Gratzel et. al. [Anal. Chem. 1999, 71, 2751-2756] describe the use of a diffusional microburet to transfer solutions to very small droplets of solvent. The purpose of their work is to run conventional analyses, such as titrations, on an extremely small scale. For example, in this paper the authors succeeded in adding the fluorescent dye Lucifer Yellow (C13H9N5O9S2) to a 13-picoliter droplet of aqueous buffer. The dye’s final concentration in the droplet was 0.095 mM.
(a) Express the dye’s concentration in ppm and %w/v.
(b) How many grams of Lucifer Yellow are in the droplet?
