Pyridoxal-5-Phosphate purity

Finally in the purity of reagent grade chemicals field there have been surprisingly few polarographic methods described. Thus in a preparation of 5,8-dihydrox)maphthoquinone about 20 per cent of the labelled substance< ) was found, and in a preparation of erythrose less than 5 per cent of the substance. In pyridoxal-5-phosphate preparation about 1-5 per cent of pyridoxal could be detected. These are only a few examples of compounds produced by well-known companies. It is doubtless that the specific properties of polarographic analysis would make the method very suitable as a control technique in this field. 

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