1. The Fatty Acid Content of
Shrimp Shell Chitin
Jessie Moravek
Northwestern University 2016

2. What is chitin?
Biopolymer found in
arthropod
exoskeletons and
fungal cell walls

3. What is chitin?
Biopolymer found in
arthropod
exoskeletons and
fungal cell walls
What are Fatty
Acids?
Long chains of
carbon and
hydrogenC16 Fatty Acid

4. Evidence of
Fatty Acids in
fossilized chitin
PreservationofChitinin25-Million-Year-OldFossilsAuthor(s):B.ArthurStankiewiczetal.
Created by
fossilization
process?
Already
associated
with chitin?
Where did
these fatty
acids come
from?
Fossilized insect
Fossil SEM image

5. Experimental Outline
Part 1:
Extraction and
analysis of fatty acids
in shrimp shells
Part 2:
Purification of shrimp
shell chitin and
analysis of fatty acids
in the purified chitin
Are fatty acids naturally associated with chitin?

6. Methods, Part 1:
Shrimp Shells
Dry/Powder Shells
Organic Solvent Extraction
TMAH-Pyr-GC-MS:
Identify/Quantify Fatty Acids
Normalize Fatty Acids to stable
chitin derivative
Shells
Organic Extraction
GC-MS

7. Unextracted Shell Extracted Shell
Remaining Fatty Acids: Shell
Sample
peakarearatio(FA/ChitinDerivative)
051015

8. 9.5 10.0 10.5 11.0 11.5 12.0
0510152025
Retention Time (min)
RelativePeakIntensity Chromatogram: Shrimp Shell, post-extraction
Chitin
Derivative
C16 Fatty Acid
C18 Fatty Acid

9. Methods, Part 2:
Purified Chitin
Methansulfonic Acid:
Dissolve, Filter, Re-Precipitate
Organic Solvent Extraction
TMAH-Pyr-GC-MS:
Identify/Quantify Fatty Acids
Normalize Fatty Acids to stable
chitin derivative
GC-MS
Purified
Chitin
Shells
Compare to chitin standard

10. 9.5 10.0 10.5 11.0 11.5 12.0
020406080100
Retention Time (min)
RelativePeakIntensity
Chitin
Derivative
C16 Fatty Acid
C18 Fatty Acid
Chromatogram: Purified Chitin

11. 9.5 10.0 10.5 11.0 11.5 12.0
020406080100
Retention Time (min)
RelativePeakIntensity Chromatogram: Purified and Standard Chitin
Purified Chitin
Chitin Standard
Chitin
Derivative
C16 Fatty Acid
C18 Fatty Acid

12. Unextracted Shell Extracted Shell Purified Chitin
Remaining Fatty Acids: Shell and Purified Chitin
Sample
peakarearatio(FA/ChitinDerivative)
051015

13. Evidence of
Fatty Acids in
fossilized chitin
PreservationofChitinin25-Million-Year-OldFossilsAuthor(s):B.ArthurStankiewiczetal.
Created by
fossilization
process?
Already
associated
with chitin?
Where did
these fatty
acids come
from?
Fossilized insect
Fossil SEM image

14. Conclusions
• Fatty acids remained in purified chitin after
purification from shrimp shells
• Suggests fatty acids may be naturally associated
with chitin
• Thus: Fatty acids potentially associated with chitin
prior to fossilization

15. Future Studies
•Investigate association between chitin and fatty acids
• Physical association?
• Covalent bond?

16. Acknowledgements
•Neal Blair
•Laurel Childress
•Kathryn Schreiner
•Northwestern University
Office of Undergraduate Research

17. TMAH-Pyr-GC-MS
Tetramethyl Ammonium Hydroxide

18. Organic Solvent Extraction
• Solvent = 9:1 Dichloromethane and Methanol
• Microwave extraction
• Filter out sample
• Dry

19. Methansulfonic Acid purification procedure
• Dissolve shell in acid
• Filter out minerals/proteins
• Add filtrate to ice water to re-precipitate chitin
• Centrifuge chitin
• Rinse and dry

20. Chitin (blue) vs. Shell (red)
9.5 10.0 10.5 11.0 11.5 12.0
0e+002e+084e+086e+08
Retention Time (min)
PeakIntensity
Purified Chitin
Shell

21. Atmosphere
Land Biota
and Soils
Oceans
Lithosphere Coal, Oil, Gas
The
Carbon
Cycle