Researches on the stability of porphyra-334 solution and its influence factors

The stability of porphyra-334 in solutions of different pH values at different temperatures was studied. In high acidic conditions, below pH3, the absorption maximum, λ_max, of porphyra-334 shows hypsochromic shift towards lower wavelength and the absorbance also has a light decrease. In high alkaline conditions of over pH12, the absorbance of porphyra-334 decreases and an unknown compound with a peak maximum at 225 nm appears. The peak height of the unknown compound increases with the decrease of absorbance of porphyra-334. This might be related to the decomposition of porphyra-334. At room temperature, porphyra-334 solutions, except high alkaline solutions, are stable. Increasing the temperature, especially higher than 60°C, promotes the decomposition of porphyra-334 and causes the absorbance decrease both in basic and acidic solutions.