Temperature coefficient of chlorophyll decomposition in the light
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Temperature coefficient of chlorophyll decomposition in the light.
L. A. Ivanov. On the influence of temperature on the decomposition of chlorophyll by light. Journal of the Russian Botanical Society, vol. 4, p. 11, 1920.
The author measured the dependence of the initial rate of decomposition of ether and scindapsus extracts of chlorophyll from fresh leaves of Aspidistra on temperature. The temperature interval was \(5^\circ\)—\(40^\circ\); the light source was a 3000-candlepower “Nitro” lamp. The amount of decomposed chlorophyll was measured spectrophotometrically. Part of the experiments was carried out with collodion films stained with chlorophyll and applied to glass. The results are given in the table.
TABLE I.
| Medium | Temperature coefficient |
|---|---|
| Turpentine | 1.040 |
| Alcohol | 1.065 |
| Collodion film | 1.004 |
In addition, by measuring the temperature coefficient of chlorophyll decomposition when applied to photographic paper, and after illumination washing the chlorophyll off the paper with alcohol and subjecting the colored solution obtained to electrophotometry. The temperature coefficient found in this way was 1.285. The indicated method of washing off the chlorophyll gives a figure that is somewhat too low. More accurate results could be obtained by electrophotometrizing the paper in reflected light. On the basis of the figures obtained, the author concludes that the solvent medium has a considerable influence on the temperature coefficient of the photochemical decomposition of chlorophyll.
C. Vasil’ev.