Chromatography Forum

I am running 524.2 and have lost 2,2-Dichloropropane! I have read that it can be contributed to trap wear, but changed my trap (Vocarb 3000) and still didn't see it. I am running a 5973/6890 with Aquatek 100/Stratum. I would appreciate any suggestions. THANKS!

I am running 524.2 and have lost 2,2-Dichloropropane! I have read that it can be contributed to trap wear, but changed my trap (Vocarb 3000) and still didn't see it. I am running a 5973/6890 with Aquatek 100/Stratum. I would appreciate any suggestions. THANKS!

How long does the sample sit before being purged and how warm is your room?

Before we started using a chilled autosampler we had trouble with this compound. It breaks down quickly at room temperature. Keeping the room below 70F helps a little but not like having an autosampler chilled to 5C.

Usually what I saw was the first standard of the day was ok, but if I put one on before I left in the evening that would run during the night that one would fail for 2,2-Dichloropropane.

I do have the samples on a chiller, but at 10 degrees. And they don't sit at room temperature for long. Good idea though - keep them coming!

If you run samples with high salinity you can contaminate the system with salts which can break down the halogenated compounds, though it is a much worse problem if you are using nickle transfer lines.

Is the loss something recent or has it always happened with this system?

Using the procedural standards preserved with HCl can cause some degradation of the flow paths over time which will lead to active sites with similar results as the salt contamination.

The only Tekmar unit I have used was an LSC2000 so I am not familiar with this one. What type of water management does it use? I know on the EST Encons we have to replace the moisture traps as they become active over time.

If I can think of anything else I will post it.