Getting rid of percipitate in Ringer solution? - (Feb/03/2012 )
I am trying to make a Ringer solution. I followed the ingredient list from an article perfectly and had a co-worker double check my calculations. I adjusted the pH as needed with HCl. The chemicals dissolved completely and the solution looked homogenous. Then after autoclaving and sitting for a day, I'm starting to notice a pretty significant percipitate. Any ideas?
Did you use MilliQ water? If not, you may have calcium in the water which will sometimes form a precipitate with phosphates.
I did actually.
Which of the many Ringer's solution recipies are you following?
It is specifically for an Insect Ringer. It was published in the Journal of Insect Physiology in 2011 by Laughton et. al. The solution contains 128mM NaCl, 18mM CaCl2, 1.3mM KCl, and 2.3mM NaHCO3 in 1L dH2O. I have emailed the authors and they said their solution never has any percipitate complications unless the sodium bicarbonate becomes too old, but all of our chemical were just ordered from Sigma.
That should be fine, I can't see any reason why it would precipitate at all.
I make that (per litre): 7.48 g NaCl, 2 g CaCl2.2H2O, 0.097 g KCl and 0.19 g NaHCO3, just to check that you havn't made the solution extra concentrated somehow.
That's exactly what I got as well. I have done this three seperate times not and each time I get a significant amount of percipitate. I'm not really sure what to try next, but thank you for your help anyways. I may try filtering and then testing the pH again to see if I'm significantly off. Otherwise, I supposed it could be an issue with the chemicals, but that is extremely unlikely.
Could it be precipitation of calcium carbonate?
Add your chemicals in this order:
1- NaCl
2- KCl
Mix those two first. After they're completely dissolved, add
3- CaCl2-H2O
After it dissolves completely, finally add
4- NaHCO3
it could be that your glassware is contaminated with detergent and you are seeing calcium phosphate precipitate.