Patent ID: 7244395

Claim:
An apparatus for performing low level sulfur UV fluorescence detection comprising: an oxidation or combustion chamber including: a sample inlet, an oxidizing agent inlet, an oxidation zone, and an oxidized sample outlet, where the oxidation chamber is adapted to convert substantially all oxidizable components of a sample into their corresponding oxides; a transfer tube connected to the oxidized sample outlet adapted to transfer the corresponding oxides to an UV chamber; an UV interference reduction system adapted to introduce an UV interference reduction agent into the sample before during and/or after oxidation, where the UV interference reduction agent is capable of reducing or eliminating nitrogen oxides that interfere with sulfur UV fluorescence detection; and a detector/analyzer system including: an excitation light source adapted to generate excitation light, the UV chamber having: an excitation light port in optical communication with the light source adapted to excite SO 2 molecules in the oxidized sample into electronically excited SO 2 molecules, an oxidized sample inlet connected to the transfer tube, an oxidized sample outlet for exhausting the oxidized sample from the chamber after irradiation from the excitation light, and a fluorescent light port oriented at an angle to the excitation light port, where the angle is sufficient to reduce or eliminate excitation light from entering the fluorescent light port; a fluorescent light detector in optical communication with the fluorescent light port adapted to detect fluorescent light emitted by the electronically excited SO 2 molecules passing through the fluorescent light port and to convert the detected fluorescent light into an electrical output signal, and an analyzer in electrical communication with the detector and adapted to convert the electrical output signal into a concentration of sulfur in the sample, where the UV interference reduction agent is introduced in an amount sufficient to convert interfering nitrogen oxides into non-interfering nitrogen oxides thereby lowering a sulfur detection limit to sulfur concentrations of less than 100 ppb.