The complex is 13% by mass of the absorbing element (Copper K-edge). The solvent will be acetonitrile and by control the concentration, I mean that I can dictate how much of the sample may be put into the capillary. I won’t be able to control the amount of the absorbing element. Rachel Wallick Chemistry Graduate Student | van der Veen Group University of Illinois at Urbana-Champaign 3011 Materials Research Laboratory