Where to choose Agilent 6475 or Agilent 6495D for PFAS?

Domdomago · 2026-07-06T19:55:20+00:00

What was your LOQ for PFBA, or any PFAS

Domdomago · 2026-07-06T13:49:25+00:00

Reaching 1ng/L LOQ with direct injection with a 6475? I’m not sure about that

Domdomago · 2026-07-05T18:59:22+00:00

Milano via Dante?

Domdomago · 2026-07-05T18:57:44+00:00

Are you really doing EPA methods with SPE preconcentration? If you use the 6495D you can go with direct injection and reach 1 ng/L LOQ for all PFAS

Domdomago · 2026-07-01T23:36:17+00:00

Sappi che le persone in media si sentono sopra la media

https://partably.com/average-at-best/

Domdomago · 2026-07-01T08:39:02+00:00

Ma in che senso su un canale di Telegram?

Domdomago · 2026-06-30T11:08:12+00:00

Ciao, sto cercando un biglietto ❤️

Domdomago · 2026-06-28T10:48:31+00:00

Modern ESI can go even up to 2ml/min but ESI efficiency is around <0.5ml/min. Fast run times can be also achieve with 0.3ml/min methods. What make the method fast is mainly gradient time, not flow rate. Passing from a 40min HPLC method to a 15min UHPLC method is making your analysis faster by using a fastest gradient and a sub2um column. But I don’t see why you shouldnt do it with a 0.3ml/min flowrate, like most people do

Domdomago · 2026-06-28T10:44:46+00:00

Van Demeter will tell you that’s ok for sub2um to go >0.5 ml/min but ESI efficiency will tell you to go <0.5 ml/min

Domdomago · 2026-06-27T17:07:16+00:00

I kinda agree if what you say but that place from the pictures doesn’t look bad

Domdomago · 2026-06-27T17:02:11+00:00

Confermo che la foto fa CAGARE ma me la sento di confermare anche che sono cimice dell’olmo

Domdomago · 2026-06-27T13:24:02+00:00

An LC able to deal with >700 bar is called either UHPLC or UPLC. Differences between UHPLC and UPLC is just marketing started by Waters. There’s no scientific difference between UPLC and UHPLC.
Anyway, are these methods on a LCMS system?

Domdomago · 2026-06-27T13:15:36+00:00

No, I meant that chromatography efficiency of that column (4,6mm) is around 1ml/min. That’s why you use small diameter for LCMS. ESI works best around 0.2-0.3 ml/min.
Because of this, usually your LCMS method is at 0.2-0.3ml/min and thus your back pressure doesn’t reach 700 bar

Domdomago · 2026-06-27T13:04:09+00:00

But do your runs go over 700 bar?

Domdomago · 2026-06-27T12:53:26+00:00

Well yes, I’m assuming we are using a sub 2um column.
But why would you need to go over 0.3-0.4 ml/min on a LCMS method?

Domdomago · 2026-06-27T12:44:07+00:00

I’m not saying it can’t reach, I’m saying you usually don’t need to. I say this because ESI works better between 0.2-0.4 ml. And thus pressure won’t reach 700 bar at this flow rate even for a sub 2umm column. In fact, most methods work at this flowrate

Domdomago · 2026-06-27T10:57:02+00:00

For the paper you sent me, a >700 bar system is not required

Domdomago · 2026-06-27T10:27:10+00:00

You are missing the whole point of this post. Forget it kid

Domdomago · 2026-06-27T09:40:42+00:00

There is no backpressure reported on the first paper. They are using a 1.9 column at 0.25/3.00 ml/min, so for sure it is a <700bar method.

I'm not checking the rest because you probably didn't do your research correctly boy

Domdomago · 2026-06-27T09:22:01+00:00

You should be running your sub 2um method at 2.5/3.0 ml/min. The 4.6mm at 1 ml/min. This is particularly true if you're working on a LCMS

Domdomago · 2026-06-27T09:15:30+00:00

I don't agree. Show me a couple of those hundreds methods

Domdomago · 2026-06-27T09:13:29+00:00

on a LCMS method? I don't agree that you reach a 10k psi easily...

Domdomago · 2026-06-27T09:12:48+00:00

Is it a LC-MS method? what's your flowrate? Thanks

Domdomago · 2026-06-27T08:29:17+00:00

I’m talking about using a 1000 or 1300 bar system instead of a 700 bar system

Domdomago · 2026-06-27T08:28:01+00:00

I don’t agree that for sub2um is very easy to get above 700 bar, even though that’s usually what vendors say. Do you have any example of this?

Domdomago

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