tekmar standard cross contamination

[danelledees]

Has anyone else had problems with cross-contamination between on-board standards? I have 2 different Tekmar autosamplers: an Atomx and an Aquatek 100. I am having the same problem on both instruments. I'm now using only 1 channel for the IS/Surr Mix and doing everything else by hand because I can't figure out how to stop it.

[James_Ball]

Has anyone else had problems with cross-contamination between on-board standards? I have 2 different Tekmar autosamplers: an Atomx and an Aquatek 100. I am having the same problem on both instruments. I'm now using only 1 channel for the IS/Surr Mix and doing everything else by hand because I can't figure out how to stop it.

Do they use the fixed 1ul rotor valve like the Archon did? If they are using the Valco valve as the 1ul loop for internal standard introduction, those will wear and allow standard to leak from the vial into the loop between samples and cause cross contamination. The only remedy is to replace the vespel rotor, and sometimes even the entire valve is something had happened to make the valve score the rotor.

[danelledees]

I don't think it is the same valves. Certainly not the same as the old Solateks. Everything is PEEK, no metal at all. There is a manifold that holds the standard dispensing valves and then a solenoid valve to introduce it to the sample loop. The contamination is before the solenoid valve. The standards are actually mixing to a degree. I just started running these instruments a few months ago, but looking back, the problem has been there as long as they have been installed. One is only about 9 months old. I'm thinking it must be a settings problem or just a design problem. I get absolutely consistent standard additions so I think the dispensing valves are doing their job.

[RogerBardsley]

Hi danelledees,

I am an Applications Chemist for Teledyne Temar. I have not seen this on our Atomx or Aquatek 100s that we use in the Applications Lab. Our Technical Support staff has more experience with these types of issues. Please call out Technical Support staff at 800-874-2004 and they will be able to answer this question.

Best Regards,
Roger Bardsley