Die Präsentation wird geladen. Bitte warten

Die Präsentation wird geladen. Bitte warten

TFH 2005 WS Chromatographie Abhängigkeit der Trennleistung eines chromatographischen Systems von Geschwindigkeit der mobilen Phase Van Deemter.

Ähnliche Präsentationen


Präsentation zum Thema: "TFH 2005 WS Chromatographie Abhängigkeit der Trennleistung eines chromatographischen Systems von Geschwindigkeit der mobilen Phase Van Deemter."—  Präsentation transkript:

1 TFH 2005 WS Chromatographie Abhängigkeit der Trennleistung eines chromatographischen Systems von Geschwindigkeit der mobilen Phase Van Deemter

2 TFH 2005 WS

3 Eddy-Diffusion A Peakform kurz nach der Injektion Peakform nach Passieren des Säulenbettes

4 TFH 2005 WS Diffusion B Peakform kurz nach der Injektion Peakform nach Passieren der Säule

5 TFH 2005 WS Stoffaustausch C Veränderung der Peakform durch den Stoffaustausch- Prozess

6 TFH 2005 WS

7

8 Open Tubular Columns At a constant pressure Flow rate is proportional to cross sectional area Flow rate is inversely proportional to the column length For open tubular column this means that we can get Increased linear flow rate and/or a longer column Decreased Plate height, which means improved better resolution

9 TFH 2005 WS Gas Chromatography

10 TFH 2005 WS

11

12 C-Term

13 TFH 2005 WS

14 Mass Transport Band Spreading

15 TFH 2005 WS Asymmetric Bands

16 TFH 2005 WS Comparison of open tubular and packed columns. Open tube columns –Higher resolution –Shorter Analysis time –Increased sensitivity –Lower sample capacity

17 TFH 2005 WS 2D - GC

18 TFH 2005 WS

19 Modulators Thermal modulator Cryogenic modulator

20 TFH 2005 WS

21

22 Comprehensive GC Auch GC x GC oder multidimensional GC. 1. Trennung auf normaler Säule. 2. Trennung auf kurzer microbore Säule. Gesamtes Effluenz der 1. Säule wird in sehr viele Fraktionen aufgeteilt und auf die 2. Säule gegeben. Resultierendes Chromatogramm hat zwei Zeitachsen (die Retentionszeiten der beiden Säulen) trapping und Reinjektion durch Modulator bewirken Fraktionsfokussierung.

23 TFH 2005 WS Gas Chromatography

24 TFH 2005 WS Gas Chromatography

25 TFH 2005 WS Gas Chromatography

26 TFH 2005 WS Residual Solvents - ICH Topic Q3C

27 TFH 2005 WS HPLC - Gas Chromatography

28 TFH 2005 WS Shes a reversed-phase gradient HPLC This is Ursula

29 TFH 2005 WS HPLC Injector port guard column LOAD / INJECT

30 TFH 2005 WS Alltech 450 UV Detector (254nm fixed)

31 TFH 2005 WS Time needed for one cycle: 55 min GC HP 6890 SAMPLER HS / OC Multistage temperature program HP MSD This is Pat It is a GC-MS

32 TFH 2005 WS Plate THEORY

33 TFH 2005 WS HETP = h In distillation, Actual plates exist whhere vapour passes through a liquid phase During this mixing, equilibrium between the phases is assumed The height of a plate can often be directly measured In a packed column or a capillary the plates can´t be observed – called theoretical plates Plate theory

34 TFH 2005 WS Typical Plate Heights GC ~ 0.1 to 1 mm[30 m] HPLC ~ 0.01 mm[0,25 m] CZE ~ mm[0,1 m]

35 TFH 2005 WS The Peak Ideal chromatographic peaks are Gaussian in peak shape. This comes directly from the Craig Model. We know certain facts about Gaussian peaks.

36 TFH 2005 WS Parameter aus Chromatogramm Gaussform angenommen k`= t´ R / t R

37 TFH 2005 WS Plate theory Partition coefficient k´ Solute fractions: mobile phase:1 / (1+ k´) stationary phase:k´/ (1+ k´) ß = r c /2d f 1 = 1 / (1+ k´) + k´/ (1+ k´)

38 TFH 2005 WS

39 Alltechs Heliflex® AT-1ht GC capillary column is designed for the analysis of samples containing high boiling compounds and high molecular weight samples. The phase ratio of a column ( ) is equal to the radius of the column divided by twice the film thickness. A higher allows for the elution of high molecular weight samples in a reasonable time; or the elution of medium molecular weight samples at low temperatures. By keeping the temperatures low, the column bleed is also kept to a minimum. Phase Ratio: =r/2df ID df K = k` x ß k`= K / ß

40 TFH 2005 WS

41 Heat as a separations tool.

42 TFH 2005 WS

43 We could potentially measure the width at half height and knowing it is a Gaussian peak derive the following.

44 TFH 2005 WS Resolution = t r / w ave = t r /w 1/2 ave

45 TFH 2005 WS Factors Affecting Resolution k`= K / ß

46 TFH 2005 WS

47

48 Oberflächenchemie

49 TFH 2005 WS Cross section of a Fused Silica Column Open Tubular

50 TFH 2005 WS HTS

51 TFH 2005 WS PHASEN

52 TFH 2005 WS Choosing the Bonded Phase

53 TFH 2005 WS Choosing the Bonded Phase R = C 14 alkyl R1 = isopropyl shielding Diisopropyl side groups provide steric protection against low p H Triple endcapping, shielding PG = polar amide group Polar amide group embedded in a long alkyl chain reduces interactiions between basic analytes and silica support


Herunterladen ppt "TFH 2005 WS Chromatographie Abhängigkeit der Trennleistung eines chromatographischen Systems von Geschwindigkeit der mobilen Phase Van Deemter."

Ähnliche Präsentationen


Google-Anzeigen