Figure 8
From: Pre-analytical challenges from adsorptive losses associated with thiamine analysis
Recovery of thiamine following filtration of 125 mL 100 nM thiamine in HPLC grade water pH adjusted to 4.5 through 0.2 µm polyethersulfone (PES), GF/F glass fiber (0.7 μm pore size) and GF/C glass fiber (1.2 μm pore size) membranes relative to the pre-processed sample and that passed through the plastic filter housing and flask only. (a) The concentration of thiamine recovered in the filtrate. (b) Concentration of thiamine recovered from the filters after vortexing filters in 2 mL alkaline potassium ferricyanide. The results are after conversion of (a) thiamine remaining in solution and (b) the filter-retained thiamine to thiochrome using alkaline ferricyanide with fluorescence detection at λex = 360/9 nm, λem = 450/15 nm.
