Flame sealing a sample in a glass tube under vacuum.

[@augustotiberio]

Really informative! Thank you very much for sharing your knowledge!

[@ScientificGlassblowing]

You are welcome. Thanks for watching.

[@AshutoshSingh-kz2qw]

Really informative. Thank you. I was literally stressed. Now, I know what to do!

[@ScientificGlassblowing]

glad to hear that this helped.

[@jayw2324]

Thanks for the video, very helpful

[@ScientificGlassblowing]

I am happy the video helped.

[@Sharkie1717]

Thanks for the demonstration. Was wondering how it could be done under vacuum.

[@ScientificGlassblowing]

In this demo, we are using a vacuum.

[@sshsdom5861]

cool man.

[@ScientificGlassblowing]

thks

[@Noddles320]

Whats the name of the sandwich vacuum pump

[@ycchan9037]

I have an issue that keeps bothering me: I want to make some essential oil sample seal in 1ml amber vials. However since the glass vial is so small and essential oil highly flammable, using high heat to seal off the vial seems dangerous. Any suggestion on this? Thx

[@ScientificGlassblowing]

The method I have used to seal flammable liquids in glass tubes (NMR samples or Elemental analysis) is to freeze the sample in liquid nitrogen. When the sample is frozen, place it under vacuum then seal off the tube. HOWEVER, if you do not have the correct training and equipment, Schlenk Line, liquid nitrogen,... you should NOT attempt this.

[@ycchan9037]

@@ScientificGlassblowing Please tell me more about this. Will liquid nitrogen contaminate the sample (essential oil)? Can I get these things done in a university? Or do I have to search for some specific lab to do this? I am situated in Hong Kong, thank you

[@ScientificGlassblowing]

The liquid nitrogen will freeze your sample (under vacuum) there shouldn't be any contamination issues. Most Chemistry departments will have liquid nitrogen and a good vacuum system.

[@ycchan9037]

@@ScientificGlassblowing I see, but in normal circumstances, do these department in the university have the equipment to seal glass?

[@ScientificGlassblowing]

Maybe. 🤷‍♂️

[@ملكيوسف-ل5م]

What if the ampoule is quartz and want to sealing it in the glove box because it's very sensitive to air?

[@ScientificGlassblowing]

Quartz requires a much higher temperature a hydrogen/oxygen fuel mix is required. I don't have any experience with quartz, that's on my "to do" list this year.

[@CoincidenceTheorist]

Probably won’t be much info on doing the opposite. Which is creating a sealed sample under pressure. A basic very vague reasoning for creating such a situation is for study/experimentation regarding piezo electret fields and electrets in general.

[@ScientificGlassblowing]

The glass would expand and pop if you heat a closed tube that is not under vacuum.

[@ether4238]

What type of glass ? Lab glass will not melt as easy... I need to do liquid sealed in glass.

[@ScientificGlassblowing]

I am using borosilicate glass.

[@MichaelWysocki-ks5xt]

Sounds like liquid nitrogen freezing would make a mess of it. Couple thousand degrees to hundreds below zero within a couple inches .

[@ScientificGlassblowing]

No, it's fine. If your sample is in an organic liquid you must freeze it. Otherwise, when you pull a vacuum the solvent will boil.

[@MichaelWysocki-ks5xt]

@@ScientificGlassblowing I was thinking of the glass

[@jcp1108]

Hi! Can I use this same technique to seal a quartz tube?

[@ScientificGlassblowing]

Hi Julieth, A fuel mixture of natural gas and oxygen is not hot enough to fuse quartz. You need a hydrogen-oxygen mix to fuse quartz. The technique would be the same or very similar.

[@jcp1108]

Thank you very much for your answer!

[@CoincidenceTheorist]

You could also use nitrous butane.

[@ChrisHillASMR]

This is really poorly done, thank God you're not a dentist.

[@ScientificGlassblowing]

Pulling teeth is more of a hobby.