A system for containing a sample for analysis by a spectrometer, comprising a sample container unit (1) having a well (4, 13, 213) for containing the sample, the well comprising a well inner wall (5, 21, 22, 23, 23a, 34, 234) and a well bottom plate (20), a bottom plate aperture (32 ', 32, 232) in the well bottom plate (20), and comprising a first spectral element (31', 31, 231) spanning an opening of the bottom plate aperture (32 ', 32, 232), wherein the well (4, 13, 213) further comprises a sealing material (33 ', 33, 233) at the interface of the inner wall (5, 21, 22, 23, 23a, 34, 234) with the first spectral element (31', 31, 231) wherein radiation freely passes through the base plate hole (32 ', 32, 232) to the first spectral element (31', 31, 231).