Gas chromatography Houdková Zdeňka
Separation metod - separation of anlytes in the gaseous phase The compounds are separated on the basis of different migration in the system two phases – stationary and mobile The compound is carried with mobile phase through the stacionary phase in column. Here are individual component with different retention that are succesively eluted from the column with mobile phase. For evaluation of signal detectors are used.
Phases - mobile (liquid, gas) = carrier gas – H 2, N 2, He, Ar must by chemically inert must by chemically inert - stationary ( solid, anchored liquid) – silicone oil Sampling - inject sample through septum - multiway-cock - autosampler sampling volume µl or 1-5 µl sampling volume µl or 1-5 µl
Columns - packed - metalic (Al, Cu) glass – diameter 6 mm, lenght 3-5 m 3-5 m - capillary – (plastics, glass) – diameter 0,25 mm, lenght m lenght m Capillary column Capillary column
Detectors - evaluation of analytical signal - thermal conductivity, flame-ionization, electron capture detector, He-detector Thermal conductivity detector Flame ionization detector
Application of Gas chromatography Enviromental analysis – pesticides, poly cyclic hydrocarbons, determination of water, CO 2 … Organic analysis Analysis of foods Analysis of fuels
compound – sloučenina component – složka, prvek on the basis – na základě carry – hnát, nést column – kolona retention – zadržení succesively – postupně elute – vymývat anchored liquid – zakotvená kapalina sample – vzorek multiway cock – více cestný kohout migration – migrace, putování autosampler – auto dávkovač packed columns – náplňová kolona diameter – průměr evaluation – vyhodnocení Flame ionization detector – plameno-ionizační detektor Thermal conductivity detector – tepelně vodivostní detektor Electron capture detector – detektor elektronového záchytu