2.8. Derivatization procedure
To a solution containing a standard fatty acid mixture or sample in a 2 mL vial, 100 mL derivatization reagent solution, 10 mg K
and 100 mL DMF were added. The vial was sealed and allowed to react in a water bath at 90 1C for 30 min. The derivatization procedure is shown in Fig. 1. After the reaction was completed, the mixture was cooled to room temperature, then an appropriate volume of acetonitrile solution was added to dilute the derivatization solution to 0.6 mL. The diluted solution was syringe filtered using a 0.22 mm nylon filter and injected directly for HPLC analysis (10 mL).