Chromatography Forum

Dear all:

I am a learner of GC and now I want to use MSTFA derivatization, but there is a problem to seal the TMS silyl agents while silyling and seal up the products for their volatilization and water fearing. I want to know which kind of bottle and cover can be used in this program.

thanks!

We use trimethylsilyl derivatization reagents all the time. We purchase in 5 g bottles sealed with a septum cap (e.g. Pierce, Regis). We normally use BSTFA here, and use a 250 ul or 500 ul glass syringe to withdraw the reagent. Purchasing in small sizes enables us to go through the bottles quickly and minimize chance of contamination or degradation.

I used what is commonly called a pyrex culture tube with a teflon lined screw cap to incubate my reaction solutions to make TMS ethers.

We add sample solution and BSTFA to autosampler vial, cap, mix, and inject (can be immediately). For amines, we heat about 15 minutes as well.

Thanks for giving me good suggestions. I am a learner of GC/MS and I want to use TMS derivatization metabolites. When I use MSTFA dervatization, I get very few amino acid derivatives, I don't know how to imporve my protocol. My protocol as following:
1. Deprotein with double volum of methanol, After centrifugal and move the liquid layer to the derivazating vail and dried by speed vac.
2. 80ul 20mg/ml methoxyamine hydrochloride in pydine was added at 37℃ for 90min, then 80ul MSTFA was added at 30℃ for 30min and at room temperature for 120min, then sampled.

What I want to know is
1. whether my step of deprotein affect my analysis and is there any better way to do this.

2. how to improve my protocol according to your experience!

thanks very much!