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 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.

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.

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 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 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.

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.

A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone

2014 ◽  
Vol 70 (7) ◽  
pp. 1182-1187 ◽  
Author(s):  
Zhe Chen ◽  
Hua Li
Keyword(s):  
Flow Injection ◽  
Water Samples ◽  
High Sensitivity ◽  
Basic Solution ◽  
Optimum Conditions ◽  
Cetylpyridinium Bromide ◽  
Test Conditions ◽  
Relative Standard

Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3–40 μg L−1 with a detection limit of 0.1 μg L−1 at about 60 h−1 sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L−1 Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt 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.

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