Summary
Samenvatting - GC & HPLC
- Course
- Institution
Samenvatting d.m.v. aantekeningen per les
[Show more]
Seller
Follow
sannevveldhoven
Content preview
Gaschromatografie & HPLCSamenvatting
,Les 1
Retentietijd
Retentietijd = tijd die nodig is om een opgeloste stof te elueren tr = tm + t’r
Tr = (bruto) retentietijd
Tm = tijd van een onvertraagd component
= tijd van verblijf in de mobiele fase componenten die worden vertraag
T’r = netto retentietijd = tijd van verblijf in de stationaire fase
Retentiefactor voorheen capaciteitsfactor
Resolutie (scheiding)
Resolutie wordt bepaald door:
o Afstand tussen de pieken (tr)
o Breedte vd pieken (w)
Goede scheiding als:
o Δtr groot is
o W klein is
Voor kwantitatieve bepaling: Rs > 1,5
Rekenen met schotels, formules toepassen
( ) ( )
2 2
tr tr
o Theoretical plates: N=16 =5,545
wh wh
Lc
o Plate height: HETP=H=
N
o HETP: Theoretische schotelhoogte: "Height of a Theoretical Plate".
Schotels bij LC column
1000∗l
o Voor totaal poreuze kolom geldt theoretisch: N=
2∗dp
1000∗l
o In de praktijk: N=
2,5∗dp
o l lengte kolom in mm
o dp deeltjes grootte in micrometer
o
, Parameter Gegevens chromatogram Formule
Capaciteitsfactor k tr en tm
t r ' t r−tm
k= =
tm tm
Selectiviteit α tr en tm
t'r2 k2
α= =
t'r1 k1
[ ]
Schotelgetal N tr en σ 2
FWHM = 2.35σ tr
FWBP = 4σ N=16∗
FWBP
[ ]
2
tr
N=5,545∗
FWHM
Resolutie Rs tr en σ
∆tr (tr 2−tr 1)
Rs= = ¿¿
W
( tr 2−tr 1)
Rs=
0,85∗(FWHM 1+ FWHM 2)
Rekenen aan het chromatogram
Retentiemechanisme
o Adsorptie GSC
o normal phase
o Verdeling GLC
o reversed phase
o Elektrostatisch interactie
o Ion – exchange
o Moleculaire zeefwerking
o Biologische affiniteit
pKa / log p
o pH < pKa zuur neutral, base positief geladen
o log p < 1 polair
o 1< log p < 3 matig polair
o Log p > 3 apolair
Type chromatografie
Reversed phase
- Stationaire fase = apolair
- Mobiele fase = polair
- Veel gebruikte basis-eluens: water, eventueel met bufferzouten en/of
andere hulstoffen
- Veel gebruikte modifiers: methanol, acetonitril
Normal phase
o Stationaire fase = polair
o Mobiele fase = apolair
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller sannevveldhoven. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.03. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75057 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now