Quantitative capillary techniques for photochemical experiments in the liquid phase

Abstract

A technique has been developed for simultaneous irradiation of 10 μl liquid samples in quartz capillaries for photochemical measurements. The method, in which the volatile samples once they are outgassed are kept from the atmosphere until analysis, is shown to be quantitative, with an accuracy to better than ±3% from sample to sample and batch to batch. A method for nonvolatile liquid samples is also described. Methyl propyl ketone has been used as a satisfactory chemical actinometer at 3130 Å in the capillary system. The quantum yield of formation of acetone from methyl-n-propyl ketone is 0123 and from methyl-n-amyl ketone is 0231 in the pure liquid at 25°C at 3130 Å.