Introducing GC/MS into the Undergraduate Organic Lab Dan Blanchard, Ph.D. Kutztown University http://faculty.kutztown.edu/blanchar/

GC/MS as an Organic Tool Goals of Organic Lab Characterization Logistics Challenges Experiments Conclusions

Goals of Organic Laboratory at KU Learn Laboratory Techniques Carry Out Organic Syntheses Explore Chemistry of Everyday Life Demonstrate Concepts from Lecture Most Involve Synthesis or Isolation

Importance of Characterization Synthesis Routine React Isolate Purify CHARACTERIZE Isolation Routine Isolate Purify CHARACTERIZE

Characterization Traditionally Melting Range GC/MS Not related to structure Sample purity dependence Not modern techniqe GC/MS Can be introduced early at basic level Can be developed across the course Modern technique

GC/MS – Logistics Should students operate the instrument in the Organic lab? One Solution: The Autosampler Allows for more samples and longer run times Students can enter their own information. Students should get to operate the instrument once.

Challenges of Introducing GC/MS Introducing two techniques at once Two graphs for one run! Heaviest ion versus most abundant ion Fragmentation: multiple simultaneous reactions

Identification of Volatile Flavor Components by Headspace Analysis Simple sample preparation Short run times Identification is made by molar mass alone limonene, ethyl butyrate, benzaldehyde, isoamyl acetate Drawback: Not all candies have adequate volatile components Kjonaas, R.A.; Soller, J.L.; McCoy L.A., J. Chem. Educ. 1997, 74, 1104-1105.

Isolation of the Active Ingredients from Cough Syrup Includes acid-base extraction Example of combining traditional concept with GC/MS Sherren, A. T. Presented at The American Chemical Society National Meeting, Boston, MA, 1999.

Fatty Acids Present in Snack Foods Isolation of oils from potato chips Detection of prepared FAMES No MS interpretation Food for discussion Rubinson, J.F.; Neyer-Hilvert, J., J. Chem. Educ. 1997, 74, 1106-1107.

Grignard Synthesis of an Unknown C6-C9 Alcohol Unknown alkyl halide plus unknown ketone Product is characterized by IR, 13C NMR, GC/MS NO molecular ion Fragmentation analysis is required Everett, T.S., J. Chem. Educ. 1998, 75, 86-87.

Also Adopted Isolation of Essential Oils from various spices Pavia, D.L.; Lampman, G.M.; Kriz, G.S.; Engel, R.G. Introduction to Organic Laboratory Techniques, A Microscale Approach, Third Edition; Saunders: Philadelphia, 1999; pp 487-492. Chlorination Reactivity Ratios for Methylcyclohexane Bishop, R.D., Jr., J. Chem. Educ. 1995, 72, 743-745.

Also Modified Acetylation of Ferrocene Amenta, D.S.; DeVore, T.C.; Gallaher, T.N.; Zook, C.M.; Mosbo, J.A., J. Chem. Educ. 1996, 73, 572-575.

Also Tried Preparation of a C-4 or C-5 Acetate Ester Pavia, D.L.; Lampman, G.M.; Kriz, G.S.; Engel, R.G. Introduction to Organic Laboratory Techniques, A Microscale Approach, Third Edition; Saunders: Philadelphia, 1999; pp 472-475. McGoran E.C.; Melton, C.; Taitch, D., J. Chem. Educ. 1996, 73, 88-92

Conclusions There exist a wide range of experiments which already incorporate GC/MS. There are a wide range of experiments which can be modified to incorporate GC/MS. GC/MS is a modern structurally-based characterization technique that can be introduced early in the organic course and developed across both semesters.

Acknowledgements National Science Foundation, Division of Undergraduate Education Organic lab students at KU 1999-2004 Colleagues and lab instructors at KU 1999-2004

References Kjonaas, R.A.; Soller, J.L.; McCoy L.A., J. Chem. Educ. 1997, 74, 1104-1105. Sherren, A. T. Presented at The American Chemical Society National Meeting, Boston, MA, 1999. Rubinson, J.F.; Neyer-Hilvert, J., J. Chem. Educ. 1997, 74, 1106-1107. Everett, T.S., J. Chem. Educ. 1998, 75, 86-87. Pavia, D.L.; Lampman, G.M.; Kriz, G.S.; Engel, R.G. Introduction to Organic Laboratory Techniques, A Microscale Approach, Third Edition; Saunders: Philadelphia, 1999; pp 487-492. Amenta, D.S.; DeVore, T.C.; Gallaher, T.N.; Zook, C.M.; Mosbo, J.A., J. Chem. Educ. 1996, 73, 572-575. Bishop, R.D., Jr., J. Chem. Educ. 1995, 72, 743-745. Pavia, D.L.; Lampman, G.M.; Kriz, G.S.; Engel, R.G. Introduction to Organic Laboratory Techniques, A Microscale Approach, Third Edition; Saunders: Philadelphia, 1999; pp 472-475. McGoran E.C.; Melton, C.; Taitch, D., J. Chem. Educ. 1996, 73, 88-92