Photo-Pyroelectric Spectrometry and its Application to Flow Analysis

点击翻译按钮获取中文摘要

Photo-pyroelectric spectrometry (PPES) with a compact sensor probe including a PZT pyroelectric ceramic piece and a He-Ne laser as an excitation source was studied. The signal induced by the laser irradiation in a mode of step function or in a modulated mode could be explained by a classic theory on heat conduction. The detection limit was determined as 1.6 x 10^<-4> cm^- in the Napierian absorption coefficient. The PPES was applied to batchwise colorimetric determination of phosphate and ammonia in natural water on the basis of the heteropoly blue method and the indophenol method, respectively. The detection limit was 2.7 ppb for PO_4^+-P and 2.1 ppb for NH_4^+-N. Further, flow analysis was tested by using the PPES. The detection limit was 0.97 x 10^<-4> cm^<-1>, which was slightly better than that of the batchwise method. This shows that the PPES is available for a detector in the flow analysis. The flow injection analysis for phosphate and silicate was performed by using the PPES. In order to use the PPES practically, the use of a laser diode with high power and improvement of the flow cell and the PZT sensor probe are desired.