THE COLORIMETRIC DETERMINATION OF PLATINUM WITH 5-(p-DIMETHYLAMINOBENZYLIDENE)-RHODANINE

1963 ◽  
Vol 41 (3) ◽  
pp. 667-670 ◽  
Author(s):  
Frances E. Piercy ◽  
D. E. Ryan
Keyword(s):  
Ascorbic Acid ◽  
The Other ◽  
Colorimetric Determination ◽  
Platinum Metals ◽  
Low Concentrations ◽  
Fold Excess

5-(p-Dimethylaminobenzylidene)-rhodanine is used to determine 0.5 to 6 p.p.m. of platinum colorimetrically, after reduction of platinum IV with ascorbic acid. Platinum can be determined in the presence of a 10-fold excess of palladium; low concentrations of the other platinum metals, except rhodium, do not seriously interfere.

Changes in Volatile Compounds during Ripening in Grapes of Airén, Macabeo and Chardonnay White Varieties Grown in La Mancha Region (Spain)

2003 ◽  
Vol 9 (1) ◽  
pp. 33-41 ◽  
Author(s):  
E. García ◽  
J. L. Chacón ◽  
J. Martínez ◽  
P. M. Izquierdo
Keyword(s):  
Volatile Compounds ◽  
Benzyl Alcohol ◽  
Volatile Compound ◽  
The Other ◽  
Optimum Level ◽  
Grape Variety ◽  
La Mancha ◽  
Low Concentrations

Changes in volatile compounds in musts and skins of grapes of Airén, Macabeo and Chardonnay white varieties were determined during ripening. The musts of the Airén variety contained higher concentrations of c-3-hexenol; musts of the Macabeo variety were the richest in t-3-hexenol and 2,4-hexadienal, while the Chardonnay musts stood out for having higher concentrations of benzaldehyde, phenylacetaldehyde and benzyl alcohol. The skins of the three varieties were both qualitatively and quantitatively richer in volatiles than were the musts. The skins of the Airén grapes had the highest levels of nerol. Airén grapes were the only variety in which citronellol was present in the skins. Low concentrations of eugenol were detected in the skins of the Chardonnay grape variety but were not present in the other two varieties. Changes in the concentration of the volatile compounds during ripening were not uniform; this made difficult the determination of the optimum level of ripening for each variety on the basis of the volatile compound content. Nevertheless, results indicated that C6 compounds and terpene concentrations reached a maximum at 6-8 ° Baumé in the Airén grapes and at around 11 ° Baumé in the Chardonnay and Macabeo grapes.

Colorimetric Determination of Low Concentrations of Oxygen in Gases

1955 ◽  
Vol 27 (12) ◽  
pp. 2012-2014 ◽  
Author(s):  
C. Stafford ◽  
J. E. Puckett ◽  
M. D. Grimes ◽  
B. J. Heinrich
Keyword(s):  
Colorimetric Determination ◽  
Low Concentrations

scholarly journals Potentiometric Determination of Chlorate Impurities in Hypochlorite Solutions

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Dmitry V. Girenko ◽  
Al’ona A. Gyrenko ◽  
Nikolai V. Nikolenko
Keyword(s):  
Sodium Hypochlorite ◽  
Sodium Sulfite ◽  
Systematic Errors ◽  
Expanded Uncertainty ◽  
Iodide Ions ◽  
Low Concentrations ◽  
Sophisticated Equipment ◽  
The Matrix ◽  
Fold Excess

The method of iodometric determination of chlorates impurities in sodium hypochlorite solutions for medical and veterinary purposes was developed. This method does not require sophisticated equipment and can be implemented directly where the solutions are used. The method is based on the different rates of interaction of ClO- and ClO3- with iodide ions depending on the acidity of the medium. We have shown that blank titration is advisable to improve the accuracy of the determination of low concentrations of chlorates in the matrix of hypochlorite which is present in excess since in this case possible systematic errors due to the presence of oxidizing impurities in the reagents are prevented. To quantify the low concentrations of chlorates, we proposed to remove 85-95% of hypochlorite ions by means of reducing their excess with sodium sulfite at pH 10.5. The solution of sodium sulfite does not require standardization before each analysis in the proposed procedure. The possibility of quantitative determination of chlorate impurities in the range of 2-50 mg/L in the presence of 50-500–fold excess of sodium hypochlorite with an error of 5% has been proved. The expanded uncertainty of chlorate determination did not exceed 0.6 mg/L.

Colorimetric Determination of Ascorbic Acid

1954 ◽  
Vol 26 (9) ◽  
pp. 1521-1522 ◽  
Author(s):  
Morton. Schmall ◽  
C. W. Pifer ◽  
E. G. Wollish ◽  
Robert. Duschinsky ◽  
Harold. Gainer
Keyword(s):  
Ascorbic Acid ◽  
Colorimetric Determination

THE SEPARATION OF SMALL AMOUNTS OF THE PLATINUM METALS: 1. THE COLORIMETRIC DETERMINATION OF RHODIUM AND ITS SEPARATION FROM IRIDIUM

1961 ◽  
Vol 39 (12) ◽  
pp. 2389-2393 ◽  
Author(s):  
D. E. Ryan
Keyword(s):  
Hydrochloric Acid ◽  
Stannous Chloride ◽  
Colorimetric Determination ◽  
Acid Solutions ◽  
Platinum Metals ◽  
Hydrochloric Acid Solutions ◽  
Product Separation ◽  
Chromous Chloride ◽  
Made In

A method for separating small amounts of rhodium from iridium is described. In 3 to 9 M hydrochloric acid solutions, the amber-to-red complex of bivalent rhodium with 4,5-dimethyl-2-mercaptothiazole is formed after reduction of tervalent rhodium with chromous or stannous chloride. Rhodium is quantitatively separated from iridium by chloroform extraction of this product; separation can be made in solutions that have been fumed with sulphuric acid if chromous chloride is used for the prior reduction of the rhodium. The complex, after removal of the chloroform, is dissolved in dilute hydrochloric acid, and the optical density of the resulting colored solution is measured.

Colorimetric determination of ascorbic acid

1973 ◽  
Vol 61 (6) ◽  
pp. 901-906 ◽  
Author(s):  
M. H. Hashmi ◽  
Maqbool Ahmad Shahid ◽  
M. Ahsan Akhtar ◽  
N. A. Chughtai
Keyword(s):  
Ascorbic Acid ◽  
Colorimetric Determination
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