RE: Big peaks in PTH
Mark W. Crankshaw (crank@pharmsun.wustl.edu)
Wed, 6 Jan 1999 11:02:34 -0600 (CST)
To follow up on Chris Clogston's reply, the R4A problem we saw ca. 470A days
was not valve block failure. We experienced R4A bridging, i.e. when the R4A
was delivered to the conversion flask the droplet would bridge over to the
other
lines coming into the flask. The suspended R4A would not dry down as normal
and when the S4B would deliver and bubble up during mixing prior to the
sample loop load transfer the retained R4A would contaminate the S4B and
subsequently cause
a huge UV absorption in the 120A chromatogram. Judicious trimming/placement
of the lines entering the flask was the fix. Mark.