Different concentrations of HSAff in water measured on module B with a standard 0.02 cm and 10 cm pathlength × 3 mm-diameter microcell (spectra unsmoothed, water baseline subtracted). Black line: 10 µM solution in standard cylindrical cell with 0.02 cm pathlength. Grey line (red online): 10 nM solution in a microcell with 10 cm pathlength. CD and high-tension (HT) data are shown by the solid and dashed lines, respectively. Spectra were normalized at 210 nm. Lower figure: (A) Photograph of the 10 cm micro-flow cell (Starna). (B) Open door of the sample house compartment with cell holder. The 3 mm-diameter cylindrical sample cavity of the flow cell is designed to accommodate about 0.7 ml of sample.