A question for the chemists here:
Why do I *not* get precipitation when freezing these PG-based concentrates? I put Trial-130119 in the freezer overnight, and like D316, there is no cloudiness nor precipitate. Based on lack of precipitation, I recommend that these be frozen. But I'm wondering: why no precipitate?
Trial-130119 takes longer to dissolve the ascorbic acid at 75C due to its higher concentration and lower proportion of metaborate. So I'm closer to the solubility limit. Yet no precipitation when frozen. Odd.
@Mr Bill - Thanks for the note. You're right, and I hadn't thought of that: I still measure the water by volume because it's impractical to weigh such a large volume and a beaker is accurate enough.
Finally, the curve for Trial-130119 with 45 g/L of sulfite (reduced from 50 g/L in my prior posting) has this curious trait: The toe matches Xtol, and the highlights match D316. Here are all three curves for Delta 400:
The toes are the means of two frames, and my goal of all this was to remove the softness in the toe of the green curve (D316).
Last edited by albada; 01-22-2013 at 07:53 PM. Click to view previous post history.