Abstract: Our system for determining the sulfur content of a sample includes combusting the sample to form a gas in which the sulfur is converted primarily to sulfur dioxide in known ratio with the sulfur trioxide. The gas sample is passed into a reaction vessel containing a substantially pyridine solvent. The sulfur dioxide is scrubbed from the sample (trapping) via a binding action with the pyridine. The bound sulfur dioxide is titrated with elemental iodine in the presence of alcohol and excess water. The trapping and titration sequence can be simultaneous and continuous. A polarized electrode pair is preferably employed as the detection means with the end point determination occurring when the electrodes become current conducting in the presence of excess iodine. The titrant volume is then converted to a sulfur analysis by standard means. The apparatus is disclosed for carrying out the method.