New spectrophotometric method for the determination of phenolic hormones

A new simple, selective and accurate spectrophotometric method is described for the determination of mono- and dihydric phenolic hormones (oestrogens and catecholamines) by nitration at 50 degrees and 100 degrees , respectively, for 10 min, followed by treatment with alkali. Coloured products with absorption maxima at 430, 385, 430, 380 and 380 nm, linearly proportional to the concentration of oestrone, oestradiol, ethinyloestradiol, adrenaline and noradrenaline, respectively, are obtained. Information is presented on the effect of nitration time, temperature, solvents, and alkali concentration. The method is satisfactorily applied to the determination of these hormones in the range 10-50mug ml in the final solution, of volume 10ml. The relative standard deviation is +/- 0.5% and no interferences are caused by non-phenolic hormones.