when the alcohol concentrations were approximately 10–25 mM. Using a thiosulfate solution containing ethanol as the reaction solution, a calibration curve without any change in slope was obtained, although the concentration of ethanol at the detection limit increased. The alcohols in the liquor and fuel were successfully analyzed using the proposed detection method as a postcolumn reaction. Conclusion: This new alcohol detection method using a versatile fluorescence detector can be applied to the postcolumn reaction of HPLC omitting need of time-consuming pretreatment processes.

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 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.

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