Hiya All

Does anyone have experience of cleaning the capillaries and change-over
valve on a 253/Kiel?
We think we have a contamination problem as the internal precision and
delta value are OK for a time then there are "bursts" in which the value is
erroneous by up to almost 1 per mille each way. This is for carbon or
oxygen and sometimes both. We think the instrument itself is OK as the
system stability tests check out. The problem may be due to phosphoric acid
finding its way into the capillaries and or contamination from bulk samples
from the Kiel. Baking these parts for a few hours has made no difference.
If contamination is the cause, we shall have to clean the capillaries and
changeover block and valves. We can probably arrange an HPLC pump to pump
liquid through the capillaries and we have ultrasonic baths.  The expense
of simply replacing all these parts is so great that we would prefer to
decontaminate the existing parts if possible.

Regards

John



John Hill
Mass Spectrometry Facility
University College London
Chemistry Department
20 Gordon St.
London
WC1H 0AJ

Tel:  020 7679 4605
Fax: 020 7679 7451
Mobile: 07956 924058