After confirming the possibility to perform modulation using MS-compatible flow conditions and demonstrating the chromatog- raphy benefits of using a longer accumulation loop, an FM GC × LP GC–qMS method was developed for the analysis of a very complex FAME mixture, namely menhaden fish oil. While the GC1 and GC2 columns were the same, other operational conditions were mod- ified (see Method II, Section 2.2). In particular, the temperature program was set at a higher initial temperature (150◦C) because the menhaden fish oil FAMEs are characterized by higher boiling points compared to milk FAMEs; additionally, a slower tempera- ture gradient (1.5◦C) was applied to enable the separation of as many as possible compounds on the polyethylene glycol dimen- sion.