AAA, perspective- a reply

Mahrenholz, Alan M (amahrenh@iupui.edu)
Thu, 10 Jun 1999 10:14:36 -0500

I'll take a chance in responding to this "perspective" query (copied
below). Since James seems willing to abandon PTC amino acid analysis on his
system, I'll admit I was using a very similar Beckman setup where we
performed some GLP AAA analyses. However, I was using Waters AQC chemistry
and columns (yes, detecting UV with the 166). I did have the 507
autosampler- I just used the column heater as a place to nest the column -
ambient temp was OK. Note this was the newer 15cm AQC column which would
fit the column heater when coupled with the Newguard column (requisite in
order to obtain reasonable column lifetimes). I was able to get the
chromatography worked out pretty well adapting directly from published
procedures - it did function acceptably. The chemisty was very convenient,
although it has a few limitations, especially working in UV. In sum, you
could make a go of it using your existing equipment, but as usual, if money
is not a problem you would be more comfortable with the performance of a
newer, dedicated system as you mentioned.

James Freedy wrote:

I am involved in amino acid analysis of a particular
glyco-protein,for release testing. My efforts are in support of a validated
method.Currently our QC lab is and has been release testing based on
theP/E-ABI,PTC, derivitization and subsequent separation on c-18 R/P
chromatographysystem. As I perceive the story, this instrumentation is no
longer beingsupported and what little support there is, now, will
eventuallydisappearall together.
So to make a long story short, we now have in our laboratory, a
system which has Beckman's name on it, to be exact; 126AA solvent
module,166 detector, 232 post column reactor, 507 system gold autosampler
and a350IBM Personal computer. I have been validating this system and find
thatitworks acceptably well, but the autosampler is something from a
differentrealm. I understand that Beckman makes a 508 autosmpler which does
nothavea column oven incorporated into it's design. Any experience with
thissituation would be appreciated. Should I up-grade to the 508 and buy
acolumn oven, which by the way would have to be programmable to
accommodatethe chromatography or should I struggle along with the current
autosampler which uses three times the actual amount of sample needed for
injection. Another option would be to switch the whole post column ninhydrin
systemover to an HP1100 or a Waters Alliance system any and all constructive
comments would be appreciated.

James G. Freedy
Ortho Biotech
Raritan, N.J.