Discoloration Array 1
Based on last week’s lab meeting, I made a “solution array” to test discoloration. Specifically, I made 3 solutions of NaHCO3 (0, .23125, .4625, .925 mg/mL) and 3 solutions of NaCl (0.1, 0.5, 1 M). I placed these non-RTP’ed w648 chips in the oven at 37C and took pictures at 4, 18, 72 and 120 hours.
There seems to be a trend and a few puzzling things going on here. The trend was that higher salt concentrations accelerated discoloration at each NaHCO3 concentration. However, low NaHCO3 and high NaCl caused the fastest discoloration (the trend might be that lower NaHCO3 at a given molarity of NaCl cause the fastest discoloration). I expected high NaCl and high NaHCO3 to have discolored first. The NaHCO3 concentrations discolored much more slowly than I expected. Another weird result was that the 1M NaCl chip started to discolor and then stopped.
Are the pHs known? Barcarbonate concentration was just a way of varying the pH.
see next post