Hellma? fluorescence cuvettes, standard cells, Macro with septum screw caps (spectral range 200-2,500 nm, pathlength 10x10 mm, chamber volume 3,500 μL) are available in high-performance Suprasil quartz material. The highest level of sensitivity in the measurement can be achieved by suitably selecting the cell for a specific application such that it exhibits high transmission in the spectral range of interest. The maximum of 80-90% transmission shown by empty Suprasil quartz cell is caused by the reflection loss at the four glass/air boundaries. When filled with common solvents, the cell will exhibit significantly higher maximum transmissions.