Gas chromatography | Chemical processes | MCAT | Khan Academy

[@hollywoodbb]

I’m a chemist and use multiple GCs every day. In my line of work, we’re more interested in how MUCH of a compound is in a sample rather than trying to identify a compound. But we also do look for the presence of a compound in certain scenarios. GC is excellent for both applications. To all you students, YES you will actually use these everyday if you go down a chemistry route. Familiarize yourselves with them. In my lab, titrations are also pretty prevalent as well as spectrometry and moisture analysis. A lot of it is automated which is a breeze, but we do manually perform some of these techniques. Chemistry is MUCH harder in college than in the field and I know how defeated I felt at times as a student. Hang in there and stay on the path! I enjoy my job now and at 26 I made 6 figures this past year. It’s worth it, I promise!

[@pearlz4796]

how far did you get into your education?

[@hollywoodbb]

@@pearlz4796 I completed a 4 year degree and got my Bachelor of Science in Biological Science.

[@NewWesternFront]

How did you secure employment?

[@lorechadominic4920]

Thank you😅

[@hollywoodbb]

@@NewWesternFront I knew the company was hiring and just submitted my resume and the company had 2 people leaving, so they were in need of replacements. And I did really well in the interview. A lot of times it’s just timing, too. Tips: Really polish your resume and spend some time curating it. If you can get past that first step, then you can really shine at the interview! Before you go into the interview, look up facts about the company and familiarize yourself with it. In my interview, the first question was, “So tell us what you know about the company?” And luckily I was able to speak for a minute or so about them, which they seemed to really like. It shows that you’re invested and aren’t just going to say, “idk I just want a job.” Also, knowing someone in the field definitely helps if you have that luxury. If you’re still in school, make sure to network and stay on good terms with your professors. A recommendation can go a long way. Oh and lastly, to my surprise, they hardly touched on chemistry in the interview. Most places just want you to have a basic knowledge/education of the field, then they’ll train you on the job the way they want. I think the only chem related question they asked me was which techniques I was familiar with. I basically just rattled off the analyses I had done in my labs (titrations, GC’s, capillary action, pH, etc.) and they essentially told me the main ones I’d be doing, and they would train me on the specific instruments. They mainly wanted to know how I work with others, if I can provide attention to detail, am I teachable, etc.

[@MiowHouse]

Explained a million times better than my lecturer in a fraction of the time...thank you

[@basharkhan6779]

thanks

[@f.r.i.e.n.d.l.y]

its been 10 years...what you doing now?

[@NathanielIReiff]

10+ years out of high school and I’m still using the Khan Academy!

[@korykubasek347]

khan academy has made my college life so much easier keep it up!

[@elvinhasanaj9849]

You saved me big time with this video. The explanation was clear and straight to the point summarized 50 textbook pages in 8min. I love u guys.

[@henriklarsen8193]

You're doing a marvelous job, even at making chemistry sound adorable (the baby / sumo part)!

[@syu11079]

great video! before stumbling on this video i spent ages reading textbooks, but still didnt quite get GLC. but your video explained it perfectly, so thank you! :)

[@simflorianwilliam8617]

The only good thing about this channel is, I always like the video before playing it, iam loving gas chromatography now 😊

[@sbmuthuraman]

Gas chromotography was explained in a simple manner and in detail covering most of the aspects of GC.

[@marlonhowe7592]

This is awesome (-: I always use English explanation videos for Chemistry, as in German there just aren't any videos which combine theory and "fun" (?) as much as you have with the example of the sumowrestler. Really nice, thank you. (-:

[@basheeranwar9058]

thank you so mush , I hope that you explain more topics that related to the chemical engineering

[@andreac.5596]

Thank you! I knew a little bit about GLC, but never really understood the carrier gas, mobile and stationary phase. I appreciate you so much for explaining this in detail!

[@1987crfe]

This was sooooo easy to understand. Crisp and Clear! Thanks a ton!

[@jamesperry4470]

Good video, but I think it would be good to mention adsorption and why it is a fundamental concept in chromatography and the separation of the mobile phase by their polarity. This would help touch more on the uniqueness of the electron distribution (like if you looked at an electrostatic electron density map) and help communicate how unique each molecule really is when looked at through the means of any system of chromatography

[@J_just_J_yes]

This is a great video, i'm doing a lab report about my gas chromatography and are not sure about what is actually going on for discussion sake's. Now i feel i have a better idea how to explain my data and reason it! Thanks! :) P.S. and the girl's voice is helpful in making sure males(such as myself) are still glued to the video till the end XD

[@Marawan]

this explanation just summed an entire part of my syllabus in only 8 minutes! Brilliant!

[@mithili3906]

Your handwriting is fancy

[@kavitaselvaraj3216]

So informative and easy to understand. Thanks.

[@Simis999]

Such a friendly way of explaining, thanks a lot :)

[@joylynjake4268]

I'm prepared for my chem lab thank you 🙏🏼

[@lovemymonkey05]

I wish I had found your videos when I was still in college.

[@AdilKhan-xv3mh]

That was such a wonderful explanation!

[@arunimachakraborty6423]

I can't thank you enough for this. Bless you. :D

[@ashishtodakar4307]

Arunima Chakraborty I love you

[@maansaab987]

loved your voice

[@Zetarrino]

What about the different polarities of the mobile versus the stationary phase? The substances within the compound that have the opposite polarity of the mobile phase will have traveled slower than the the ones with the same polarity due to attraction/repulsion. Would have liked a little more information about this.

[@easylearning981]

+Zetarrino Hello. Usually, if memory does not fail me, you can NEGLECT intermolecular forces in gas phase for many purposes. So compounds having lower boiling points will just flow within the gaseous inert stream, whilst those with higher boiling points will stay liquid for longer (not necessarily interacting with the liquid stationary phase). What really matters here is that substances with higher boiling points, as long as they stay liquid, will not be able to "flow with the wind", at all. :-) Anyway, I think your question is very worthy. For example, if bigger apolar molecules are mixed with smaller polar molecules. The latter ones were supposed to boil first, but due to interaction with the stationary phase, they do not. Maybe that would invalidate the result somehow.

[@andrewk7470]

"flow with the ... we will never know.

[@bakhodirjonkakhkharov344]

Sal Khan is Elon Musk in education! Thanks for this amazing platform

[@yhpk9013]

Well explain! Thank you so much, I finally can understand the GC.

[@simplestatic3751]

I used the Hewlett Packard 5710a dual-column gas chromatograph with a flame analysation detector.

[@msiloveme16]

Very clear, slow and steady! thanks

[@umawww]

thank god this channel exist

[@prateekgupta3454]

amazing explanation

[@awesomemangoes8072]

Thank you

[@anounymous7988]

You're amazing god bless you 💖💖💖💖

[@seluffhello873]

What if a small compound with high boiling point and a bigger compound with low boiling point is in the mixture? Would that mean that more or less, they would travel at the same rate and will produce only 2 waves in your graph instead of 3?

[@smthgsmthg1717]

Thankyou. You explained very well.

[@rutabnoor4285]

Ahh atlasttt i found you ... Very thankful

[@MsRamy92]

Great video!!

[@cindycho2933]

Very helpful, thanks!

[@prashanthraju4013]

Nice explanation. You said that sample separation in the column ( stationary phase ) is based on the boiling point & molecular size of the solutes present in the mobile phase. Actually it also depends on the polarity also. For example 1. Polar stationary phase & polar mobile phase has more retention time 2. Polar stationary phase & non ploar mobile phase has no interaction so sample in the mobile phase moves faster, lesser retention time. If it's not correct plz ignore my comment. Thanks for ur superrr explaination.

[@charlottebikech]

your voice sounds so much like leighton meester's

[@unknownknown7427]

Superb 👍

[@trevorndhlovu7834]

Fantastic staff my lady it's COOLSOME,I owe you one.

[@demetriosgianitsas9008]

You literally saved my day, great explanation thank you very much!!!

[@lifeofastudent...317]

What if it as similar boiling point and size? How can we distinguish it?

[@guyweizman3791]

Perfect explanation!!!

[@aboodqashoo4113]

And, The affinity is an important factor of separation

[@josyzong7919]

A good video!!! A lot better than my professor. Clear and easy to follow the logic.

[@turkishgamernl8047]

hi, im a student and i have a question about the boiling temperature. why is it that the one with the higher boiling point is going slower and adsorbs better and the other with the lower boiling point is faster and adsorbs badly? is there a reason for or is it just a rule you have to know about gas chromatography?

[@prakharawasthi7062]

more boiling point lesser it will be volatile, it will bind to liquid surface of column

[@agent475816]

+Turkish GamerNL If it has a high boiling point, that means that it prefers to stay as a liquid compared to a gas that has a lesser boiling point.

[@anghaitruyen240]

Would you like to tell me what program you used in your clip?

[@chem-issatwait9528]

Sumo wrestler yeah understood thanks!

[@DuongNguyen-ni9gz]

excellent

[@MadanKumarLakshmanan]

Excellent video. Very clear & informative. Sincere thanks.

[@stephanieme4405]

If my doctor asked for it could he test for my prescription drugs Cymbalta and Lamictal Respridone or and others to make sure I was taking them or to see how much of them was in my system to affect other drugs I was taking?

[@hayaalmly6083]

Thank you! you made it so easier to fathom even for a 7 year old boy!!

[@syamkumar6075]

GasChromatography was explained in a simple manner and in detail covering most of the aspects of GC.

[@obinnaduke]

You're awesome... Thank you so very much

[@digvijayyamagekar7139]

Thank you so much !!! I got the idea now .

[@jenishbarot7171]

thank youuuu......perfect explaination.

[@johngrantner7240]

So good. You kick ass. This made it so much easier to understand

[@sudeepm6484]

what if the difference in the boiling points is not much and the sizes of the molecules of both compounds are also nearly equal? Do the peaks overlap? How to distinguish in such cases?

[@Alicia-dm6yb]

awesome video..very well explained...

[@btslovers9788]

I love your videos. So elaborate!

[@lucyaudrey733]

very nice thank you

[@akram4139]

Thanks so much

[@kingoffunny1747]

Why does it sound like more than one person is speaking?

[@DreadnaughtyArt]

King Of Funny The microphone volume keeps changing.

[@michaelbowe1485]

King Of Funny Multiple personality disorder

[@MightyOwl_01]

+King Of Funny In my classroom ppl are watching without headphones and all i can hear is blah blah blah lol, i cba to get my headphones so i just used subtitles

[@Syeal7]

I think parts of the recording was edited over with additional comments or corrections in which the original "tape" lacked. So the different volumes are actually recorded during different times.

[@omymamohamed29]

Excellent 💜👏

[@mohamedmamdouh4782]

I have one question regarding the temperature of inlet that is around 200 degree then sample is vapourized. After that it is introduced to column via carrier gas. Temperature in oven is ramping starting from might 30 till 220. The question is from high temperature of the inlet to slightly low oven temperature might lead a kind of condensation, how the sample still in vapour state during it 's journey to column. Plz illustrate.

[@MrBlash93]

Great explanation. Thank you for your video

[@xClaireW]

great explanation!

[@enoquemrosa]

phenomenal

[@Lagos08]

Thank you very much for the explanation

[@kennytzz4073]

Thank you!!!! u saved me !!!

[@jitendralodha13]

thanks a lot.

[@dan.6398]

Absolutely great way of expanations. I coudn`t find anything better. Thanks ;)

[@dannytitus1645]

this was really great. Thank you :)

[@samulasaidireddy]

kindly explain of oven track in Gas chromatography

[@aliimadyounis2056]

Thank you ❤️

[@daindelucia7033]

It looks like that, in your graph, time increases toward the origin.

[@mustafabasim684]

Great job

[@AJ-yo7rb]

Really just want to know how to make the “detector”

[@kayleighprice9637]

Thanks again!

[@Agtsmirnoff]

How would the liquid phase stay to the sides?

[@Everyonecallsmesophie]

I love you so much. I really do

[@razo786]

Thanks.

[@IIAmzazZ]

really helpful thanks

[@at8736]

Thank you. My lab TA sucks.

[@Muik69]

Simple and great explanation thanks!

[@eiliannoyes5212]

That's how you do it!

[@shaheenmalick5999]

Does anyone who is taking the MCAT know if Mass Spec will be tested?

[@365messiah]

Great informational

[@bushrayousef8766]

awesome video! thank you :) x

[@josephchong783]

Your voice is amazing

[@boringgrass]

wow nicely explained

[@bartacomuskidd775]

how often does this need to be recalibrated? can a civilian run a GC using only the device manual?

[@crychan]

Bartacomus Kidd in the lab i work in, we run blank standards every 5 or 10 tests to ensure proper calibration and detect outliers

[@Usefulhubofficial]

nice video.like it.

[@minjinoh4998]

Big help

[@azagoodwin5899]

great simplified video ./.... i need more information for which type of substances can we use this technique for? e.g drugs and also what does the height of the peak tells us

[@easylearning981]

+Aza Goodwin The height of the peak informs the intensity. The more molecules reach the detector, higher the peak.

[@prashantprajapati5709]

I have a doubt regarding the separation of the compound, suppose you have 2 compound one is lighter and have high affinity towards the stationary phase and the other compound which is heavier and have low affinity towards the stationary phase and the sample which contains both the compound is run in the gas chromatography then which compound will move out first?

[@Shahram19702010]

That’s why methods development is very crucial. Temperature ramp will resolve your problem.

[@dirfadli2445]

can i ask why they used inert gas to push the gas particles through along the tube

[@uddhavsree]

because you do not want the gas used to push the vapourised particles to react with the latter so as to give 'new' particles. Hence we use an inert gas.

[@ashasety4060]

bcoz to stop the interaction between particles and gas

[@80amnesia]

neat, thumbs up