High resolution mass approaches for wine and oenological products analysis

Transcription

1 High resolution mass approaches for wine and oenological products analysis Barnaba C., Nardin T., Larcher R. IASMA Fondazione Edmund Mach, via E. Mach, 1, San Michele all Adige, Italy

2 High resolution mass analysis Over 2,400 studies on LC-HRMS in the last 20 years; Almost 50% of them on Orbitrap. Main topic clinic and forensic toxicology omic sciences food safety and control environmental pollution

3 High resolution mass analysis Non-targeted (NO reference standard) Suspect (NO reference standard) Targeted analysis (reference standard) Suspect ions list Targeted ions list Automated peak detection by exact mass filtering Exact mass (m/z) filtering Exact mass (m/z) filtering Non-targeted ions list Generation of elemental formulae fit by isotopic pattern distribution Molecular structure search in databases Matching of measured RT with predicted RT (theoretical logk ow ) of databse hits Matching of measured MS/MS fragmentation with that predicted for database hits Matching of measured RT with predicted RT(theoretical logk ow ) of suspects Matching of measured MS/MS fragmentation with that predicted for suspects Matching of measured RT with RT of reference standards Matching of measured MS/MS fragmentation with that of reference standards List of likely present unknowns List of likely present suspects Quantification of targets

4 High resolution mass analysis Non-targeted (NO reference standard) Absence of any a priori information about analytes; Detection criteria (e.g. product scan or NL); Automated peak detection by exact mass filtering Non-targeted ions list Mass accuracy: < 5 ppm; Relative isotopic ratio accuracy: < 5%; Generation of elemental formulae fit by isotopic pattern distribution Molecular structure search in databases Matching of measured RT with predicted RT (theoretical logk ow ) of database hits Matching of measured MS/MS fragmentation with that predicted for database hits Reduced number of recorded experimental spectra; Limited comparability of different source ionization; Ion suppression can affect mass accuracy and number of unknows; Risk of false negatives (e.g. loss during sample preparation). List of likely present unknowns

5 High resolution mass analysis Suspect (NO reference standard) Suspect ions list Exact mass (m/z) filtering Absence of reference standards, but specific information available; Exact mass from molecular formula of analytes of interest; Mass accuracy: < 5 ppm; Relative isotopic ratio accuracy: < 5%; Reduced number of recorded experimental spectra; Matching of measured RT with predicted RT(theoretical logk ow ) of suspects Matching of measured MS/MS fragmentation with that predicted for suspects Limited comparability of different source ionization; Ion suppression can affect mass accuracy and number of suspects; Risk of false negatives. List of likely present suspects

6 High resolution mass analysis Targeted analysis (reference standard) Targeted ions list Exact mass (m/z) filtering Identification and quantification through reference standards; No limits in the number of targeted compounds to be identified in the same analytical run; No risks of false negative thanks to method validation with reference standards; Mass accuracy: < 5 ppm; Matching of measured RT with RT of reference standards Relative isotopic ratio accuracy: < 5%; Matching of measured MS/MS fragmentation with that of reference standards Quantification of targets

7 HRMS applications International monovarietal wines Glycosidic profiling Non-targeted Tannins Glycosylated lowmolecular-weight Suspect Targeted analysis Free low-molecularweight phenolic enrichment Oak agedwines Free and glycosylated lowmolecular-weight Grapes & wines

8 HRMS applications International monovarietal wines Glycosidic profiling Non-targeted Tannins Glycosylated lowmolecular-weight Suspect Targeted analysis Free low-molecularweight phenolic enrichment Oak agedwines Free and glycosylated lowmolecular-weight Grapes & wines

9 Non-targeted analysis Glycosides Sugar esters Z = Glycosylation: - Increases compound water solubility; - Protects hydroxyl/phenolic groups from oxidation; - Decreases toxicity of phitotoxins; - Facilitates compound membrane transports; -

10 Neutral Loss experiment Chromatographic separation Accucore Polar Premium LC C18 Flow rate: ml/min; Run time: 55 min. Mass analysis Full MS/AIF/NL dd-ms 2 Full MS resolving power: 140,000 FWHM; AIF and dd- MS/MS resolving power: 17,500 FWHM; NEUTRAL LOSS (Δm/z = 10 ppm) m/z m/z m/z m/z m/z m/z

11 Neutral Loss experiment: tentative identification 282 glycosylated compounds detected: 149 Unknowns 133 glycosides tentatively identified 9 hexose esters

12 HRMS applications International monovarietal wines Glycosidic profiling Non-targeted Tannins Glycosylated lowmolecular-weight Suspect Targeted analysis Free low-molecularweight phenolic enrichment Oak agedwines Free and glycosylated lowmolecular-weight Grapes & wines

13 Suspect & targeted analysis Free low-molecular weight phenolic compounds (N=56) Compounds [M H] - RT LOQ NCE MS/MS fragments (m/z) (min) (µg ml -1 Compounds [M H] - LOQ (m/z) RT (min) NCE MS/MS fragments ) (µg ml -1 ) gallic acid acetovanillone+isoacetovanillone , protocatechuic acid isopropiosiringone , p -carboxyphenol acid acetosyringone , gentisic acid , isoacetosiringone , hydroxytyrosol , syringol , vanillic acid , coniferylaldehyde syringic acid , sinapinaldehyde , caffeic acid tryptophol , homovanillic acid , o -vanillina , tyrosol , methyl vanillate , protocatechuic aldehyde , (m +p )-cresol , pirocatecolo , ethylcatechol p -coumaric acid , o -cresol salicylic acid , vanillyl ethyl ether , phenol guaiacol , catechin , methylsyringol , ferulic acid , vinylphenol , aesculetin , ethyl vanillate , sinapinic acid , xylenol , homovanillic alcohol , vinylguaiacol , epicatechin , ellagic acid , vanillin , ethylphenol , coniferyl alcohol , methylguaiacol methylcatechol , ethylguaiacol , syringaldehyde , allyl syringol , isopropiovanillone , eugenol scopoletin , isoeugenol , Glycosylated low-molecular weight phenolic compounds (N=7) Barnaba et al., J. Chromatography A (2015), 1423, Compounds [M H] - (m/z) RT (min) NCE MS/MS fragments (µg ml -1 ) acetovanillone-glu (h) ; aesculetin-glu (b) ; orcinol-glu (f) ; p -hydroxybenzaldehyde-all (f) ; salicylic acid-glu (f) ; scopoletin-glucoside (h) ; vanillic acid-glucoside (h) ; LOQ

14 HRMS applications International monovarietal wines Glycosidic profiling Non-targeted Tannins Glycosylated lowmolecular-weight Suspect Targeted analysis Free low-molecularweight phenolic enrichment Oak agedwines Free and glycosylated lowmolecular-weight Grapes & wines

15 Suspect & targeted analysis: grapes Hybrid grape varieties Cabernet Cantor Prior Solaris Muscaris Vitis vinifera grape varieties Barnaba et al., Food Res. Intern. (2017), in press. Merlot Chardonnay

16 Suspect & targeted analysis: wines Primitivo di Manduria (DOP); Negroamaro (IGP). Primitivo di Manduria Negroamaro months in French and American oak barrels Barnaba et al., Food Chem (2016), 206,

17 HRMS applications International monovarietal wines Glycosidic profiling Non-targeted Tannins Glycosylated lowmolecular-weight Suspect Targeted analysis Free low-molecularweight phenolic enrichment Oak agedwines Free and glycosylated lowmolecular-weight Grapes & wines

18 Targeted analysis: oak-aged wines Pressurized cold water (NT) Chemical treatment (KOH) (CT) Ozone (OT) Wines were oak-aged Guzzon et al., J. Food Sci. Technol (2017), 54, for 97 days

19 HRMS applications International monovarietal wines Glycosidic profiling Non-targeted Tannins Glycosylated lowmolecular-weight Suspect Targeted analysis Free low-molecularweight phenolic enrichment Oak agedwines Free and glycosylated lowmolecular-weight Grapes & wines

20 Suspect analysis: tannins

21 Suspect analysis: tannins 169 glycosylated low-molecular weight phenolic compounds tentatively identified:

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