Species from the gas phase which are not to be analyzed within the gas matrix or which are possible condensible, or which dissolve in condensing substances are by standard trapped in liquids (solvents) ar brought onto solid adsorbents. Further the liquid solvents can be prepared for subsequent analysis with e.g. gas chromatography and different detector systems. The species adsorbed onto solid phases are either extracted with liquid solvents (solid phase (micro) extraction - SP(M)E) or reevaporated by thermal desorption (TD). Some information about methods applied to tar species analysis in process gases is given below.