QUADRUPOLE

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QUADRUPOLE

Рет қаралды 119,878

Dr. David Kreller Chemistry

Күн бұрын

Conceptual explanation of the way a Quadrupole Mass Filter works.

Пікірлер: 35

@bratwurst5267 10 жыл бұрын

Thank you for the video! Very helpful. At the end around 10:44 you should swap the description "do pass" and "do not pass" because like this it looks like a small window of m/z does not pass. But this is a small mistake in an otherwise very helpful video.

@dkreller01 11 жыл бұрын

Yes, I will admit that the explanation is perhaps a bit too qualitative. When I posted I was expecting that there was a weakness there. However, I had a good time trying to explain this, and I am glad if this video helped you in your studies.

@davidmirander7415 8 жыл бұрын

Thank you very much. I didn't understand the alternating voltages before this, and now I understand the mass requirements for each set of quadrupoles.

@lisaghosh3966 4 жыл бұрын

Excellent! Very informative. 👍👍

@simonagidova8856 5 жыл бұрын

Thank you from all videos about quadrupole this is the best for understanding😊😊helped much

@lorenzwirth 8 жыл бұрын

Thank you very much! Nicely explained, I finally understood.

@sammyk1155 4 жыл бұрын

Very nice video Dr Keller, very helpful

@zhongpingliao3574 9 жыл бұрын

Very helpful vedio for understanding how DCand RF is used to select ions by the four rods. The only mistakes the m/z selection of the two dimentions (X, Y) should be overlapped in order to have a narrow m/z pass through the rods. Otherwise, no ion will pass through.

@TheFormigalformigal 8 жыл бұрын

There is a mistake in the graph at 10:30. The Y edge is wrong. The label "Do pass" should be "Don't pass" and vice versa.

@haubentaucher8382 4 жыл бұрын

As far as I understand the X-dimensions switch should be shifted more to thr right and the Y-dimensions more to the left, so there is a small overlap. Flipping one of the dimensions would render the flipped one meaningless.

@codchemistryclub4358 4 жыл бұрын

No, it is correct as written. There are two voltages applied, + and -. Ions that are small WILL pass the first, (so their line is high), but they stop passing at a certain point (drops to the baseline). Large m/z will NOT pass the -DC rods, so they are at baseline (do not pass) and shoot up to "do pass" for +DC. The gap in the middle is the range of m/z of ions that will pass BOTH. The lines only represent the sizes that do or not pass each step. the correct size ions would be a 3rd color, at the top I suppose. The idea is to highlight the narrow window of sizes that will work, not show a line for them.

@neeleshukla 9 жыл бұрын

Very helpful in understanding the working principle of quadrupole.

@parniunplugged7023 7 жыл бұрын

very nice explanation for beginners.. Thank you very much

@prapsdy 7 жыл бұрын

at 11:34... shouldn't the do pass lines overlap? red line fitler is barring all the molecules that green line filter is allowing and vice versa.

@apiitg 3 жыл бұрын

You are correct. There is a mistake in that graph. They should have a narrow overlap for m/z to pass.

@Huangbeibei 2 жыл бұрын

I agree

@DP-vm2dd Жыл бұрын

hi! at 4:04 the potential should not start from 0, because the radiofrequence voltage is V* (cos freq. *t). So it should start with a positive value. is it ri ght?

@29Valle12 7 жыл бұрын

thanks!I found it very helpful and clear

@MrElectricSkittles 8 жыл бұрын

excellent finishing diagram

@matteopiccioni196 4 жыл бұрын

Great explation..but how can a rod produce both a sinusoidal and constant potential?I also saw the electrical configuration of the genertors..but I'm used to think about than electrons flux are in movement or stationary....it is killing my mind

@sammyk1155 4 жыл бұрын

A DC voltage and an ac voltage are combined together. So if the DC is say +1 volt and the ac is 1 volt peak to peak it would be like the ac wave was raised 1 volt on the graph, so y=sin(X) becomes y=sin(X) + 1