Table 4.

Comparison of glycidyl ester measurements in five oils using direct LC–MS method and double SPE method

Sample/method	Glycidyl laurate	Glycidyl myristate	Glycidyl palmitate	Glycidyl stearate	Glycidyl oleate	Glycidyl linoleate	Glycidyl linolenate
	Sample conc. (ng/g)
LOQ (ng/g)	200	200	200	600	300	200	300
RBWD corn
Direct LC–MS
Mean	<LOQ	<LOQ	240	<LOQ	504	1,069	<LOQ
Std dev			5		17	12
CV			2.0%		3.3%	1.1%
Double SPE
Mean	<LOQ	<LOQ	212	<LOQ	565	960	<LOQ
Std dev			22		19	71
CV			10.1%		3.3%	7.4%
RBWD canola
Direct LC–MS
Mean	<LOQ	<LOQ	<LOQ	<LOQ	1,320	643	<LOQ
Std dev					42	26
CV					3.2%	4.0%
Double SPE
Mean	<LOQ	<LOQ	<LOQ	<LOQ	1,598	477	<LOQ
Std dev					71	37
CV					4.5%	7.7%
RBD mid oleic sunflower
Direct LC–MS
Mean	<LOQ	<LOQ	<LOQ	<LOQ	579	461	<LOQ
Std dev					24	22
CV					4.2%	4.7%
Double SPE
Mean	<LOQ	<LOQ	<LOQ	<LOQ	641	326	<LOQ
Std dev					33	21
CV					5.1%	6.5%
RB soy
Direct LC–MS
Mean	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	262	<LOQ
Std dev						19
CV						7.3%
Double SPE
Mean	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ
Std dev
CV
RBD palm
Direct LC–MS
Mean	<LOQ	<LOQ	2,870	<LOQ	5,641	1,963	<LOQ
Std dev			89		261	75
CV			3.1%		4.6%	3.8%
Double SPE
Mean	<LOQ	<LOQ	1,905	<LOQ	4,374	1,015	<LOQ
Std dev			131		304	108
CV			6.9%		7.0%	10.6%

Three replicates of each method were included