1. A method for the optical analysis of a sample liquid ( 34 ) contained in a sample container ( 24 a - h ), wherein the sample liquid ( 34 ) contains at least one substance ( 40 ) in an at least partly dissolved form, comprising the steps of: providing at least one sample container ( 24 a - h ) filled with a sample liquid ( 34 ); illuminating the at least one sample container ( 24 a - h ) by means of a light source ( 18 a - h ); and capturing an image of an identification pattern ( 32 a - h ) associated with the at least one sample container ( 24 a - h ) by means of an image recording device ( 22 ) which generates image data, wherein the optical path (OP) is selected in such a way that the sample liquid ( 34 ) contained in the at least one sample container ( 24 a - h ) is at least partly situated between the image recording plane ( 36 ) of the image recording device ( 22 ) and the identification pattern ( 32 a - h ).