THE POLAROGRAPHY OF THE MAGNESIUM-ALIZARIN SYSTEM

1963 ◽  
Vol 41 (7) ◽  
pp. 1695-1702 ◽  
Author(s):  
D. G. Brewer ◽  
John A. Page
Keyword(s):  
Aqueous Solution ◽  
Diffusion Coefficient ◽  
Ammonium Chloride ◽  
Polarographic Determination ◽  
Reduction Wave ◽  
Soluble Complex ◽  
Reversible Process ◽  
Complex Species ◽  
Polarographic Wave

The polarography of alizarin alone, and alizarin in the presence of magnesium, has been studied in an ammonia–ammonium chloride electrolyte. Alizarin was found to give a reduction wave with E1/2 = −(0.14 + 0.059 pH) volts vs. S.C.E. and a polarographic diffusion coefficient D, equal to 1.20 × 10−6 cm2 sec−1 over a range of pH from 7.4 to 10.0 in aqueous solution at 25 °C. The slope of the wave corresponded to a two-electron reversible process. The addition of magnesium caused a decrease in the polarographic wave for alizarin, but the combining ratio of magnesium to alizarin was a function of pH, ranging from 1.02 at pH 9.0 to 1.28 at pH 10.1. The combining ratio greater than unity could be attributed to alizarin adsorbed on a 1:1 (MgAlz) precipitate. The removal of alizarin from the solution was not quantitative in the presence of excess magnesium, and there is evidence of the formation of soluble complex species. The reaction is potentially useful for the indirect polarographic determination of magnesium.

Effect of pH and phosphate ions on the polarographic behavior of D-glucuronolactone

1969 ◽  
Vol 47 (2) ◽  
pp. 265-272 ◽  
Author(s):  
R. J. Thibert ◽  
J. R. Johnston
Keyword(s):  
Aqueous Solution ◽  
Glucuronic Acid ◽  
Polarographic Determination ◽  
Polarographic Behavior ◽  
Effect Of Ph ◽  
Polarographic Wave ◽  
Phosphate Ions ◽  
Trialkyl Phosphites

The polarographic determination of D-glucuronolactone in aqueous solution was shown to be feasible up to a concentration of 6 mg per ml in KCl, NaCl, and LiCl with gelatin as the maximum suppressor. The effect of pH and phosphate ions on the polarographic wave of D-glucuronolactone is discussed and compared to the reaction of dialkyl hydrogen phosphites and trialkyl phosphites with β-propiolactones. The effect of pH and phosphate ions on the polarographic wave of D-glucuronic acid was also investigated.

Split-flow Taylor dispersion technique for diffusivity and concentration measurements of hydrazine in aqueous solution

2014 ◽  
Vol 92 (4) ◽  
pp. 279-283
Author(s):  
Kashif I. Choudhry ◽  
Igor M. Svishchev ◽  
Andriy Plugatyr
Keyword(s):  
Aqueous Solution ◽  
Diffusion Coefficient ◽  
Taylor Dispersion ◽  
Alkaline Media ◽  
Monitoring Method ◽  
Flow Monitoring ◽  
Split Flow ◽  
Taylor Dispersion Technique ◽  
Dispersion Technique

A sensitive continuous-flow monitoring method is developed for the determination of the diffusion coefficient and concentration of hydrazine in an aqueous solution. The effect of pH on the diffusion coefficient of hydrazine in water was studied at room temperature using the developed split-flow Taylor dispersion technique. The hydrazine calibration curve was linear in the range of 10−1000 ppb and the limit of quantification was 10 ppb. The results showed that the diffusion coefficient of hydrazine does not change significantly over the pH range of 4.01−8.27 but increases in alkaline media of pH greater than 8.27. This method can be used for accurate determination of hydrazine concentration in aqueous flow systems.

scholarly journals Determination of the Diffusion Coefficient of the Green and Violet Isomers of Cr2(SO4)3 in Aqueous Solution

1994 ◽  
Vol 35 (12) ◽  
pp. 902-909 ◽  
Author(s):  
Karen S. Yoshiki-Gravelsins ◽  
Tetsuji Hirato ◽  
Yasuhiro Awakura ◽  
Hiroshi Majima
Keyword(s):  
Aqueous Solution ◽  
Diffusion Coefficient

The Polarographic Determination of Selenium in Urine

1961 ◽  
Vol 7 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Albert G Faulkner ◽  
Edward C Knoblock ◽  
William C Purdy
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Potassium Chloride ◽  
Ammonium Chloride ◽  
Polarographic Determination ◽  
Average Error ◽  
Diffusion Controlled ◽  
Sample Stability

Abstract Polarographic data are presented for the reduction of selenite ion in 3M sulfuric acid, 1M potassium chloride, and 1M ammonia-ammonium chloride. In these first two media two waves are obtained corresponding to the diffusion-controlled reduction of selenite ion to selenium amalgam and the adsorption of selenite ion on the mercury drop, respectively. One wave is obtained in ammonia-ammonium chloride corresponding to the reduction of selenite to selenide ion. Selenium has been determined in urine over a concentration range of 0.0063 to 0.175 mM. (0.5 to 14 µg./ml., in a 10-ml. sample) with an average error of 2 percent. The effects of the time and method of storage on the loss of selenium by urine have been investigated. Although selenium is lost by urine under all methods investigated, storage in a deep freeze results in greater sample stability. It was also found that this loss could be prevented if the urine was made 1 molar to nitric acid.

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