Tube sampling, chemical constituents

Gas chromatography (GC) is a chemical analysis technique for separating chemicals in a complex sample. In a gas chromatography setup, the sample is passed through a narrow tube known as the column, through which different chemical constituents of a sample pass in a gas stream (carrier gas, mobile phase) at different rates depending on their various chemical and physical properties and on their interaction with a specific column filling, referred to as the stationary phase. Interaction of the analytes with the stationary phase causes each one to exit the column at a different time (retention time). Separated chemicals are detected and identified at the end of the column. Miniaturization of GC systems can lead to small size and extremely low power consumption. 

No chemical interactions between the sample solution and PZT. Especially aggressive, acidic solutions can dissolve constituents out of the PZT material. The impurities can cause photoacoustic perturbation signals which create much interference in weakly absorbing solutions. The use of bare piezooeramic disks or piezoceramic tubes as a sample container represents an undesirable source of contamination. It is found that even surface-treated (gold-plated) piezo tubes are not resistant to many acids. 

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