An electrochemical sulfur detector has been developed to measure low ppb levels of different sulfur compounds in beverage grade CO2 and bulk gases such as Nitrogen. This electrochemical sulfur detector can selectively measure sulfur compounds since a gas chromatographic column is used to speciate the compounds before the sample is introduced into the detector. A reactor after the GC column converts all sulfur compounds in the sample to the electrochemically active species H2S. This allows the detection of electrochemically inactive sulfur compounds such as carbonyl sulfide, and further, provides equimolar sulfur response. Electrochemical sulfur detectection is both less expensive, and easier to use and maintain, compared to detection via sulfur chemiluminescence. The electrochemical sulfur detector has excellent detection limits (10 ppb sulfur) and high selectivity (more than a million-fold larger response to sulfur compounds compared on an equimolar ratio to carbon dioxide). The sulfur response is equimolar and linear over at least three orders of magnitude, and therefore only single-point calibration is required. The detector demonstrates excellent long term stability of better than 2 % RSD over 24 hrs.