Indirect determination of ethanol in drinks using a capacitance flow-through detector

A flow procedure based on a metallic capacitance flow-through detector is d escribed for the analysis of water vapour. The capacitance detector consist s of two stainless steel tubes and is located in the loop of a sampling val ve. The logarithm of the capacitance signal correlates linearly with the co ncentrations of water vapour in the 1705 to 2197 Pa range. A sampling frequ ency of about 55 h can be achieved. The flow system was applied to the indi rect determination of the ethanol concentration in drinks based on the anal ysis of water vapour content above the liquid sample, without any pre-treat ment of the sample. The colour of the drinks has no effect on the measureme nts.