The F-2-1 cluster is a quaternary alkylammonium salt with characteristics similar to those of the E-1 cluster. However, when the E-1 cluster was trimethyl, the F-2-1 cluster had three or four long alkyl chains and the peak derived from CH2 was particularly strong in the fingerprint region. The F-2-2-1-1 cluster was a long alkyl chain containing an ester or tertiary amine, with characteristic CH peaks at approximately 3000, 1500, and 700 cm -1 , which were very similar to those of G cluster. However, the background of the fingerprint area was smaller than that of the G-1 cluster and larger than that of the G-2 cluster, and it was determined to be a separate group. The F-2-2-1-2-2-2-2-2-1 cluster is a saturated hydrocarbon that is highly similar to those in the E and G clusters and contains inorganic compounds, as measured using the Nujol method. The major difference observed between clusters E and G is the flat top of the 3000 cm -1 peak. The F-2-2-2 cluster did not exhibit any particular similarity, except for the CH-derived peak near 3000 cm -1 , with only the sides of the peaks in the fingerprint region overlapping each other.