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 %.

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.

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 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 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.

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.

Preparation of Adsorbents Based on Dendrimer Modified Silica Gel and its Adsorption Performances for Lead

2013 ◽  
Vol 800 ◽  
pp. 166-172
Author(s):  
Xiong Zhi Wu ◽  
Li Li ◽  
Fei Ping Li ◽  
Wen Ying Jin
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Silica Gel ◽  
Limit Of Detection ◽  
Modified Silica ◽  
Modified Silica Gel ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration

A new sorbent (PAMAM4.0GASG) with gallic acid as functional group has been prepared based on G4.0 polyamidoamine dendrimer modified silica gel (PAMAM4.0SG) and characterized with FTIR. It was employed for selective separation, preconcentration and determination of lead in different samples by flame atomic absorption spectrometry (FAAS). Experimental conditions for effective separation and preconcentration of lead were optimized. The preconcentration factor reaches 200 for lead. The relative standard deviation (R.S.D.) under optimum conditions was 2.1% for 5.0 μg ml1 of Pb (II).The relative standard deviation (R.S.D.) was 2.1% for 5.0 μg ml1 of Pb (II). The limit of detection (LOD) of 0.081μg ml1 was achieved with a sample loading flow rate of 4.2 ml min1 and a 10 ml sample volume in the proposed method. The proposed column enrichment method was applied for the preconcentration/separation and determination of Pb (II) in tap water and river water samples successfully.

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.

Cloud Point Extraction-Fluorimetric Combined Methodology for the Determination of Magnolol

2013 ◽  
Vol 699 ◽  
pp. 34-39
Author(s):  
Li Liu ◽  
Xia Shi Zhu
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Cloud Point ◽  
Relative Standard Deviation ◽  
Cloud Point Extraction ◽  
Calibration Graph ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Triton X

A new Triton X-114 cloud point extraction combined with fluorometry method for analysis of magnolol in drug samples was developed. Under the optimum conditions, the calibration graph was linear in the range of 2.0-150.0ng/mL of magnolol in the initial solution with r = 0.9998. Detection limit (DL) was 0.03ng/mL (S/N=3) and the relative standard deviation (RSD) for 20.0ng/mL of magnolol was 2.79%(n=11). The method was successfully applied for the determination of magnolol in drug samples with satisfactory results.

Determination of diltiazem based on the reduction of Cu(II)–BCA complexes in micellar medium

2010 ◽  
Vol 88 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Larissa Zuppardo Lacerda Sabino ◽  
Daniele Cestari Marino ◽  
Horacio Dorigan Moya
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Confidence Level ◽  
Limit Of Detection ◽  
Calibration Graph ◽  
Micellar Medium ◽  
Solution Ph ◽  
Simple Method ◽  
Relative Standard

A simple method was developed for determining microquantities of diltiazem, based on the reduction of copper(II) in buffered solution (pH 7.0) and the use of a micellar medium containing 4,4′-dicarboxy-2,2′-biquinoline acid. The copper(I) produced reacts with 4,4′-dicarboxy-2,2′-biquinoline acid and the complexes formed are spectrophotometrically measured at 558 nm. A typical calibration graph shows good linearity (r = 0.993) from 20 to 100 μg mL–1 of diltiazem. The limit of detection and relative standard deviation were calculated as 12 μg mL–1 (99% confidence level) and 3.5% (40 μg mL–1; n = 6), respectively, with a mean recovery value of 96.5% found in pharmaceutical dosages. A straightforward and effective way to recycle the reagents is addressed. The hazardous aspects of the Cu(I)–BCA reaction are presented as well.

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