[A spectrophotometric method for controlling the concentration of aromatic hydrocarbons in the calibration of indicator tubes].

A modified spectrophotometric method is proposed for monitoring air concentrations of xylol, toluol, benzol, ethylbenzol, and chlorobenzol. The method has been introduced to control concentrations of the above aromatic hydrocarbons in calibrating indicator tubes, manufactured by the firm "Hygitest", and complies to the specific requirements for that process. There are possible applications in other areas, but further studies would be needed. The proposed method satisfies accuracy and reproducibility requirements. It successfully replaces the more laborious gas chromatographic and IR spectroscopic methods.