scholarly journals Catalytic Spectrophotometric Method for Determination of Formaldehyde Based on its Catalytic Effect on the ReactionBetween Bromate and Safranin

2010 ◽  
Vol 7 (s1) ◽  
pp. S481-S487
Author(s):  
Mohsen Keyvanfard
Keyword(s):  
Sulfuric Acid ◽  
Standard Deviation ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Kinetic Method ◽  
Fixed Time ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Replicate Measurements

The reaction monitored spectrophotometrically by measuring the decrease in absorbance of the reaction mixture at 533 nm. The fixed-time method was used for the first 60s. For initiation of the reaction, under the optimum conditions, in the concentration range of 0.02-1.5 μg mL–1formaldehyde can be determined with a limit of detection 9.5 ng mL–1. The relative standard deviation of five replicate measurements is 2.3% for 0.5 μg mL–1of formaldehyde. The method was used for the determination of formaldehyde in water samples with satisfactory results. A new simple and fast catalytic kinetic method for the determination of trace amount of formaldehyde is described. The method is based on the catalytic effect of formaldehyde on the oxidation of safranin by bromate in the present of sulfuric acid.

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.

Study on the Kinetic Spectrophotometric Determination of Selenium (IV) on Oxidation of Neutral Red with Potassium Periodate and its Application

2012 ◽  
Vol 610-613 ◽  
pp. 446-451
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Neutral Red ◽  
Optimum Conditions ◽  
Hair Samples ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

Based on the oxidation of neutral red by KIO4 in 3.2×10-4 mol/L sulfuric acid solution, a simple kinetic spectrophotometric method was developed for the determination of trace amounts of Se(IV).The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of neutral red at 530 nm with a fixed-time method. The decrease in the absorbance of neutral red is proportional to the concentration of Se(IV) in the range 0.0–8.0 µg/L with a fixed time of 4–6 min from the initiation of the reaction. The limit of detection is 0.36 µg/L Se(IV). The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 81.60 kJ/mol. The relative standard deviation for the determination of 0.1 and 0.2 µg/mL Se(IV) was 2.1 and 1.9 %, respectively. The method has been successfully applied to the determination of Se (IV) in tea and human hair samples with the relative standard deviation of 0.33 %–1.5 % and the recovery of 97.5 %–103.5 %.

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 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 Kinetic Spectrophotometric Determination of Gemifloxacin Mesylate and Moxifloxacin Hydrochloride in Pharmaceutical Preparations Using 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammed G. Abdel Wahed ◽  
Ragaa El Sheikh ◽  
Ayman A. Gouda ◽  
Sayed Abou Taleb
Keyword(s):  
Limit Of Detection ◽  
Kinetic Method ◽  
Pharmaceutical Preparations ◽  
Fixed Time ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results

Simple, sensitive, and accurate kinetic spectrophotometric method was proposed for the determination of gemifloxacin mesylate (GMF) and moxifloxacin hydrochloride (MOX) in pure forms and pharmaceutical preparations (tablets). The method is based on coupling the studied drugs with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in the presence of alkaline borate buffer. Spectrophotometric measurement was achieved by recording the absorbance at 466 and 464 nm for GMF and MOX, respectively, after a fixed time of 20 and 15 min on a water bath adjusted at 70 ± 5°C for both drugs. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The absorbance-concentration plots were linear over the ranges 0.5–8.0 and 2.0–12 μg mL−1for GMF and MOX, respectively. The limit of detection of the kinetic method was about 0.12 (2.47 × 10−7 M) and 0.36 (8.22 × 10−7 M) μg mL−1for GMF and MOX, respectively. The proposed methods have been applied and validated successfully with percentage relative standard deviation (RSD% ≤ 0.52) as precision and percentage relative error (RE% ≤ 1.33) as accuracy. The robustness of the proposed method was examined with recovery values that were 97.5–100.5 ± 1.3–1.9%. Statistical comparison of the results with the reference spectrophotometric methods shows excellent agreement and indicates no significant difference in accuracy or precision.

Spctrophotometric Determination of Trace Ruthenium by its Catalytic Effect on Oxidation of 3,5-DiBr-PADAP with KIO4

2012 ◽  
Vol 554-556 ◽  
pp. 1999-2005
Author(s):  
Zhi Rong Zhou ◽  
Qun Wang ◽  
Shu Yuan Zhang
Keyword(s):  
Activation Energy ◽  
Standard Deviation ◽  
Detection Limit ◽  
Catalytic Reaction ◽  
Oxidation Reaction ◽  
Catalytic Effect ◽  
Optimum Conditions ◽  
Potassium Periodate ◽  
Relative Standard

A spectrophotometric method for the determination of ruthenium (III) is described, based on its catalytic effect on the oxidation reaction of 2-[(3,5-dibromo-2-pyridy)azo]-5-diethylaminophenol (3,5-diBr-PADAP) with potassium periodate in 0.008 mol/L sodium hydroxide medium and in the presence of OP emulsifier (p-iso-octyl phenoxy polyethoxy ethanol) at 100 °C. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 530 nm for the catalytic reaction of 3,5-diBr-PADAP. The calibration curve for the recommended method was linear in the concentration range over 0.04 µg/L–1.0 µg/L and the detection limit of the method for Ru (III) is 0.012 µg/L. The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 100.48 kJ/mol. The relative standard deviation for the determination of ruthenium (III) at the concentration of 0.02 µg/25mL is calculated to be 2.30 % (n=11). In combination with distilled separation, the method has been successfully applied for the determination of trace ruthenium (III) in some ores and metallurgy products with the relative standard deviations (RSD) over 1.8 %–2.9 % and the recovery over 98.1 %–103.1 %.

Kinetic Spectrophotometric Determination of Selenium (IV) by its Catalytic Effect on the Oxidation of Acid Chrome Blue K by Hydrogen Peroxide

2012 ◽  
Vol 538-541 ◽  
pp. 2358-2363 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Acid Chrome Blue K ◽  
Good Agreement

Based on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid solution, while 1,10-phenanthroline (phen) acts as an activator, a simple kinetic spectrophotometric method was developed for the determination of trace amounts of Se(IV).The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of ACBK at 524 nm with a fixed-time method. The decrease in the absorbance of ACBK is proportional to the concentration of Se (IV) in the range 0.06–1.0 µg/L with a fixed time of 4–10 min from the initiation of the reaction. The limit of detection is 0.018 µg/L Se (IV). The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 62.30 kJ/mol. The relative standard deviation for 11 replicate determination of 0.01 and 0.02 µg/25mL selenium (III) was calculated to be 2.3 % and 2.0 %, respectively. Combined with sulphydryl dextrane gel (SDG) separation and enriching, the method has been successfully applied to the determination of Se (IV) in foodstuff samples with the relative standard deviation of 1.1 %–3.7 % and the recovery of 99.0 %–104.0 %, the results are in good agreement with those provided by HG-AAS 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 %.

Spectrophotometric Determination of Trace Ruthenium by its Catalytic Effect on Oxidation of Switzerland Pigment with KIO4

2013 ◽  
Vol 781-784 ◽  
pp. 93-98
Author(s):  
Su Ping Chen ◽  
Zhi Rong Zhou ◽  
Cheng Jie Cai ◽  
Yan Ling Fang ◽  
Zhi Cheng Fu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Standard Deviation ◽  
Catalytic Reaction ◽  
Oxidation Reaction ◽  
Catalytic Effect ◽  
Optimum Conditions ◽  
Potassium Periodate ◽  
Chloride Medium ◽  
Relative Standard

A spectrophotometric method for the determination of ruthenium (III) is described, based on its catalytic effect on the oxidation reaction of switerland pigment with potassium periodate in 0.016 mol/L of hydrogen chloride medium and in the presence of OP emulsifier (p-iso-octyl phenoxy polyethoxy ethanol) at 100 °C. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 608 nm for the catalytic reaction of switerland pigment. The calibration curve for the recommended method was linear in the concentration range over 0.041.0 μg/L and the detection limit of the method for Ru (III) is 0.012 μg/L. The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 100.48 kJ/mol. The relative standard deviation for the determination of ruthenium (III) at the concentration of 0.02 μg/25 mL is calculated to be 2.3 % (n=11). In combination with distilled separation, the method has been successfully applied for the determination of trace ruthenium (III) in some ores and metallurgy proucts with the relative standard deviations (RSD) over 2.9 %3.8 % and the recovery over 98.2 %-103.6 %.

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