Bis-tris-propane: temp. coeff. (dpKa/dT) ??

[Frank R. Gorga]

Achim Recktenwald wrote:
> 
> Hi all,
> 
> I am looking for the temperature coefficient(s) [dpKa/dT] of the
> buffer-substance
> 'bis-tris-propane' = 1,3-bis[tris(hydroxymethyl)methylamino]propane
> for some enzyme kinetic experiments.

According to the booklet titled "Buffers" which is free for the asking
from Calbiochem (p16)... the delta pKa / deg. C for BIS-TRIS-PROPANE is
-0.016.

The Calbiochem buffer booklet is ESSENTIAL reading for anyone using
buffers and (IMHO) should be reread often!

> 
> According to the supplier (Sigma) it has the pKa-values:
> pKa1=6.8 and pKa2=9.0 at T=25C.
> 
> Sigma doesn't know the dpKa/dT-value(s) either.

Shame on them!

--- Frank

***********************************
Frank R. Gorga, Ph.D.
Dept. of Chemistry & Biochemistry
Duquesne University
Pittsburgh, PA 15282
412-396-5858 / 412-396-5683 (fax)
gorga at next.duq.edu