Clenbuterol

[carras]

Stryder08, The LOQ is 0.1 ng/ml in urine. At this concentration the EU requirements for confirmation are met (see last post by Jerole).
Best Regards

[jerole]

Two thougths: I am assuming that you've tried the procedure with a standard, if that's the case be sure that you have evaporated completely the solvent you've pipeted into the derivatitation vial.

That might be it, we will try again after evaporating the solvent.
By the way, are you from Spain?

[carras]

That`s right, from Madrid.

[jerole]

That`s right, from Madrid.

That's great! I'm from Oviedo. Maybe I could call you if we have still trouble with the reaction?

[carras]

Sure, no problem.

[gpronger]

Has the use of a capillary direct injection been evaluated without derivitization? Looking at its structure, if the hot inlet was avoided, the compound may be sufficiently stable.

[carras]

I have never tried it and I guess it doesn't work well since all bibliography on GC/MS for this compound uses some kind of derivatitation. Anyway, the big problem is unstability in the ion source of the trimethylsylil derivatives which results in a mass spectrum with very limited information. I don't know about boronic derivatives, they are not very popular, though, so they must have their own drawbacks.