Why use glass tubes?

[lynch_xiaoyi]

I am new to LC-MS. In the protocol I am using,glass tube was used. I was wondering why we need glass tube? Is it OK that I just use polypropylene tubes instead? Thanks!

[chromatographer1]

Do you have any idea of the amount of plasticizers and impurities found in polypropylene?

Wouldn't it be wonderful to have dozens of unidentified peaks in your chromatogram to challenge you in your analytical work.......... or not?

Glass can be cleaned so easily and well. MtBE is such a wonderful extraction solvent for all those interesting traces found in PP plastic.

Enjoy your research.

best wishes,

Rod

[lynch_xiaoyi]

So how about dichloroform? can I use it for extraction with PP tubes?

or is it necessary to centrifuge after MTBE extraction? the glass tubes we have don't fit any centrifuge instrument in our lab. That's why I want to change glass tubes with PP tubes, then I can centrifuge after extraction.

Thanks for your reply!

[chromatographer1]

You wrote:
" So how about dichloroform? can I use it for extraction with PP tubes?"

Tell me if it will remove extractables from PP?

"or is it necessary to centrifuge after MTBE extraction?"

I have no idea what your samples contain. How can anyone give you a good answer?

best wishes,

Rod

[Don_Hilton]

Strong suggestion: get glass tubes that fit a centrifuge you have access to. Plastics have small molecule components that can be extracted by organic solvents. All solvents will extract stuff - just with varying degrees of efficiency.

Centrifugation is necessary if there are two phases that need to be separated. This may be separation of liquid layers from each other or removal of solid from the liquid. In some cases the phase with the smaller volume may not be observable until it is collected at the end of the centrifuge tube.

[keraunoscopia]

It depends on what you're extracting; I use MtBE and PP tubes all the time, but I'm running target MRMs looking for drugs and won't see any plasticizers I extract. What kind of analysis are you doing?