There are about 6 factors which will influence the retention time of the compounds in GC; Volatility of the compound Polarity Column temperature Column packing polarity flow rate of the carrier gas and length of the column Volatility will have the greatest influence on the separation. Polarity is only important if you are separating compounds with widely different polarities. Good luck on your project.

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.

@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.

@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.

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

Viscous means, essentially, how thick the liquid is; e.g. treacle is a very viscous liquid, but acetone is less viscous than water.

I even could separate solid heptamer coupling reaction product having high boiling point with GC

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.

excellent visualization and explanation.

Fully concept clearing video. Thnqu RSC.

@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.

Nice and simple video introduction to GC.

This video is excellent !

splendid explanation

Very informative and easy to understand! Thank you!

Cool, Wish we had all those high tech equipment at my school.

excellent explanation

I'm only doing this for GCSE and yet I still understand it! And it helped me, thanks!

Clear demonstration

Thanks, this was very useful!

Amazing stuff honestly

thank you. Made it easy to understand!

thanks ! this video is really helpful!

This was really helpful :). Thank you

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?

thank mam it will help me in an interview

Amazing and simple explanation.

very nice explanation...THANKS..

need more to know. thanks.

Amazing video

I am understand this explanation nice

How does the flame ionization detector work? How does it identify a molecule?

Thanks for posting

thanks

Exelente ! ;gracias ,desde buenos aires.

Good explanation. .. thanks

Can someone help me.. Why is it that we assume that alcohols have equivalent detector responses

thank u very much.

very nice. Thanks

Thanks!

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?

thank you very much

good explanation thankyou

very nice

Very interesting.

GC Video

how do you know which compound each peak is?

Hello. I want to ask about GC TCD-thermal conductivity detector can u show a video about it?

What happens if the GC test ends half way?

@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.

Thanks....

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??

Forget this.

nice

Any one know what viscous means?

Gas Chromatography GC

salve pra quem veio pela gc

Video doesn't work

putz tem alguem aki que fala portugues não né?

Nice vedio

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....

Salut le M1 A&C! On s'éclate! lol!

Warwick universiti xDD