A Gas Chromatographic Method for the Determination of Oxygen Dissolved in Water Using an Electron Capture Detector

Abstract

A rapid and accurate method for the routine determination of oxygen dissolved in water is described. A small sample (10 μl) is injected onto a column packed with Porapak T, which retains the water. Subsequently, oxygen is separated from other gases on a column packed with Molecular Sieve 5A and then detected with an electron capture detector. The use of two columns of Porapak T fitted to a backflush valve permits venting of the retained water vapour from one, while a subsequent sample is being analysed on the other. An analysis takes one minute and the coefficient of variation for the oxygen contained in water saturated with the ambient atmosphere is 0.33%.