Development of a Novel Detector for Flow Injection Analysis Based on Optical Beam Deflection Induced by the Reaction Heat

Abstract

A novel detector for flow injection analysis has been developed based on the optical beam deflection induced by the chemical reaction heat. A new flow cell was designed, in which the lower part is filled with CCl4 and an HCl solution is flowed above the CCl4 phase. An NaOH solution is injected into the flow line to react with the HCl. The neutralization heat is transferred to the CCl4 phase, thus generating a temperature gradient. This temperature gradient induces a refractive index gradient which, in turn, generates a deflection of a probe beam that is passed through the CCl4 phase. The effects of the flow rate and the length of the cell on the deflection signals have been investigated. The deflection signal was found to be proportional to the concentration of NaOH in the range of 0.05 to 0.5mol/l by using the flow cell. The detection limit of the NaOH concentration was about 0.05mol/l. Another type of the flow cell is also discussed.