Study of sensitive photoacoustic spectrometer and biological application

A sensitive intracavity photoacoustic spectrometer,which consists of a CO/CO2 laser, a longitudinal resonant photoacoustic cell, a plant gas sampling system and a computer control and data processing system, is able to measure many kinds of gases relevant to plant trace gas exchange. The sensitivity limit of the system for ethylene measurement is 2×10-11.The system is applied to the study of stress reaction of nectarine fruit exposed to O3 by monitoring the variation of the ethylene production. The measurement is helpful for the study of fruit postharvest biology and preservation technique.