Light and heavy dansyl reporter groups in food chemistry: amino acid assay in beverages.
5-Dimethylamino-1-sulfonyl naphthalene (DNS, commonly referred as dansyl) is a functionality, bearing well-established properties in directing the fragmentation, by mass spectrometry (MS), of the corresponding ionized sulfonylated derivatives. This property is shared also by its labeled analogs. The use of d(0)/d(6) DNS derivatives is now exploited in the application of the well-established isotope dilution mass spectrometric approach in the assay of complex mixtures. A new method for the quantitation of amino acids (AAs) in beverages is therefore presented, which relies on liquid chromatographic separation of their N-dansylated derivatives followed by comparative electrospray tandem MS/MS of the d(0)/d(6) isobaric mixtures. Labeled and unlabeled DNS derivatives of the selected AAs are readily available by microwave-assisted synthetic protocols. The novelty of the method is represented by the use of heavy and light DNS-isotopologue providing suitable reporter groups. Multiple-reaction monitoring has been applied in the assay of AAs in wine, pineapple juice and bergamot juice with good-to-excellent results as proved by both relative standard deviation, lower than 15%, and by the accuracy values in the range 90-110%.
Dipartimento di Chimica, Università della Calabria, Via P. Bucci Cubo 12/C, I-87036, Arcavacata di Rende, Cosenza, Italy.
Fabio
F
Mazzotti
Hicham
H
Benabdelkamel
Leonardo
L
Di Donna
Constantinos M
CM
Athanassopoulos
Anna
A
Napoli
Giovanni
G
Sindona
D000596:Amino Acids / Q000032:analysis / Q000737:chemistry*; D001628:Beverages / Q000032:analysis*; D003619:Dansyl Compounds / Q000032:analysis / Q000737:chemistry*; D003903:Deuterium / Q000032:analysis / Q000737:chemistry; D005504:Food Analysis / Q000379:methods; D005638:Fruit / Q000737:chemistry; D007553:Isotope Labeling; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods; D014920:Wine / Q000032:analysis
D000596:Amino Acids; D003619:Dansyl Compounds; D003903:Deuterium; C029038:dansyl chloride