A cross-plot (Figure ) of replicate bulk and compound specific isotope ratio measurements (Table ) shows good agreement between  13 C values for two synthetic standards, tripalmitolein and apolane-87, even where apolane-87 was eluted at 430°C GC oven temperature. The mean compound specific  13 C value of intact tripalmitolein (-27.11 ‰ ±0.08 ‰; n = 3; Table ) was not significantly different (student's t-test, p = 0.18) from the bulk  13 C isotope value obtained for the neat TAG (-27.31 ‰ ±0.20 ‰; n = 3; Table ). Bulk tripalmitolein measurements were obtained using 0.25 mg samples (191 µg C; C = 76.45% of TAG) whereas the CSIRMS measurements were obtained with either approximately 10 or 20 ng of TAG (~ 7.6 or 15.3 ng C) injected on column and tripalmitolein eluting at 390°C (e.g. Figure ). Similarly, the mean CSIRMS  13 C isotope value (-32.39 ‰ ±0.42 ‰; n = 4; Table ; 43 ng C on column) of apolane-87, which eluted at 430°C (e.g. Figure ), was not statistically different (student's t-test, p = 0.43) from the bulk  13 C isotope value obtained for apolane-87 (-32.61 ‰ ±0.07 ‰; n = 3; 214 µg C; Table ). High temperature gas chromatography can be used to characterise the distribution of TAGs in different vegetable oils (Figure ). However, the heterogeneity of TAGs between different olive oil brands is less obvious (Figure ) and isotope ratio techniques could be usefully applied. Using bulk analysis of olive oil samples OIL2 (-28.29‰ ±0.17‰, n = 3; Figure ) and Oil 8 (-28.76‰ ±0.12‰; n = 3; Figure ) it was possible to statistically differentiate these samples based on their 13 C isotope ratios.