Serum levels of 8-methoxypsoralen in psoriasis patients using a new fluorodensitometric method.

A method is described for the determination of 8-methoxypsoralen in human serum using a fluorodensitometric method. The fluorescence densitometry was carried out directly on the thin layer plate. The developing fluid consisted of chloroform/methanol. In patients with psoriasis after oral application of 8-methoxypsoralen the peak serum levels are mostly found between 2 and 3 h. One milliliter serum is sufficient to determine 8-methoxypsoralen levels. The results are in accordance with those obtained with gas chromatographic methods.