This document discusses the use of gas chromatography techniques for food analysis. It provides examples of analyzing various compounds in different food products, such as determining propionic acid in bread, antioxidants in chewing gum, pesticide residues, and contaminants in foods. It also discusses the analysis of fats, fatty acids, amino acids, and carbohydrates in foods. Various detectors that can be used are mentioned, such as FID, ECD, NPD, and MS. Methods for rapidly screening drugs and analyzing pollutants in water are also summarized.

1. Gas Chromatography Technique
for Food Analysis
Abhijit Bhar

2. Determination of PCBs in Waste Oil – parallel on FID and ECD

3. PCBs DETERMINATION
ECD - Electron Capture Detector

4. Components in Food with high Carbohydrates
Determination of Propionic Acid in Bread
Determination of Antioxidants in Chewing gum
2,6-di-(dimethylethyl)-4-methylyphenol (BHT)
2-and 3-dimethylethyl-4-hydroxyanisole isomers (BHA)
Determination of artificial flavors in chewing gum
Determination of natural thickening agent
Determination of Ergot Alkaloids in Cereal products (cause sever
poisoning on human body)
Determination of Ethyl Carbamate in Alcoholic Beverages
Determination of β-Asarone in Alcoholic Beverages
Determination of Halogenated acids in Beer and Wine products
Determination of Diethylene Glycol in Wine

6. Fats and Compounds in Fat containing Foods
Fatty Acid Composition
Erucic Acid, a characteristic compoudn in fats of Brasicacea species
Butyric Acid (should be within 3.6%)
Determination of Organic acids in Egg powder (Succinic acid indicates the
hygininc conditions of egg, β-hydroxybutyric acid indicates fertilized egg). Both
kind of detrioration are accompanied by an increase in the concentration of
lactic acid
Determination of artificial flavor
Determination of Cholesterol in egg products
Determination of Sterols and Steryl Ester
Identification of brominated vegetable oil IBVOs are additives used in citus-
based beverages to disperse the flavoring oils)

8. Orange flavored soft drink containing BVOs

9. TMS derivatives of Amino Acids

10. FAME
Fast analysis
FAME mixture
Column DN WAX - 10 m x 0.1 mm x 0.2 mm
PTV Injector 50°C – 600°C/min to 400°C (2 min)
Oven 40°C (0.5 min) - 30°C/min to 90°C –
70°/min to 130°C - 10°C/min to
250°C (2 min)
Carrier gas flow rate 0.5 mL/min (H2)
Split ratio 1:40
FID detector 350°C
Digital Acq Rate 100 Hz
Injection Volume 0.5 mL
Fast GC separation of FAME (10 mg/mL) mixture.
FID - Flame Ionization Detector

11. Carbohydrates and related compounds – Disacharide TMS derivatives

12. Carbohydrates and related compounds – Trisacharide TMS derivatives

13. Caramel Colors – using Dani Pyroliser Curie point
Caramel colours are brown food colourings,
produces by heating sugars in the presence of
browning accelerators. On this basis of accelerators
used, the following of caramel colours are
recognised:
Class I : CP Caramel colour (Plain), Spirit caramel,
non-aroma caramel
Class II : CCS Caramel colour (Caustic Sulphite
Process)
Class III : AC Ammonia Caramel Colour, Beer
Caramel
Class IV : SAC Sulphite Ammonia Caramel, Soft
drink Caramel, Acid Proof Caramel

14. Analysis of Residues and contaminants
Pesticide Residues
Contaminants
Adulteration

16. Resolution
R=1.249
Resolution
R=1.995
DN – 5
30min.
5min.
NITROGEN/PHOSPHOROUS
Pesticides MIX (DN 5
separation)
Dichlorvos, EPTC, butylate,
mevinphos, vernolate, pebulate,
tebuthiuron, molinate,
propachlor, cycloate, trifluralin,
chlorpropham, atraton,
ethoprop, atrazine, propazine,
pronamide, terbacil, simetryn,
alachlor, ametryn, prometryn,
terbutryn, methyl, paraoxon,
chlorpyriphos, cyanazine,
tetrachlorvinphos, bromacil,
metolachlor, triadimefon, MGK-
264, diphenamid, butachlor,
napropamide, tricyclazole,
norflurazon, hexazinone,
fenarimol, fluridone.
GC Conditions
Oven: 100°C, 40°C/min., 290°C Inj: SL/IN
300°C
Det: NPD 300°C Carrier: He 0.5 ml/min
Split: 50ml/min
Sensitivity S/N = 270
0,05 ppm split 1:50
MDL= 0.5 ppb
Acquisition = 250 Hz
Determination of Nitrogen/Phosphorous Pesticides
using FAST NPD Detector
NPD - Nitrogen-Phosphorous Detector

17. Pesticide in baby food
0.2ppm each, Total run time 3 min

18. Mass spectrum OPP

19. Mass spectrum OPP

20. Rapid drug screening
12 drugs in 5 min, resolution is excellent

21. Brominated flame retardant in water

22. Chlorinated VOCs in Water – no sample preparation
Purging
for Liquid matrices
Applications
1
2
3
4
5
6
7 8 9
10 + 11
12
13
14
15
16
17
18
19
22
20 + 21
23 26
24 + 25
27
28
29
30 + 31
32
33
34
35
36
37
1
2
3
4
5
6
7 8 9
10 + 11
12
13
14
15
16
17
18
19
22
20 + 21
23 26
24 + 25
27
28
29
30 + 31
32
33
34
35
36
37

23. Applications
EPA 502.2
Compounds MDL (ppb) RSD% MDL (ppb) RSD%
1 1,1 Dichloroethylene 0.01 1.5 0.07 2.8
2 Methylene choride 0.002 2.0 0.02 2.9
3 trans-1,2-Dichloroethylene 0.03 3.0 0.06 3.7
4 1,1-Dichloroethane 0.003 2.2 0.07 5.7
5 2,2-Dichloropropane 0.005 1.1 0.05 3.4
6 cis-1,2-Dichloroethylene 0.01 16.6 0.01 3.3
7 Chloroform 0.0005 0.8 0.02 2.5
8 Bromochloromethane 0.0005 0.8 0.01 3.0
9 1,1,1-Trichloroethane 0.0005 0.9 0.03 3.3
10 1,1-Dichloropropylene 0.0003 0.7 0.02 3.3
11 Carbon tetrachloride 0.0003 0.7 0.01 3.6
12 1,2-Dichloroethane 0.002 0.5 0.03 3.8
13 Trichloroethylene 0.0005 1.2 0.01 3.6
14 1,2-Dichloropropane 0.002 1.3 0.01 3.7
Chlorinated VOCs in Water

24. Applications
EPA 502.2
Compounds MDL (ppb) RSD% MDL (ppb) RSD%
15 Bromodichloromethane 0.0003 0.8 0.02 2.9
16 Dibromomethane 0.0003 1.6 0.02 1.5
17 cis-1,3-Dichloropropylene 0.0007 2.0 0.06 3.7
18 trans-1,3-Dichloropropylene 0.001 1.6 0.01 33.7
19 1,1,2-Trichloroethane 0.0014 1.5 N.D. 5.6
20 1,3-Dichloropropane 0.0004 0.7 0.03 3.1
21 Tetrachloroethylene 0.0004 0.7 0.04 2.5
22 Dibromochloromethane 0.0003 0.5 0.8 2.8
23 1,2-Dibromoethane 0.0005 0.9 2.2 6.7
24 Chlorobenzene 0.0003 0.9 0.01 3.6
25 1,1,1,2-Tetrachloroethane 0.0003 0.9 0.01 2.3
26 Bromoform 0.0005 1.0 1.6 5.2
27 1,1,2,2-Tetrachloroethane 0.0007 1.6 0.01 6.8
28 1,2,3-Trichloropropane 0.0025 0.8 0.4 2.3
Chlorinated VOCs in Water

25. Applications
EPA 502.2
Compounds MDL (ppb) RSD% MDL (ppb) RSD%
29 Bromobenzene 0.012 1.6 0.03 2.7
30 2-Chlorotoluene 0.002 3.3 0.01 2.7
31 4-Chlorotoluene 0.002 3.3 0.01 3.2
32 1,3-Dichlorobenzene 0.007 0.2 0.02 4.0
33 1,4-Dichlorobenzene 0.018 3.4 0.01 2.3
34 1,2-Dichlorobenzene 0.01 3.0 0.02 1.5
35 1,2-Dibromo-3-chloropropane 0.005 4.0 3.0 11.3
36 1,2,4-Trichlorobenzene 0.004 2.8 0.03 2.1
37 1,2,3-Trichlorobenzene 0.0012 2.5 0.03 3.1
The high sensitivity of the system confirmed the applicability of
the Dynamic Headspace sampler operated in purging mode
Chlorinated VOCs in Water

26. Aromatic VOCs in Water – No sample preparation
Applications

27. Aromatic VOCs in Water
Compounds MDL (ppb) RSD%
1 Benzene 0.12 2.0
2 Toluene 0.12 2.1
3 Ethylbenzene 0.13 2.6
4 m-Xylene 0.09 7.9
5 p-Xylene 0.09 7.9
6 o-Xylene 0.15 4.0
7 Styrene 0.16 1.5
8 Isopropylbenzene 0.25 1.7
9 n-Propylbenzene 0.25 2.4
10 Bromobenzene 0.32 0.9
11 1,3,5-Trimethylbenzene 0.19 0.3
12 2-Chlorotoluene 0.2 4.7
13 4-Chlorotoluene 0.2 1.0
14 tert-Butylbenzene 0.24 1.2
15 1,2,4-Trimethylbenzylene 0.18 0.5
16 sec-Butylbenzene 0.3 0.1
17 4-Isopropyltoluene 0.3 5.0
18 1,3-Dichlorobenzene 0.4 1.8
19 1,4-Dichlorobenzene 0.4 1.4
20 n-Butylbenzene 0.6 2.8
21 1,2-Dichlorobenzene 0.4 2.9
MASTER DHS
Sample Volume 10 mL
Trap Material Tenax/ Carbotrap/Carbosieve
Operating Mode Purging Mode
Valve Temp. 250 °C
Transfer Line Temp. 250 °C
Incubation Temp. 60 °C
Stripping Time 3 min
Stripping Flow 120 mL/min
Trap Stripping Temp. -10 °C
Injection Time 3 min
Trap Injection Temp. 295 °C
Dew Stop Temp. 0 °C
Baking Time 10 min
Trap Baking Temp. 300 °C
Dew Stop Baking Temp. 200 °C
Baking Flow 80 mL/min
MASTER GC
Column Vocol (Supelco)
60 m x 0.32 mm, 3 mm
Oven 35 °C (8 min) at 4 °C/min to
240 °C (1 min)
Injector SL/IN (220 °C)
Carrier Gas Flow (He) 3.5 mL/min (split 1:2)
Detector FID (250 °C)

28. Applications
DHS
Flavour Profile in Parmesan Cheese

29. Acids and Aroma in Alcoholic beverages

30. Butyl Acetate in Milk, cheese,Black
Tea, Vinegar, Honey, etc
• Colourless
• Flammable with fruity
odour
• In water or under
influence of light slowly
decompose to acetic
acid and their
respective alcohols

31. Total Profile by GC-TOF

32. Dairy Milk – Solvent traces
Capsicum flavor – Parle G

33. Analysis of pyrazines (flavour compounds) in crisps

34. Contaminants???? Or Adulteration???
Edible oil Contaminated by Animal Fat
- Presence of C14 in more quantity indicates mixing of Coconut oil/Palm
kernel/Butter
-Presence of C16 in more quantity indicates coconut oil/Palm/Butter/Lard/Beef
tallow
- From the ratio of Pametic, Stearic, Linoleic we can find out the adulteration of
Animal fat with plant oil
Adulteration can be determined by GC by analyzing Fatty Acid composition
Presence of solvents can be demined by GC with Headspace

35. DHS-GC-TOF

36. RELIABLE AND ENHANCED RESULTS
FOR A VARIETY OF APPLICATIONS
PACKAGING
Determination of residual solvents in
food packaging
Important to know the source – food or food packaging!!!!!!!

37. GCxGC TOF for higher HC
• Standard GC-MS does not provide
the resolving power required to
analyze very complex mixture of
petroleum. GCMS chromatograms
usually comprise a characteristic
‘hump’ of matrix material, meaning
compound peaks are only partially
resolved.
• Confident sample characterization,
i.e. compound identification,
depends on full mass spectra
acquisition of full mass spectra,
including molecular and fragment
ions, over a wide range of volatility
(C10-40 and higher)

38. Power of GCxGC
• GCxGC is an important
technique to the petroleum
industry as the additional
dimension allows better
separation of very complex
mixtures, meaning minor
components previously
hidden in the large
background matrix can be
seen. High data records,
1000 spectra /sec provides
high sensitivity and classical
spectral data, allow accurate
compound identification.

39. • Dani Master GCxGC TOF with DN-1, 30mt x 0.25mm ID x 0.25 micron FT, DN-50,
2mt. X 0.1mm ID x 0.1 micron FT

40. PAHs standard mixture
1 Naphthalene
2 1-methylnaphthalene
3 2-methylnaphthalene
4 Acenaphthylene
5 Acenaphthene
6 Fluorene
7 Phenanthrene
8 Anthracene
9 Fluoranthene
10 Pyrene
11 Benzo(a)anthracene
12 Chrysene
13 Benzo(b)fluoranthene
14 Benzo(k)fluoranthene
15 Benzo(a)pyrene
16 3-methylcholanthrene
17 Indeno(1,2,3-c,d)pyrene
18 Dibenzo(a,h)anthracene
19 Benzo(g,h,i)perylene
PAH std mix (20 ppb each) in
Hexane
Precolumn: 5 m x 0.32 mm id
1D Column: RTX5 30 m x 0.32 mm id
2D Column: BPX-50 0.8m x 0.1 mm id
Modulation time 4s
1 2 3
4 5 6
7
8
9
10
11
12
13
15
14
16
17
18
19
Solvent Peak 3.4 min

41. PAH
Acenaphthene
2 ppb
S/N = 27
Fluorene
3.2 ppb
S/N = 55
Naphthalene
9 ppb
S/N = 140
PAHs in Composite Diesel Fuel
Injected 30mL

42. Pesticide analysis with TOF & 2D
1
2
3
4 6
7
8
5
9
11
12
10
Tomato Extract Spiked with a
Pesticides Mixture (15 - 50 ppb)
Precolumn: 5 m x 0.32 mm id
1D Column: RTX5 30 m x 0.32 mm id, 0.25 µm
2D Column: BPX-50 1 m x 0.1 mm id, 0.1 µm
Modulation time 5s
Captan
35 ppb
Folpet
22 ppb
Vamidothion
47 ppb
Component ppb
1) Dichlorvos 27
2) Mevinphos 27
3) Dimethoate 48
4) Carbaryl 37
5) Pirimiphos 45
6) Captan 35
7) Folpet 22
8) Bromophos 51
9) Vamidothion 47
10) Celathion 33
11) Captafol 28
12) Azinphos 15