Chromatography Forum

Dear all,
A student of ours is planning to use our HPLC to analyse rumen blood and digesta samples (he'll try to quantify dicyandiamide or DCD, fed to cows to control methane production and post-excretion nitrification - mobile phase = water, flow rate = 0.8 ml/min, T = 30 degrees Celsius, guard column used). I'm wondering if I should get worried that these samples are going to wreck my column. I expect them to be like a sticky syrup, which is a big change from the water samples I've analysing so far. Would anyone be aware of any pre-treament (other than a 0.2 um filtration) required to minimise damages?
Regards,
eddy

To turn any of those materials into a sticky syrup must require some sample treatment already. One immediate problem that springs to mind is that none of the autosamplers that I can think of will handle very viscous liquids.

Peter

Hello.
Ultracentrifugation of blood formic elements by haematocrinic centrifuge and precipitation of blood albumins by tricloracetic acid (or boil water temperature) -it is you way.

Not sure whether your autosampler can handle very viscous samples. Syrup-like viscosity doesn't sound too good.

I am also concerned with the amount of "chemical garbage" that may be present in your sample. Have you considered sample preparation techniques such as SPE?

Of course the other solution is to invest in a guard column

Thanks to all for your replies. The easiest route might be a water extraction (DCD is very soluble in it), which is a procedure used for soil and cow slurry samples. A 1/5 (or 1/10) weight ratio to water could do the trick (I should have thought about that before posting!). That would dilute the samples a good bit and solve the viscosity problem. Said that, I'll certainly keep in mind SPE and precipitation techniques before I start anything.
Regards,
eddy