After experimentally demonstrating that the use of gas flows in the 6–8 mL/min range can produce efficient modulation, the next research objective was to extend the concept of very fast LP GC to the field of GC × GC. The initial intention was to use a 10 m × 0.53 mm ID column, because such capillaries have been proven to work ideally under such gas flow conditions A 1.5 m × 0.25 mm ID restrictor was positioned before the analytical column to avoid sub-ambient pressure conditions reaching the wafer chip. The accumulation loop dimensions were 20 cm × 0.51 mm ID. Initial optimization applications were carried out on a single compound, namely C10 n-alkane. Under the experimental conditions applied (see Method I in Section 2.2), the He average linear velocity (ALV) in the first dimension was 12.9 cm/s (initial flow: 0.44 mL/min). During the accumulation period (2.7 s), the loop ALV was 3.7 cm/s. With regard to the injection pulse (0.4 s), the flow exiting the modulator was calculated to be about 7 mL/min, while the second-dimension ALV was ∼170 cm/s. In short, both ideal very-fast LP GC and MS-compatible gas flow (the maximum qMS pumping capacity was 15 mL/min) conditions were used. Three modulated peaks relative to the C10 n-alkane are shown in Fig. 1a. Apparently, the modulation process worked well.