scholarly journals Critical Comparison between Modified Monier-Williams and Electrochemical Methods to Determine Sulfite in Aqueous Solutions

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
C. Montes ◽  
J. H. Vélez ◽  
G. Ramírez ◽  
M. Isaacs ◽  
R. Arce ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Differential Pulse Voltammetry ◽  
Gallic Acid ◽  
Standard Addition ◽  
Differential Pulse ◽  
Standard Addition Method ◽  
Correction Coefficient ◽  
Addition Method ◽  
Critical Comparison ◽  
Pulse Voltammetry

In the present work, known concentration of sulfite aqueous solutions in the presence and absence of gallic acid was measured to corroborate the validity of modified Monier-Williams method. Free and bound-sulfite was estimated by differential pulse voltammetry. To our surprise, the modified Monier-Williams method (also known as aspiration method) showed to be very inaccurate for free-sulfite, although suitable for bound-sulfite determination. The differential pulse approach, using the standard addition method and a correction coefficient, proved to be swift, cheap, and very precise and accurate.

Use Differential Pulse Voltammetry for Determining the 2,6-Ditertbutyl-4-Methylphenol in Jet Fuels

2012 ◽  
Vol 455-456 ◽  
pp. 716-720 ◽  
Author(s):  
Yong Gang Shi ◽  
Bin Su ◽  
Hai Feng Gong ◽  
Yan Xue
Keyword(s):  
Differential Pulse Voltammetry ◽  
Standard Addition ◽  
Differential Pulse ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Addition Method ◽  
Electrolytic Solution ◽  
Voltammetric Characteristics ◽  
Pulse Voltammetry

A new method for determination of antioxidants in jet fuels, which is based on the differential pulse voltammetric characteristics of the antioxidant 2,6-ditertbutyl-4-methylphenol in the solution of saturated KOH anhydrous ethyl alcohols, is established. The experimental results have shown that there is a linear relationship between the content of 2,6-ditertbutyl-4-Methyl-phenol in the jet fuel and the differential pulse voltammetry response in the electrolytic solution. It has also been shown that the antioxidant contents can be reliably and simply determined with the help of the standard addition method. The largest relative error of the determination is 6.70 %, the biggest confidence for 5 samples is 1.95 mg/L (n=5, 95% confidence level).

XRF Analysis by Combining the Standard Addition Method with Matrix-Correction Models

1982 ◽  
Vol 26 ◽  
pp. 395-400
Author(s):  
Peter B. De Groot
Keyword(s):  
Linear Regression Analysis ◽  
Standard Addition ◽  
Standard Addition Method ◽  
Correction Coefficient ◽  
Matrix Correction ◽  
Addition Method ◽  
Low Concentrations ◽  
Wide Range ◽  
Before And After ◽  
Single Standard

AbstractThe standard addition method is often useful for singleelement analyses in matrices of unknown composition or those difficult to reproduce. Results are good at low concentrations where concentration vs. intensity is approximately linear, but serious errors occur at higher concentrations. A method is shown here for greatly extending the range of the standard addition approach by combining it with with matrix correction models. Expressions incorporating the well-known alpha-or beta-correction coefficients are derived for the observed intensities before and after addition of the analyte. K-ratio measurements on the saraple plus a single standard addition allow the calculation of the correction coefficient and analyte concentration. Several standard addition levels can also be used and concentration obtained from non-linear regression analysis. A computer program has been developed to perform these calculations. Analyses of CuO on silica and of four metals in a metal oxide catalyst over a wide range of concentrations gave results with a relative accuracy generally within ±5%.

scholarly journals Net analyte signal standard addition method for the simultaneous determination of cadmium and nickel

2009 ◽  
Vol 74 (7) ◽  
pp. 789-799 ◽  
Author(s):  
Karim Asadpour-Zeynali ◽  
Reza Majidi ◽  
Masoud Tahmasebpour
Keyword(s):  
Simultaneous Determination ◽  
Standard Addition ◽  
Differential Pulse ◽  
Single Step ◽  
Standard Addition Method ◽  
Differential Pulse Polarography ◽  
Addition Method ◽  
Net Analyte Signal ◽  
Analyte Signal

A novel net analyte signal standard addition method (NASSAM) is presented for the simultaneous determination of Cd2+ and Ni2+ in their mixture by differential pulse polarography. The method combines the advantages of the standard addition method with the net analyte signal concept, which enables the extraction of information concerning a certain analyte from voltammograms of multi-component mixtures. This method has some advantages, such as: the use of a full voltammogram, realization in a single step, therefore it does not require calibration and prediction steps and only a few measurements are required for the determination. The simultaneous determination of Cd2+ and Ni2+ was performed in Britton-Robinson buffer (pH 2.87) and 0.40 M potassium thiocyanate solution.

Investigations On The Binding Of Mercury Ions To Albumins Employing Differential Pulse Voltammetry

2003 ◽  
Vol 10 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Clarissa Pires de Castro ◽  
Jurandir SouzaDe ◽  
Carlos Bloch Jr
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Mercury Ions ◽  
Pulse Voltammetry

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The voltammetric determination of 4-nitrobiphenyl

1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Working Electrode ◽  
Pulse Voltammetry ◽  
Unstirred Solution

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

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