Chromatography Forum

Good day,

I'm running through needles faster that toilet paper. My Samples are dried and derivatised with BSTFA:TMCS:Pyridine (5:1:1 ratio). I used to use hexane and pyridine (two separate washes), but now uses IPA:Acetone (1:1 ratio) with slightly better (albeit still unsatisfactory) results.
Also, we seem to get better mileage during the cold-dry months, but the problem is aggravated during the warm (very humid) summers in central South-Afirca.

Please advise

P.S. Please also indicate your preferred wash method (amount of washes before and after injections)

I'm running through needles faster that toilet paper.

I used BSTFA regularly (several times a week) for over 35 years. We had HP/Agilent GCs and GCMS units, and I simply used 3 pre-washes and 3 pumping, and would use DMF or pyridine as the wash/rinse solvent.

Are you really having a problem with needles (clogging or bending?) or is your issue with bending plungers? We occasionally had issues with needles sticking with some of our assays.

Do you mean needles or syringes ?

Peter