Abstract: The present invention relates to a device in gas flow cells for the analysis of chemical substances by spectrophotometry. The gas flow cell has two longitudinal ducts, which are connected by a connection so that a first flow is permitted though the ducts and the connection. The first duct in the direction of flow has a separation column and the second duct is a light guide. The invention is characterized in that in the connection there is a coupling, which is connected with the outlet from an external separation unit. The connection is designed to receive a second flow comprising the substances separated in the external separation unit together with a first carrier gas, so that the second flow is added to the first flow in the connection. The device is designed to function in either of two operating positions, where in the first position the device functions in the conventional manner and where in the second position the first flow comprises the second carrier gas and the second flow is connected up.

Abstract: The present invention relates to a gas flow cell for spectrophotometric analysis of chemical compounds, consisting of a longish preferably cylindrical body (1) with a longitudinal central channel (2) which at the ends of the body (1) is limited by mutually parallel windows (3, 4) which are tightfitting against the channel (2) and transparent for the radiation used at the analysis. The channel (2) communicates at one end with connections (7, 8) for carrier gas and for injection of compounds and has at the other end an outlet (10) for the compounds and the carrier gas. Significant for the invention is that parallel with and at a distance from the mentioned channel (2) runs a second channel (11) serving for separation and connected between the connections (7, 8) and said end of the first mentioned channel (2). In this channel (11) there is a replaceable column tube (12) with filling of known composition.