3.1. Validation of lipase hydrolysis
To verify that the lipase acted only
on 3-MCPD esters, three controls were used.
The comparison of lipase action on
3-MCPD and lipase action on 3-MCPD
esters, the comparison of
lipase action on 3-MCPD esters and
lipase no action on 3-MCPD esters,
the comparison of
pure
solution of 3-MCPD, lipase action on 3-MCPD and pure solution of lipase.
As seen in the chromatogram, comparison between the effect of lipase on
3-MCPD and the effect of lipase on 3-MCPD esters (Fig. 1), the peak
time, mass spectrogram information and ratio in qualitative ion map of
the two were similar, indicating that the same substance was finally
obtained, that is, the enzymatic hydrolysis was successful.
Comparison between the effect of lipase action on
3-MCPD esters and lipase no action
on 3-MCPD esters (Fig. 2).
3-MCPD
is produced by the action of lipase on 3-MCPD ester, but the lipase does
not act on the 3-MCPD ester does not produce the 3-MCPD, and 10.705 min
is peak time of 3-MCPD esters. This indicated that the enzymatic
hydrolysis was successful.
Comparison among pure solution of 3-MCPD, lipase action on 3-MCPD and
pure solution of lipase (Fig. 3).
The comparison of the three results shows that, the response of pure
solution of 3-MCPD and lipase action on 3-MCPD is almost the same.
However, the pure solution of lipase
do not produce 3-MCPD peak, indicating that the lipase can not act on
3-MCPD. Therefore, 3-MCPD produced by lipase action on 3-MCPD esters is
successful, and has nothing to do with the addition of 3-MCPD internal
standard during the experiment.
3.2 Selection of