1. Interface Engineering Co., Ltd.
Gas Chromatography
-이론과 실제-
2004.
Kim, Wang-Yu Ph.D.
Interface Engineering Co., Ltd.

2. GC의 정의
두개의 상(고정상, 이동상) 사이에서 혼합물 각각의 성분이 분배(혹은 흡착)되는 정도가 다른 성질을 이용하여 각각의 성분을 분리하는 크로마토그래피 기술이다. 이동상으로는 혼합물과 반응하지 않는 기체를 사용하는 것이 HPLC와 크게 다른 점이다.

3. GC vs. LC Mobile phase Gas Liquid Sample state Gas Liquid
Stationary phase
Liquid or solid
Liquid

4. Outside GC

5. Inside GC
Injecting and vaporizing
Detecting
Separating

6. Injection Port
Septum
Graphite ferrule
Inlet liner
Nut

7. Septum

8. Ferrule

9. Capillary columns 1. Stationary phase 2. Inner Diameter(mm)
3. Length(m)
4. Film Thickness(um)

10. FID
Flame Ionization Detector

12. GC Column 종류 (단면) Open (Capillary) Packed Regular Wall Coated
Open Tube
(WCOT)
Conventional
Porous
Bead
Porous Layer
Packed and
Layer
Column
Open Tube
(PLOT)
Micropacked
Bead

13. Capillary Column Types
orous L
ayer O
pen T
ubular (PLOT)
Carrier Gas W
all C
oated O
pen T
ubular (WCOT)
Liquid Phase

14. GC column의 특성 1. Stationary phase 2. Inner Diameter(mm) 3. Length(m)
4. Film Thickness(um)

15. Polarity

16. POLARITY Polarity Solubility Phase = Solute High Phase ¹ Solute Low
High solubility = High retention and capacity

17. DISPERSION INTERACTION Kcal/mole2 4 6 8 10
Benzene
Phenol
C10
C12
8.1
11.9
10.9
DB-1 (non-polar)

18. DIPOLE INTERACTION Compounds With Dipole DifferencesCl H
C=C
C=C Cl Cl H Cl
1,2-dichloroethylene
1,1-dichloroethylene
Smaller differences require a stronger dipole phase

19. HYDROGEN BONDING INTERACTION Example Compounds
Strong: alcohols, carboxylic acids, 1° and 2° amines
Moderate: aldehydes, esters, ketones
Weak: hydrocarbons, halocarbons, ethers

20. SELECTIVITY Interaction Strengths
Phase
Dipersion
Dipole
H Bonding
Methyl
Strong
None
Phenyl
Weak
Cyanopropyl
Moderate
Trifluoropropyl
PEG

21. COMPOUNDS Properties Compounds Polar Aromatic Hydrogen Bonding Dipole
Toluene no
yes
induced
Hexanol
Phenol
Decane
Naphthalene
Dodecane

22. 50% CYANOPROPYL
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12) 2 4 6 8 10 12 14 16
100% Methyl 1 3 5
50% Cyanopropyl
Strong Dispersion Strong Dipole Moderate H Bonding

23. Polysiloxanes (Methyl Substituted)
% = # of sites on silicon atoms occupied
100 % methyl (HP-1, DB-1 etc.)
Nonpolar

24. Polysiloxanes (Phenyl methyl Substituted)
5% phenyl (HP-5, DB-5, etc.) 35% phenyl (HP-35, DB-35, etc.) 50% phenyl (HP-50+, DB-17, etc.)
Nonpolar
Mid-polar
Mid-polar

25. Polysiloxanes (Cyanopropylphenyl methyl Substituted)
6% cyanopropylphenyl (HP-1301, DB-1301, etc.) 14% cyanopropylphenyl (HP-1701, DB-1701etc.) 50% cyanopropylphenyl (HP-225, DB-225, etc.)
Mid-polar
Mid-polar
Polar

26. Two columns are different !!
HP-17: 50% phenyl and 50% methyl siloxane vs HP-50+ : (50%)-Diphenyl (50%)-Dimethylpolysiloxane 3 CH m n Si O CH 3 n Si O
Two columns are different !!

27. Poly(ethylene) GlycolHO -
C-C-O- -H n
100% PEG (HP-WAX)
Less stable than polysiloxanes Unique separation characteristics
Polar

28. POLARITY Solubility And Retention
C12
C10
Hexanol
100% Methyl (non-polar) 2 4 6 8
Same GC conditions
Same column dimensions
Only differ in stationary phase
C10
C12
Hexanol
100% PEG (polar) 2 4 6 8

29. 1. Stationary phase
3. Length(m)
4. Film Thickness(um)
2. Inner Diameter(mm)

30. COLUMN DIAMETER Retention 80°C isothermal
0.25 mm 5 10 15 20
21.81
0.32 mm 2 4 6 8 12 14 16
16.06
Isothermal: Retention is inversely proportional to column diameter Temperature program: 1/3-1/2 of isothermal values

31. COLUMN DIAMETER(0.05~0.53mm) 0.53 mm 0.32 mm n =58,700 n =107,250
Sample capacity : < 2 ug
< 500 ng
Instrumental condition

32. Phase Ratio The combined effect of the column diameter and film
thickness is
described by ,
the
phase
ratio. =
r/2d f
where r =
column
radius ( m) d f =
film
thickness ( m)

33. Differing Column Inner Diameter, Equal Betas
Time
(min) 5 10 15 20
Carrier:
Oven:
65° C
Injection:
Split
Detector:
FID
Column A:
HP-624 B: HP
part
no.
19091V-413 30 m,
0.32
mm,
1.8 m
Helium, 40
(m/sec)
19095V-423
0.53 3

34. 1. Stationary phase
2. Inner Diameter(mm)
4. Film Thickness(um)
3. Length(m)

35. COLUMN LENGTH Theoretical Efficiency
Length (m) N 15
71,430 30
142,860 60
285,720
0.25 mm ID N/m = 4762 (for k = 5)

36. COLUMN LENGTH(10~120m) Resolution and Retention: Isothermal
2.29 min
R=1.16
4.82 min
R=1.68
8.73 min
15 m
30 m
60 m
Double the plates, double the time
but not double the the resolution

37. 1. Stationary phase
2. Inner Diameter(mm)
3. Length(m)
4. Film Thickness(um)

38. FILM THICKNESS(0.1~5um) Retention: Isothermal
7.00
0.25 µm 2 4 6 8
Thermal stability
Sample b.p.
25.00
1.00 µm 5 10 15 20 25

39. More stationary phase = More degradation products
FILM THICKNESS Bleed
More stationary phase = More degradation products

40. “Back biting” Mechanism of Bleed FormationSi HO
H3C
CH3
CH3 Si O OH
CH3 OH Si O
CH3 + Si O
CH3
H3C
Again

41. Four Types Of Low Bleed Phases
Phases tailored to “mimic” currently existing polymers
-Examples: DB-5ms, DB-35ms, DB-17ms
New phases unrelated to any previously existing polymers
-Example: DB-XLB
Optimized manufacturing processes
-Example: DB-1ms

42. Column Installation Choosing ferrule Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning

43. Ferrule Graphite(100%) - 450℃ - general purpose and reused
Choosing ferrule
Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Ferrule
Graphite(100%)
- 450℃
- general purpose and reused
- FID, NPD, ECD
- Not good for Mass
Vespel(100%)
- 280℃
- reused
- for only isothermal operation

44. Choosing ferrule
Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Cutting
Jagged silica edges or exposed polyimide cause adsorption and tailing peaks, so it is very important that the column ends are cut uniformly.

45. Inlet installation 먼저 column nut를 capillary column에 끼우고 ferrule을 끼운다.
Choosing ferrule
Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Inlet installation
먼저 column nut를 capillary column에 끼우고 ferrule을 끼운다.
3cm 이상 capillary가 나오게 한 후 먼저 inlet에 조여 capillary가 ferrule에 적당히 물리게 한다.
일단 푼다.
capillary를 5mm정도 남겨놓고 자른다.
다시 inlet에 연결한다.
손으로 꽉 조인 상태에서 ¼~반바퀴 더 wrench로 돌린다.
이동상을 흘렸을 때 이 부분에 Leak가 있을 경우 injector 압력 gauge가 올라가지 않는다.

46. Leak-checking Use acetone in vial Choosing ferrule
Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Leak-checking
Use acetone in vial

47. Choosing ferrule
Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Outlet installation
보통 detector jet orifice보다 1-3mm 아래쪽에 column end가 있게 한다(보통 capillary를 detector안쪽으로 끝까지 밀어 넣어 넣은 후 2mm정도 뒤로 뺀다).
column nut와 ferrule을 끼우는 요령은 inlet과 같다.

48. Carrier gas Flow Choosing ferrule Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Carrier gas Flow

49. Conditioning 40℃ start and 5~10℃/min below 20~25℃ Choosing ferrule
Cutting the capillary column
Inlet installation
Leak-checking
Outlet installation
Establishing flow
Conditioning
Conditioning
40℃ start and 5~10℃/min
below 20~25℃

50. Storage septum on each end of the column
Especially for PEG type column

52. Split/Splitless Injection

53. Splitless Injection

54. And Now Let’s do Some
TROUBLESHOOTING

55. DB-624 COLUMN QC Test Mix Column: DB-624 1. 1,2-Dichloropropane
2.71
Column: DB-624
30m x 53mm I.D., 3.0µm
Carrier: Helium at 40 cm/sec
measured at 35°C
Injector: Mega Direct, 260°C
Detector: FID, 300°C
Oven: °C for 1.50 min
30°/min to 65° for 10 min
1. 1,2-Dichloropropane
2. Octane
3. Tetrachloroethylene
4. Chlorobenzene
5. Nonane
8.0e4
7.0e4
6.0e4
7.43
10.92
5.0e4
4.0e4
17.42
12.49
3.0e4
20.78
2.0e4
1.0e4 5 10 15 20 25
Time (min.)

56. Example of Column Contamination
2.21
1.5e4
1.4e4
DB-624 QC Test Mix*
After 75 Injections of Oily Sample
1.3e4
3.30
1.2e4
1.1e4
1.0e4
6.03
9000
9.26
8000
10.46
7000
14.40
17.86
6000 5 10 15 20
Time (min.)

57. Column and Liner Contamination
Inlet coil of column

58. Example of Column Contamination
2.80
1.2e4
1.1e4
Removed 1 1/2 m from injector end *
1.0e4
7.34
9000
10.79
8000
17.19
12.33
7000
20.56
6000
5000 5 10
Time (min.) 15 20 25

59. Backflush Column Rinse with 10ml each:
Methanol, Methylene Chloride, Hexane
Capillary column
Special connector and ferrule
Flexible teflon tubing
1/16" flexible teflon line to regulated pressure source
Special adapter
Cap
Vial
Beaker for solvent collection
Capillary column

60. Remember Complete system = Carrier Gas + Injector +
Column + Detector + Data System
Multiple cause and effect
Do not change too many variables at once