APPLICATION OF PHOTOACOUSTIC SPECTROMETRY TO FLOW-INJECTION ANALYSIS

Photoacoustic spectrometry (PAS) based on pulsed laser excitation has been coupled to flow-injection analysis (FIA) to detect nitrite, nitra te, iron, ammonia, and phosphate ions in water with the aim to verify its potentiality with respect to conventional FIA systems. Excitation has been performed by means of a Nd:YAG laser with a 2nd harmonic gene ration and a dye laser; a conventional now-injection cell has been use d as photoacoustic cell. Standard solutions and real samples such as g round water, river water, fog and waste water have been analyzed. A go od agreement has been obtained between the results of the proposed tec hnique and those of traditional laboratory techniques. The best analyt ical configuration, in terms of loop length and integration time, has been also defined. The performance as limit of detection (LOD) was com parable for both techniques. The main points to be developed in order to improve the analytical response of PAS-FIA are reported.