Abstract: A CO laser emitting radiation between 1300 and 2000 cm$+$MIN@1$/ is applied to monitor trace gas emissions using photoacoustic detection. Several biologically interesting gases can be detected by tuning the laser frequency to absorption bands of these species. The sensitivity of the system reaches the ppbv level (acetaldehyde: 0.1 ppbv, ethanol: 3 ppbv, C$-2$/H$-6$/: 1 ppbv) allowing us to study e.g. an individual piece of fruit. The selectivity is enhanced by a cold trap kept at a temperature between 0 and minus 180 degrees Celsius so that unwanted species can be frozen out. The biological sample is placed in a continuous flow system of a few liters per hour which leads the released gases from the sample to the photoacoustic cell, thus creating an on-line and non-intrusive technique. !14
展开▼
机译：摘要：CO激光发光辐射在1300和2000 cm $ + $ min @ 1 $ /应用于使用光声检测监测跟踪气体排放。通过调谐激光频率以吸收这些物种的吸收带，可以检测几种生物学上有趣的气体。系统的敏感性达到PPBV水平（乙醛：0.1PPBV，乙醇：3 PPBV，C $ -2 $ / h $ -6 $ /: 1 PPBV），允许我们学习。一个单一的水果。通过在0到180摄氏度的温度下保持的冷阱增强了选择性，从而可以将不需要的物种冻结出来。将生物样品置于每小时几升的连续流动系统中，这导致从样品到光声电池的释放气体，从而产生在线和非侵入式技术。 ！14
展开▼
