1. A device ( 120 ) for inspecting a volume and a composition of a sample ( 4 ), said device comprising: (a) a pipette ( 1 ), in which an interface is formed between the sample ( 4 ) and a first fluid ( 6 ) which is adjacent to the sample ( 4 ), said interface being optically perceptible outside the pipette ( 1 ) as an interface line ( 4 a ) between the sample ( 4 ) and the first fluid ( 6 ) that extends about horizontally; (b) a camera ( 10 ) with a marking ( 15 ), which is arranged in an image field of the camera ( 10 ), such that the interface line ( 4 a ) and the marking ( 15 ) can be reproduced in a recorded image ( 12 ), with the pipette ( 1 ) being arranged between a light source ( 20 , 20 a - 20 e ) and the camera ( 10 ), such that a spectrum ( 13 ) of light beams ( 22 - 24 ) of the light source ( 20 , 20 a - 20 e ) that have passed through the sample ( 4 ) can be recorded by the camera ( 10 ); and (c) an evaluation unit ( 101 ) such as a computer or PC, which compares the marking ( 15 ) in the recorded image ( 12 ) with a position of the interface line ( 4 a ) and in which the evaluation unit ( 101 ) comprises additional means which compare a recorded spectrum ( 13 ) with a reference spectrum and determine whether the composition of the sample ( 4 ) in accordance with the recorded spectrum ( 13 ) corresponds to that of the reference spectrum.