Hi, yes in GC the separation of analyte depends on its volatility but we should keep in mind that more polar the compound less volatile it would be,second thing the polarity of column in GC is also very important bcz inside the column the analyte molecules do not travle in a very straight line they move randomly and when they come in contact with the walls of coulmn they stay there for a while depending upon the polarity of analyte and column.
@Jerby7 GC detects relative amounts of some analyte. To find concentrations, usually you do the method of internal standards. You compare the area ratio between what you want as an analyte and some standard which has a fixed concentration of your choice. You make standards of your analyte (using known amounts of the analyte) with the standard to make a calibration curve. From the curve and running your unknown, you can find concentration. That's probably more than what you wanted lol.
@shaggyburns One method I used is called preparative gc. A larger column and a larger volume of injectate is used. As the carrier gas exits the machine, dry ice cooled traps are inserted in the gas stream. Any liquids are thus trapped. Change the trap for each peak on the chromatogram, to isolate each compound. They can then be identified by standard methods, ie IR, NMR, Mass Spec, etc. Another method is to use a GC/Mass Spectrometer. High resolution MS will usually give a unique structure.
Polarity is definitely a factor but, another prominent factor would be the Mr of the substance, as lower Mr would constitute for lower inter-molecular forces and interactions between the components and the stationary phase and higher Mr would constitute for more. More interaction means larger Retention and hence this is why we see a small compound (Ethanol) pop out first (CH3OH) and see a larger compound (Methyl-benzene) pop out second (C7H8).
polarity has more to do with hplc, gc is the simple version og heating ur small liquid sample and breaking down the constituents of ur mixture for u to idenify through retention times and area peaks
The boiling point of methyl benzene is 110 degrees C and the boiling point of methanol is 64.7 degrees C. Methanol is more volatile than toluene. The molecular size of benzene is considerably greater than that of methanol. There are several factors which influence volatility not just one.
@ncpatch If a liquid is viscous that implies that the liquid has resistance to flow. For example petroleum gel and water, which is more viscous? The answer is petroleum gel as it flows more slowly than water across a slanted plane.
How can we separate the Methane and Carbon dioxide by GC? What does three or four peaks refers on GC when separating the methane and carbon dioxide gas? How would you calculate the volume of gases on ml/liters?
Since the mixture is separated by gc, I'd imagine the mass spectrometer analyses the separated peaks too, i.e each individual peak, so more information about the unknown mixture can be obtained.
GC separates compounds and tells you how much of each compound is present but not what the compounds are, so the MS can be used to identify the unknowns
hii friends can any one give me information on what compounds can be dervitized??? and what is the exact method for sample extraction with the use of derivatizing reagents?? lidocaine, procaine mesalamine bupivacaine topermate can any of these be dervatized??
@shoukatkhan01 This has nothing to do with polarity, you maybe talking about HPLC in GLC the more volatile gas are the one that have a boiling point lower than the oven so they remain as gas some components are soluble in the stationary phase so remain less in the helium gas that's why it is known as partition not adsorption adsorption we can talk about polarity, but here we are talking about phase.
Thank you for the video! But I have a question, isn't methanol more polar than methylbenzene? A more polar molecule would be less volatile. Therefore should the first compound that was shown through GC be the more volatile molecule methylbenzene (less polar), rather than methanol?
Learning is fun when snuff is involved? But what if learning was even funer when snuff isn't involved? Maybe they should do a lab test on dat wun der....
Hi,
yes in GC the separation of analyte depends on its volatility but we should keep in mind that more polar the compound less volatile it would be,second thing the polarity of column in GC is also very important bcz inside the column the analyte molecules do not travle in a very straight line they move randomly and when they come in contact with the walls of coulmn they stay there for a while depending upon the polarity of analyte and column.
@Jerby7
GC detects relative amounts of some analyte. To find concentrations, usually you do the method of internal standards. You compare the area ratio between what you want as an analyte and some standard which has a fixed concentration of your choice. You make standards of your analyte (using known amounts of the analyte) with the standard to make a calibration curve. From the curve and running your unknown, you can find concentration.
That's probably more than what you wanted lol.
@shaggyburns One method I used is called preparative gc. A larger column and a larger volume of injectate is used. As the carrier gas exits the machine, dry ice cooled traps are inserted in the gas stream. Any liquids are thus trapped. Change the trap for each peak on the chromatogram, to isolate each compound. They can then be identified by standard methods, ie IR, NMR, Mass Spec, etc. Another method is to use a GC/Mass Spectrometer. High resolution MS will usually give a unique structure.
Polarity is definitely a factor but, another prominent factor would be the Mr of the substance, as lower Mr would constitute for lower inter-molecular forces and interactions between the components and the stationary phase and higher Mr would constitute for more. More interaction means larger Retention and hence this is why we see a small compound (Ethanol) pop out first (CH3OH) and see a larger compound (Methyl-benzene) pop out second (C7H8).
polarity has more to do with hplc, gc is the simple version og heating ur small liquid sample and breaking down the constituents of ur mixture for u to idenify through retention times and area peaks
Fully concept clearing video.
Thnqu RSC.
excellent visualization and explanation.
Viscous means, essentially, how thick the liquid is; e.g. treacle is a very viscous liquid, but acetone is less viscous than water.
The boiling point of methyl benzene is 110 degrees C and the boiling point of methanol is 64.7 degrees C. Methanol is more volatile than toluene. The molecular size of benzene is considerably greater than that of methanol. There are several factors which influence volatility not just one.
@ncpatch If a liquid is viscous that implies that the liquid has resistance to flow. For example petroleum gel and water, which is more viscous? The answer is petroleum gel as it flows more slowly than water across a slanted plane.
I even could separate solid heptamer coupling reaction product having high boiling point with GC
Nice and simple video introduction to GC.
This video is excellent !
splendid explanation
How can we separate the Methane and Carbon dioxide by GC? What does three or four peaks refers on GC when separating the methane and carbon dioxide gas? How would you calculate the volume of gases on ml/liters?
How does the flame ionization detector work? How does it identify a molecule?
Why would you need to use GC and MS together? Do they not both show the composition of a mixture? What benefit is there to using both together?
Since the mixture is separated by gc, I'd imagine the mass spectrometer analyses the separated peaks too, i.e each individual peak, so more information about the unknown mixture can be obtained.
GC separates compounds and tells you how much of each compound is present but not what the compounds are, so the MS can be used to identify the unknowns
Very informative and easy to understand! Thank you!
This was really helpful :). Thank you
Victoria El
how do you know which compound each peak is?
excellent explanation
Thanks, this was very useful!
Can someone help me.. Why is it that we assume that alcohols have equivalent detector responses
Hello. I want to ask about GC TCD-thermal conductivity detector can u show a video about it?
thanks ! this video is really helpful!
Amazing stuff honestly
What happens if the GC test ends half way?
thank you. Made it easy to understand!
Clear demonstration
Amazing video
need more to know. thanks.
I'm only doing this for GCSE and yet I still understand it! And it helped me, thanks!
very nice explanation...THANKS..
Cool, Wish we had all those high tech equipment at my school.
hii friends can any one give me information on what compounds can be dervitized??? and what is the exact method for sample extraction with the use of derivatizing reagents?? lidocaine, procaine mesalamine bupivacaine topermate can any of these be dervatized??
Any one know what viscous means?
thanks
Thanks for posting
Exelente ! ;gracias ,desde buenos aires.
Very interesting.
thank u very much.
very nice. Thanks
Amazing and simple explanation.
@shoukatkhan01 This has nothing to do with polarity, you maybe talking about HPLC in GLC the more volatile gas are the one that have a boiling point lower than the oven so they remain as gas some components are soluble in the stationary phase so remain less in the helium gas that's why it is known as partition not adsorption adsorption we can talk about polarity, but here we are talking about phase.
thank mam it will help me in an interview
I am understand this explanation nice
Thanks!
very nice
good explanation thankyou
Video doesn't work
Thanks....
nice
Thank you for the video! But I have a question, isn't methanol more polar than methylbenzene? A more polar molecule would be less volatile. Therefore should the first compound that was shown through GC be the more volatile molecule methylbenzene (less polar), rather than methanol?
GC Video
Forget this.
Gas Chromatography GC
Learning is fun when snuff is involved? But what if learning was even funer when snuff isn't involved? Maybe they should do a lab test on dat wun der....
putz tem alguem aki que fala portugues não né?
Nice vedio
+hoba mohamed *video
its nice
hoba mohamed
salve pra quem veio pela gc
Salut le M1 A&C! On s'éclate! lol!
Warwick universiti xDD
Good explanation. ..
thanks
thank you very much