Accelerated Degradation Experiment
Conditions
Procedure A: |
30 days exposure at 50 °C and 100% relative humidity. |
Procedure B: |
30 days exposure at 50 °C and 100% relative humidity followed by 5 days at 70 °C and 100% relative humidity. |
Appearance of the material
The material, originally in the form of green-yellowish to green-brownish, thin and brittle leaflets changes after procedures A and B into flexible leaflets, dark brown in colour and spotted with mould.
Gain of moisture:
Before exposure to head and humidity: |
about 7% |
After procedures A and B: |
50%. |
Chromatographic test
Adsorbent: Silica gel 60 F-254
Solution applied to the plate: Solution of the material obtained after extraction with hot ethane 50%.
Solvent system:
water.................... 3 volumes
ethyl acetate......... 4 volumes
1-propanol........... 4 volumes
Development condition: The solvent is allowed to migrate until the front reaches a line 15 cm from the starting line.
Detection: The plate is examined under ultraviolet light at a wavelength of maximum output at about 254 nm and then at 365 nm. After spraying the plate with a 20% solution of nitric acid, heating at 110-120 °C, cooling and again spraying with a 5% solution of potassium hydroxide in ethane 50%, it is examined in daylight.
Results: The reference solution of senna leaf shows numerous spots of different intensities. Important changes are observed after procedures A and B, some spots disappear and new ones occur.
Gas-liquid chromatography
After procedures A and B, the chromatograms show significant changes in the intensities of the major peaks and the disappearance of some of them.
Conclusion
Senna leaf is subject to decomposition under accelerated degradation conditions.
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