Chromatography Forum

I'm totally new to the world of organics (via Inorganics) and I need some serious advice. I'm required to strickly adhere to SW-846 methodology.

First I used CKD for my LCS – all but the last surrogates were lost. Then I got a hold of some sand. It’s been cleaned and dried. I re-prepped the LCS with sand and I still lost all surrogates but the last. The surrogates are right where they need to be in the CCV. Looking at QEdit: the Fluorophenol peak is there but no integration, Phenol-d6 has an integrated peak but the screen showing Scan 502 also says Corrupt at the end of the title, Nitrobenzene-d5 and Fluorobiphenyl are at about half of what they should be, Tribromophenol is no where to be seen, and lastly Terphenyl-d14 no problems with the peak or concentration value. I’m in need of wisdom. I assume the surrogates are being lost in sample prep. How? Why? By the way, there is no problem with any of the SVIS. The surrogates in the Method blank are between 64 and 79% of the known concentration, the last one is at 95%.

ydm27,

Notice that your acids are gone but your blank basically worked? However, you don't say anything about your spike compounds in your LCS? I would look at how basic the sand is.

Terphenyl is a heavy neutral so relatively unaffected by KD and pH. Thus the good recovery. I would also look at how aggressive the KD is, especially how hard your are pushing to get a low final volum by KD.

Best regards.