scholarly journals A New Inhibition Kinetic Spectrophotometric Method for the Determination of Resorcinol

2010 ◽  
Vol 7 (3) ◽  
pp. 727-732
Author(s):  
Mohsen Keyvanfard
Keyword(s):  
Spectrophotometric Method ◽  
Fixed Time ◽  
Inhibitory Effect ◽  
Cresyl Violet ◽  
Relative Standard ◽  
Fast Kinetic ◽  
Kinetic Spectrophotometric ◽  
Replicate Measurements ◽  
Catalyzed Oxidation

A new, simple, inexpensive and fast kinetic spectrophotometric method was developed for the determination of trace amounts of resorcinol over the range of 0.02-0.80 μg/mL. The method is based on the inhibitory effect of resorcinol on the formaldehyde catalyzed oxidation reaction of of cresyl violet by bromate in acidic media is reported. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of cresyl violet at 596 nm with a fixed-time 0.5–2.5 min from initiation of the reaction.The detection limit is 0.017 μg/mL and relative standard deviation of 0.1 and 0.5 μg/mL resorcinol for six replicate measurements was 2.6 and 2.9 %, respectively. The method was applied to the determination of resorcinol in water samples.

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 The Development of a New Kinetic Spectrophotometric Method for the Determination of Vanadium(V) Based on its Catalytic Effect on the Oxidation of Malachite Green Oxalate by Bromate in Acidic and Micellar Medium

2010 ◽  
Vol 7 (4) ◽  
pp. 1612-1620 ◽  
Author(s):  
M. Keyvanfard ◽  
N. Abedi
Keyword(s):  
Malachite Green ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Micellar Medium ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Malachite Green Oxalate

A new, simple, sensitive and selective kinetic spectrophotometric method was developed for the determination of ultra trace amounts of vanadium(V). The method is based on the catalytic effect of vanadium(V) on the oxidation of malachite green oxalate (MG) by bromate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of malachite green oxalate (MG) at 625 nm with a fixed-time method. The decrease in the absorbance of MG is proportional to the concentration of vanadium(V) in the range of 1-100 ng/mL with a fixed time of 0.5-2 min from the initiation of the reaction. The limit of detection is 0.71 ng/mL of vanadium(V). The relative standard deviation for the determination of 5, 30, 50 ng/mL of vanadium(V) was2.5% 2.6%, 2.4% and respectively. The method was applied to the determination of vanadium(V) in water samples.

Kinetic Spectrophotometric Determination of Ruthenium by its Catalytic Effect on the Reduction of Spadns with Sodium Hypophosphite in Micellar Media

2012 ◽  
Vol 204-208 ◽  
pp. 4067-4070 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Sodium Hypophosphite ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple kinetic spectrophotometric method was developed for the determination of trace amounts of Ru (III). The method is based on the reduction of spadns by sodium hypophosphite (NaH2PO2) in micellar media. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of spadns at 515 nm with a fixed-time method. The decrease in the absorbance of spadns is proportional to the concentration of Ru (III) in the range 0.40–10.0 μg/L with a fixed time of 2.5–7.0 min from the initiation of the reaction. The limit of detection is 0.12 μg/L Ru (III). The relative standard deviation for the determination of 0.10 and 0.20 μg/25mL Ru (III) was 2.3 % and 2.0 %, respectively. The method was applied to the determination of Ru (III) in some ores and metallurgy products.

Kinetic Spectrophotometric Method for the Determination of Selenium (IV) by its Catalytic Effect on the Reduction of Arsenazo III with Sodium Hypophosphite in Micellar Media

2012 ◽  
Vol 554-556 ◽  
pp. 926-933
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Fixed Time ◽  
Sodium Hypophosphite ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple and sensitive kinetic spectrophotometric method for the determination of trace selenium (IV) is described, based on its catalytic effect on the reduction arsenazo III (AsA III) with sodium hypophosphite (NaH2PO2) in a solution of 0.02 mol/L sulfuric acid and in the presence of cationic micellar media. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of AsA III at 550 nm with a fixed-time method. The decrease in the absorbance of AsA III is proportional to the concentration of Se(IV) in the range 0.16–1.0 µg/L after a fixed time of 4–10 min from the initiation of the reaction. The limit of detection is 0.049 µg/L Se(IV). The influence of th e factors such as acidity, concentration of reactants, type and concentration of surfactants, reactive time, temperature and co-existing ions on the reaction is discussed. The optimum reaction conditions of reaction are established and some kinetic parameters are determined; the apparent activation energy of catalytic reaction is 59.51 kJ/mol. The relative standard deviation for eleven replicate determination of 0.02, and 0.01µg/25mL Se(IV) was 2.0 % and 2.4 %, respectively. Combined with sulphydryl dextrane gel (SDG) separation and enriching, the method has been successfully applied to the determination of Se (IV) in foodstuff and human hair samples with the relative standard deviation of 2.1 %–5.8 % and the recovery of 97.0 %–103.3 %, the results are in good agreement with those provided by ICP-AES 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.

Kinetic Spectrophotometric Method for the Determination of Trace Ruthenium(III) by its Catalytic Effect on the Oxidation of Dibromo Caboxy Arsenazo with Bromate in Cationic Micellar Media

2012 ◽  
Vol 602-604 ◽  
pp. 1289-1293 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Fixed Time ◽  
Micellar Medium ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A spectrophotometric method was developed for the determination of trace Ru (III) is described, based on its catalytic effect of Ru (III) on the oxidation of dibromo caboxy arsenazo (DBCAA) by bromate in acidic and micellar medium at 100 °C. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of the catalytic reaction of DBCAA at 530 nm with a fixed-time method. The calibration curve for the recommended method was linear in the concentration range over 0.037–1.0 µg/L and the detection limit of the method for Ru (III) was 0.011 µg/L. The method was applied to the determination of Ru (III) in some ores and metallurgy products. The results are in good agreement with the recommend values with the relative standard deviation of 2.6 %–3.8 % and the recovery of 97.2 %–104.3 %.

A Simple and Sensitive Spectrophotometric Method for the Determination of Trace Ruthenium with its Catalytic Effect on the Oxidation of Rhodamine 6G by KBrO3 in Micellar Media

2012 ◽  
Vol 217-219 ◽  
pp. 2397-2401 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Rhodamine 6G ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Sensitive Spectrophotometric Method

A simple catalytic kinetic spectrophotometric method was developed for the determination of trace Ru (III) in the range of 0.033–1.00 μg/L. The method is based on the catalytic effect of Ru (III) on the oxidation of rhodamine 6G (Rh 6G) by bromate in micellar media. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of Rh 6G at 520 nm with a fixed-time method. The limit of detection is 0.010 μg/L Ru (III). The relative standard deviation for the determination of 0.010 and 0.020 μg/25mL Ru (III) was 2.9 % and 2.5 %, respectively. The method was applied to the determination of Ru (III) in some ores and metallurgy products.

scholarly journals New Kinetic Spectrophotometric Method for Determination of Folic Acid in Pharmaceutical Formulations

2015 ◽  
Vol 50 ◽  
pp. 169-178
Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal
Keyword(s):  
Folic Acid ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Fixed Time ◽  
Rate Data ◽  
Sulfuric Acid Medium ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods

scholarly journals Determination of Sodium Cromoglycate by a New Kinetic Spectrophotometric Method in Biological Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Mohsen Keyvanfard ◽  
Khadijeh Alizad ◽  
Razieh Shakeri
Keyword(s):  
Standard Deviation ◽  
Sodium Cromoglycate ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Micellar Medium ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A new kinetic spectrophotometric method is described for the determination of ultratrace amounts of sodium cromoglycate (SCG). The method based on catalytic action of SCG on the oxidation of amaranth with periodate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the amaranth at 518 nm, for the first 4 min from initiation of the reaction. Calibration curve was linear in the range of 4.0−36.0 ng mL−1SCG. The limit of detection is 2.7 ng mL−1SCG. The relative standard deviation (RSD) for ten replicate analyses of 12, 20, and 28 ng mL−1SCG was 0.40%, 0.32%, and 0.53%, respectively. The proposed method was used for the determination of SCG in biological samples.

scholarly journals A New Kinetic Spectrophotometric Method for the Quantitation of Amorolfine

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
César Soto ◽  
Cristian Poza ◽  
David Contreras ◽  
Jorge Yáñez ◽  
Fallon Nacaratte ◽  
...  
Keyword(s):  
Spectrophotometric Method ◽  
Tap Water ◽  
Fixed Time ◽  
Fungal Cell ◽  
Inhibition Of Growth ◽  
Fungicide Activity ◽  
Dual Inhibition ◽  
Assay Precision ◽  
Kinetic Spectrophotometric

Amorolfine (AOF) is a compound with fungicide activity based on the dual inhibition of growth of the fungal cell membrane, the biosynthesis and accumulation of sterols, and the reduction of ergosterol. In this work a sensitive kinetic and spectrophotometric method for the AOF quantitation based on the AOF oxidation by means of KMnO4at 30 min (fixed time), pH alkaline, and ionic strength controlled was developed. Measurements of changes in absorbance at 610 nm were used as criterion of the oxidation progress. In order to maximize the sensitivity, different experimental reaction parameters were carefully studied via factorial screening and optimized by multivariate method. The linearity, intraday, and interday assay precision and accuracy were determined. The absorbance-concentration plot corresponding to tap water spiked samples was rectilinear, over the range of 7.56 × 10−6–3.22 × 10−5 mol L−1, with detection and quantitation limits of 2.49 × 10−6 mol L−1and 7.56 × 10−6 mol L−1, respectively. The proposed method was successfully validated for the application of the determination of the drug in the spiked tap water samples and the percentage recoveries were 94.0–105.0%. The method is simple and does not require expensive instruments or complicated extraction steps of the reaction product.

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