Assay for alkali salts of organic acids**Read before the Kings County Pharmaceutical Society, March 8, 1932.

Proflavine binding of a sensitive strain of Bacillus subtilis and of a resistant strain derived from it was compared. Proflavine was bound very rapidly and more was bound at 0 °C than at 37 °C. Boiling increased the proflavine-binding capacity at 37 °C of sensitive but not of resistant cells. The binding capacity of sensitive and resistant cells suspended in buffer was the same; this was also true in various growth media. If cells were able to grow in the presence of proflavine their proflavine content decreased.Bound proflavine was released when cells were treated with growth media or with the salts of growth media. Sodium salts of organic acids also caused a release. This effect seemed due to their Na+ content, and was somewhat higher for resistant than for sensitive cells. The mechanism of proflavine resistance in B. subtilis is probably different from that of Escherichia coli, which is thought to depend on an energy-driven release of bound proflavine.

Download Full-text

Reviews-Electrolysis of the alkali salts or organic acids

The Journal of Physical Chemistry ◽

10.1021/j150028a659 ◽

1901 ◽

Vol 5 (1) ◽

pp. 85-85

Author(s):

J. Petersen

Keyword(s):

Organic Acids ◽

Alkali Salts

Download Full-text

Effect of Metallic Poisons. Especially Manganese, on Aging of Vulcanized Natural Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3543309 ◽

1947 ◽

Vol 20 (3) ◽

pp. 821-826

Keyword(s):

Organic Acids ◽

Natural Rubber ◽

Harmful Effect ◽

Manganese Compound ◽

Naturally Occurring ◽

Different Types ◽

Salts Of Organic Acids ◽

General Experience ◽

Manganese Compounds ◽

Harmful Effects

Abstract 1. Information received from rubber manufacturers on their experience of the effects of manganese and copper on aging is summarized. Although there is evidence that the amounts of these impurities in fillers tended to increase during the early war years (1939–42), it seems to be the general experience that little trouble arose from their effects on the properties of the rubber. Fillers containing as much as 0.05–0.10 per cent of manganese, or 0.005 per cent of copper, have not shown any obvious harmful effects. 2. Experiments with a large number of manganese compounds, including naturally occurring (mineral) forms and salts of organic acids, used in amounts equivalent to 0.01 per cent manganese on the raw rubber, have failed to show any pronounced harmful effect on the aging (oven or oxygen bomb) of a vulcanized natural rubber containing mercaptobenzothiazole, although deterioration was noticeably accelerated in some cases. Probably on account of the smallness of the effects observed, it is not possible as yet to draw any conclusion as to the relative activities of different types of manganese compound. 3. According to results of previous workers, manganese in the amount used in the present experiments can produce a more serious effect than these experiments indicate. The effect of manganese is known to depend on the type of mix used, and this aspect of the problem would thus appear to merit further investigation, as does also the influence of the method and degree of dispersion of the manganese compound in the rubber mix.

Download Full-text