Enhanced aroma profiling of wine by

GC–TOF MS with variable-energy ionisation

38th ISCC & 11th GCxGC, Riva Del Garda

Markes International – vendor seminar

Laura McGregor1, Luca Calamai2,3 Steve Smith1 and Nick Bukowski1

1. Markes International, Gwaun Elai Medi-Science Campus, Llantrisant, RCT, UK

2. Centro Interdipartimentale di Servizi di Spettrometria di Massa, Via U. Shiff 6, 50016 Sesto Fiorentino , (FIrenze)

3. Dip. Scienze delle Prod. Agroalimentari e dell’ambiente (DISPAA), Univ. degli studi di Firenze, Piazzale Cascine 28,

50144 Firenze

Wine aroma is a complex combination of a wide

number of simple sensory perceptions

What gives wine it’s characteristic aroma is...

Source: zinfandel.org

… A combination of many different volatile compounds typical of each wine

Off odours

Approaches for characterising wine aroma

Sensory vs. Analytical

Source: www.arcus.no

sensitivity

Major Drawbacks

Major Advantages

sensitivityreproducibility

Uses sensory descriptors and their intensity as assessed by

Use compounds identification and quantification by

reproducibility

Panel test (5-30 members)HS–(GC)–MS analysis

Analytical approach for studying wine aroma Headspace–SPME sampling

15 min

1 mL wine 4 mL water

2 g NaCl40 uL ISTD mix

60 ºC

DVB/carboxen/PDMS fiber (50/30 µm).

GC–TOF MS

BenchTOF-Select:Data rate: 4 HzMass range: 30–450 amuIon source: 200 ºCTransfer line: 260 ºCIonisation energy: variable

GC Oven:40 ºC for 1.0 min,2 ºC/min to 60 ºC3 ºC/min to 150 ºC10 ºC/min to 200 ºC 25 ºC/min to 250 ºC (hold 10 min).

Column: HP-Innowax (50 m × 200 µm × 0.4 µm)Injection:Splitless, 260 ºC.

Quantitative approach: Calibration Standard mix

• The calibration standard mix spanned a wide range of target compounds prepared in same way as for wine aroma profiling (SPME) but using a 12% ethanol solution containing 0.5% tararic acid as a wine mimic matrix instead of 1mL of wine

• Target compounds from 5 chemical classes:

– Esters

– Lactones

– Aldehydes & Ketones

– Alcohols & Terpene alcohols

– Acids

• Internal Standard compounds: two deuterium-labelled compounds or surrogate absent in samples for each class

Results

Calibration standard with wine mimic matrix

Ethyl acetate

Isoamylacetate

2-methyl-1-propanol

Isoamylalcohol

Ethyl hexanoate

Hexyl acetate

Hexanol

Ethyl octanoate

Benzaldehyde

Decanoicacid

Ethyl

decanoate

Octanoicacid

The full presentation can be downloaded from the Markes websitehttp://www.markes.com/Resources/Scientific-publications/Conference-presentations.aspx

Conclusions

• Low energy ionisation aids identification and extends LoDs

• Low energy ionisation aids identification and extends LoDs

• 70 eV and 14 eV give comparable quantitative results

• GC×GC allows additional compounds to be identified

– Off-odours

– Fungicides

– Compounds at ultra-trace level

Case study 2:

Enhanced screening of environmental pollutants in complex matrices by GC××××GC–TOF MS

A collaboration with…

Water Framework Directive (WFD)

• Lower detection limits

• New monitoring methods and analytical techniques are now necessary

• Focus is on “priority” substances, but what about those of emerging concern?

Conclusions & Further Work

• Promising start to the project; Select-eV adds an extra dimension of information

• Quantitation of POPs required

• Compare local drinking water/pollution levels with prosthesis extracts

Acknowledgements

• Anthony Gravell (NRW), Ian Allan (NIVA) and

Graham Mills (Portsmouth Uni)

• N. Bukowski, G. Davies, D. Barden and S. Smith,

Markes International

• Luca Calamai, University of Florence

The full presentation can be downloaded from the Markes websitehttp://www.markes.com/Resources/Scientific-publications/Conference-presentations.aspx

Contact Markes…

www.markes.comenquiries@markes.com