Chromatography Forum

Analysis of 8270 analytes soil and water matrices, seeing problems with phenols dropping out, in CCV and LCSs. Usually seems to be 2,4-dinitrophenol and PCP, but can effect the whole group as well.

My first impression is that the phenols are degrading due to use of liners with glass wool. I've found some mention of not using glass wool when analyzing for phenols, but I'm trying to convince a colleague of the problem and moving to using a cyclic double goose neck.

The argument moves to the loss of sensitivity for other compounds when using the cyclic goose neck liners. Could this be due to improper column insertion? I have asked for specific compounds that are losing sensitivity so that I can see if there's a pattern, but it's not clear yet.

I am interested in creating a system that is solid in the science. Your help will enable me to move in that direction, no matter if we start using the glass liners or keep using the glass wool. (I cringe just saying that, but I'm willing to learn!)

TIA

Traces of phenols are likely to be adsorbed on glass wool. Why not just do the experiment of substituting liners ?

Peter

According to my experience, for trace analysis, glasswool is not recommended.

My interest is in using the cyclo double goose neck liners, but I'm getting resistance. I wanted to make sure this was as straight forward as I was thinking.
Thanks.

Jackhandy,

Most of the liners with wool that come from the vendors use way too much wool for 8270. Having said that, I still prefer to use wool so what I tell people is to remove almost all of the wool that normally comes in a liner, leave "a wisp" of wool in the inlet. Also, make sure you use a gooseneck and make sure the column is directly inside the gooseneck. I have had very good luck with that configuration.

Best regards.

I have been having this problem with a new inlet (see my other post). I have been advised that a tiny amount of glass wool is fine, as long as it is silanisd in situ. Also been advised to have column sitting in gooseneck.

Sadly not working for me, but the liners are different volume to last inlet so i might need to play around with them a bit more. I hadn't thought to try a liner without glasswool. Can anyone reccomend suitable aternative? (JAS UNIS 2000 inlet)

thanks

2,4-dinitrophenol and pentachlorophenol are highly susceptible to active sites in the liner.

Definitely make sure the glass wool is silanized, and I have found that the siltek liners from restek work very well for DNP recovery. They have a new "semivolatiles" glass wool, but I haven't tried it.