An Ultrasensitive Photoacoustic Spectrophotometer for Liquids

Abstract

The radius of a cylindrical photoacoustic cell for liquids and the phase of the amplification system were optimized, based on the theory of photoacoustic signal detection. As a result of the optimization, the minimum detectable absorption coefficient, calculated from calibra tion curves obtained for cobalt 1-nitroso-2-naphthol chelate xylene solutions was 8.7×10-6cm-1 and the detection limit absorption coefficient of this photoacoustic spectrophotometer, expressed in twice the signal to noise ratio, was 3.8×10-8 cm-1.