escence at a particular wavelength. Subsequent analysis by a chiral HPLC results in
the separation ofsn-1,2 andsn-2,3 diastereomers (Itabashi and Takagi, 1987; Takagi
and Ando, 1990; Christie et al., 1991; Uzawa et al., 1993; Kim et al., 1994; Chandler
et al., 1998). In the case of sTAG containing PUFA, it may be unnecessary for en-
antiomeric DAGs to be converted into the diastereomeric derivatives because the
DAGs have an absorption at 206 nm; thus they can be directly detected spectropho-
tometrically.
9.2.6 High-temperature gas chromatography (HTGC)
For analyzing the reaction mixture of sTAG synthesis by gas chromatography (GC),
precaution should be taken against instability of PUFA at elevated temperature. On-
column injection (Traitler, 1988) is the best technique for transferring a sample con-
9.2 Monitoring the reaction 157
Figure 3. Gas chromatogram of the reaction mixture [see Equation (1)] (Han et al., 1999a). Peak 1,
solvent; 2, C8EE; 3, caprylic acid; 4, internal standard (n-eicosane); 5, EPAEE; 6, dicaprylin; 7, trica-
prylin; 8, DAG; 9, TAG-A; 10, TAG-B.