Questions to think about:

What is a lipid?
Where are lipids found?
How can lipids from plant oils, adipose fats, and dairy products be distinguished?
Milk fat residue analysis is specific application of compound-specific stable isotope mass spectrometry. How does it work?
What are some limitations of this method? What assumptions are being made (and possibly violated). Consider in particular human behavior with respect to cooking methods and utensil use.