Patent ID: 7427378

Claim:
An analysis apparatus for a sulfur component using ultraviolet fluorescence, which includes an introducing pipe for a sample gas; and an ultraviolet fluorometric analyzer, connected to the introducing pipe, and illuminating the sample gas with ultraviolet to detect fluorescence emitted accompanying the illumination and to thereby measure concentrations of sulfur components including at least SO 2 in the sample gas, the apparatus further comprising: means for oxidizing NO, which is an interferential component in the sample gas, to NO 2 installed part way downstream from an inlet end of the introducing pipe; a pretreatment section having a first gas line and a second gas line and a valve changing over between flows of the sample gas into the first and second gas lines provided downstream of the means for oxidizing NO and immediately prior to the ultraviolet fluorometric analyzer; and means for oxidizing a sulfur compound in the sample gas to SO 2 provided in the first gas line, wherein the second gas line provides any flow of sample gas to the ultraviolet fluorometric analyzer without oxidizing sulfur compounds to SO 2 .