A new high pressure liquid chromatography–electrospray ionization–t
andem mass spectrometry method for the simultaneous determination of
glucosinolates, as glucoraphanin
and glucoerucin,
and the corresponding
isothiocyanates, as sulforaphane
and erucin, was developed
and applied to quantify these compounds in
Eruca sativa defatted seed meals
and enriched functional foods. The method involved solvent extraction, separation was achieved in gradient mode using water with 0.5% formic acid
and acetonitrile with 0.5% formic acid
and using a reverse phase C18 column. The electrospray ion source operated in negative
and positive mode for the detection of
glucosinolates and isothiocyanates, respectively,
and the multiple reaction monitoring (MRM) was selected as acquisition mode. The method was validated following the ICH guidelines. Replicate experiments demonstrated a good accuracy (bias% < 10%)
and precision (CV% < 10%). Detection limits
and quantification limits are in the range of 1–400 ng/mL for each analytes. Calibration curves were validated on concentration ranges from 0.05 to 50 μg/mL.
The method proved to be suitable for glucosinolates and isothiocyanates determination both in biomasses and in complex matrices such as food products enriched with glucosinolates, or nutraceutical bakery products.
In addition, the developed method was applied to the simultaneous determination of glucosinolates and isothiocyanates in bakery product enriched with glucosinolates, to evaluate their thermal stability after different industrial processes from cultivation phases to consumer processing.