For detection and quantification of fatty acids GC/GC-MS are normally used. However, analysis of tocopherols, carotenoids, and chlorophylls in vegetable oils can be done by HPLC using RP C30 or Alltima C 18 column with electrochemical array detector or fluorescence detector, Acetonitrile: methanol (50: 50) mixture can be used as a mobile phase. In this process vegetable oils are dissolved in appropriate solvents like methanol: hexane: tetrahydrofuran and the aliquots are injected directly without saponification, thus preventing sample loss or component degradation.
Yes, it is the method for triglycerides analysis in oils.C18 column , acetone/CH3CN phase- you will need a Refraction index detector (best) or an evaporative solvent detetor, About 100mg oil is dissolved in acetone and you inject as usuall. You can see very well the tryglicerides and the free fatty acids.
You can use HPLC-MS-MS to quantify the triglycerides as well as determine isomeric states (ie PPO vs POP). If you are interested in that sort of analysis, Jason Evans at UMass Boston has a couple of papers outlining the details
For detection of drugs stability can I inject drug directly to the hplc device ( Example: I want to detect the effect of temperature on API for Amoxicillin injection solution. My control sample is the drug stored in optimum temperature. Can I inject this control directly to the device or I need to make standard solution. )