Hello All,
Bob Cudney sent me the email below (forwarded with permission), in which
good instructions are given for the pHing process. Use it in good health.
JPK
*******************************************
Jacob Pearson Keller
Northwestern University
Medical Scientist Training Program
Dallos Laboratory
F. Searle 1-240
2240 Campus Drive
Evanston IL 60208
lab: 847.491.2438
cel: 773.608.9185
email: j-kell...@northwestern.edu
*******************************************
----- Original Message -----
From: "Bob Cudney" <b...@hrmail.com>
To: "Jacob Keller" <j-kell...@md.northwestern.edu>
Sent: Wednesday, April 22, 2009 8:41 PM
Subject: RE: [ccp4bb] Jeffamine M-600 pHing recipe
Hello Jacob:
It takes about 132 microliters of concentrated HCl per every gram of
Jeffamine M-600 to get the pH to 7.5 at 25 degrees Celsius. From there, one
can titrate to pH 7 using dilute or 1.0 M HCl to the desired measured pH.
For example to make 100 ml of 50% v/v Jeffamine M-600 pH 7.0, weight out
49.15 grams of Jeffamine M-600, add water and 6.5 ml of concentrated HCl to
bring the pH to 7.5. Then titrate to the desired pH with the solution
volume as close to the desired final volume (to avoid pH changes due to
dilution), determining the final volume using a volumetric flask. Sterile
filter using a 0.22 micron filter into a sterile container (glass or PETG
plastic).
The Jeffamine solution will warm significantly during titration so be sure
to use a pH probe with temperature compensation or better yet cool the
solution to 25 degrees Celsius before pH measurement. We recommend making
final pH measurements at 25 degrees Celsius and not relying on temperature
compensation.
Titration in a hood with the appropriate safety gear in place is encouraged.
Or take the easy way out and order HR2-501 Jeffamine M-600 50% v/v solution
pH 7.0 - 200 ml from Hampton Research :-)
Kind Regards, Bob Cudney
Hampton Research
34 Journey
Aliso Viejo, CA 92656-3317 USA
Telephone (949) 425-1321 extension 200
Fax (949) 425-1611
b...@hrmail.com
www.hamptonresearch.com
