The present invention relates to devices for the analysis of liquid samples, comprising a rotational-symmetric rotor (1) which is insertable into a sample container (11), wherein an annular gap (32) is provided between the sample container (11) and the rotor (1), and the rotor (1) has at least one flow channel (7) for transporting liquids and/or gases into and/or from the interior of the sample container (11), wherein on the rotor (1) and, optionally, on the sample container (11), means for centred mounting of the rotor (1) are provided.