Abstract: A method and apparatus are disclosed for the improving the sensitivity of fluorescent detectors, especially UV fluorescent detectors using a light reaction cell including a reaction chamber having an optically smooth, highly reflective interior surface. The chamber can also include an insert that imparts either or both optically smooth and high reflectivity to the chamber. Increased interior surface smoothness and reflectivity significantly improves sensitivity and detection limits making ppb measurements routine.

Abstract: A more efficient combustion or oxidation device for the formation of nitrogen, phosphorus and/or sulfur oxides from a sample containing these elemental constituents is disclosed. The device uses multi-staged addition of an oxidizing agent to enhance oxidation and liberation of nitrogen, phosphorus and/or sulfur oxides for subsequent detection. The oxidation devices of the present invention allow for the injection of larger samples or, the introduction of a greater amount of sample per unit of time which results in a larger amount of analyte being delivered to the detector per unit of time, thereby improving detection limits and detection efficiency.