I'm helping a Grade 11 student doing an EE on determining lead soil content. We found a good, doable procedure for it, but one of the reagents is a borate buffer that doesn't seem to have a recipe anywhere!
Here's an excerpt from the paper:
A sodium tetraborate buffer solution with the concentration of 0.05 M (with addition of NaOH, 1M) was prepared by mixing nearly the appropriate amounts and adjusting to pH = 6 by the addition of a few drops of HCl solution.
Everything I've seen on tetraborate buffers gives a basic pH (~8 at the lowest), so how does this one work? And with borate being as complicates as it is, what are the appropriate amounts?
If anyone can help, I'd really appreciate it. Thanks!