PMID- 18377916
OWN - NLM
STAT- MEDLINE
DCOM- 20080813
LR  - 20090115
IS  - 0021-9673 (Print)
IS  - 0021-9673 (Linking)
VI  - 1190
IP  - 1-2
DP  - 2008 May 9
TI  - Quantitative analysis of 3-alkyl-2-methoxypyrazines in juice and wine using 
      stable isotope labelled internal standard assay.
PG  - 294-301
LID - 10.1016/j.chroma.2008.02.088 [doi]
AB  - A solid phase microextraction (HS-SPME)-GC-MS methodology was established for the 
      analysis of 3-alkyl-2-methoxypyrazines (MPs) in wine using a stable isotope 
      dilution assay. The compounds analysed were 3-isobutyl-2-methoxypyrazine (IBMP), 
      3-sec-butyl-2-methoxypyrazine (SBMP), and 3-isopropyl-2-methoxypyrazine (IPMP) 
      using their respective deuterated analogues ([2H3]-IBMP, [2H3]-SBMP, [2H3]-IPMP) 
      as internal standards, synthesised during this work. A 
      divinylbenzene/carboxene/polydimethylsiloxane (DVB/CAR/PDMS) fibre was selected 
      for isolation of MPs and the effects of matrix parameters such as pH and ethanol 
      concentration were examined in the development of the method. Best results were 
      obtained at a pH of approximately 6 and with a wine dilution factor of 1:2.5, 
      resulting in an ethanol concentration of approximately 5% (v/v). Relative 
      standard deviations (RSDs) of replicate samples were 5.6-7% for all MPs at 5 ng 
      L(-1) and <5% for 15 and 30 ng L(-1) samples. The limit of detection was <0.5 ng 
      L(-1) in juice and 1-2 ng L(-1) in wine. The recovery efficiencies for spiked 
      wine samples were between 99 and 102% for all three MPs. Using this method, we 
      investigated the impact of the Multicoloured Asian Lady Beetle (MALB) on MPs in 
      wine. In red wine fermented with live MALB, IPMP is the most prevalent MP 
      detected, although SBMP concentrations are also increased and IBMP is unchanged 
      from background levels. MALB that have been dead for 1 day before addition to 
      juice can still contribute to elevated SBMP concentrations in wine, but not if 
      they have been dead for 3 days or longer. Clarifying juice prior to fermentation 
      leads to substantially lower IPMP concentration in the subsequent wine when 
      compared with unclarified juice.
FAU - Kotseridis, Y S
AU  - Kotseridis YS
AD  - Department of Food Science & Technology, Agricultural University of Athens, 
      Athens, Greece. ykotseridis@aua.gr <ykotseridis@aua.gr>
FAU - Spink, M
AU  - Spink M
FAU - Brindle, I D
AU  - Brindle ID
FAU - Blake, A J
AU  - Blake AJ
FAU - Sears, M
AU  - Sears M
FAU - Chen, X
AU  - Chen X
FAU - Soleas, G
AU  - Soleas G
FAU - Inglis, D
AU  - Inglis D
FAU - Pickering, G J
AU  - Pickering GJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080302
PL  - Netherlands
TA  - J Chromatogr A
JT  - Journal of chromatography. A
JID - 9318488
RN  - 0 (Isotopes)
RN  - 0 (Pyrazines)
SB  - IM
MH  - Beverages/*analysis
MH  - Calibration
MH  - Isotopes
MH  - Magnetic Resonance Spectroscopy
MH  - Pyrazines/*analysis
MH  - Reference Standards
MH  - Reproducibility of Results
MH  - Sensitivity and Specificity
MH  - Wine/*analysis
EDAT- 2008/04/02 09:00
MHDA- 2008/08/14 09:00
CRDT- 2008/04/02 09:00
PHST- 2007/12/28 00:00 [received]
PHST- 2008/02/20 00:00 [revised]
PHST- 2008/02/25 00:00 [accepted]
PHST- 2008/04/02 09:00 [pubmed]
PHST- 2008/08/14 09:00 [medline]
PHST- 2008/04/02 09:00 [entrez]
AID - S0021-9673(08)00396-8 [pii]
AID - 10.1016/j.chroma.2008.02.088 [doi]
PST - ppublish
SO  - J Chromatogr A. 2008 May 9;1190(1-2):294-301. doi: 10.1016/j.chroma.2008.02.088. 
      Epub 2008 Mar 2.