3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
P29 MuLTIELEMENTAL PROFILING AS
FINGERPRINT OF wINES by SIZE-
ExCLuSION COuPLED TO uV AND ICP-MS
TAMARA GARCíA-BARRERA and JOSé LUIS GóMEZ-
ARIZA
Departamento de Química y Ciencia de los Materiales,
Facultad de Ciencias Experimentales, Campus de El Carmen,
Avda. de Fuerzas Armadas S/N, 21007-Huelva, Spain,
tamara@dqcm.uhu.es
Introduction
A number of studies describes the levels of metals in wines
1,2 and organic compounds with high complexation capacity
with them like anthocyanins 3 , phenolic compounds 4,5 ,
and so on. Correlation of metals and organic compound has
been pointed out but it can not be probed since the measurements
were performed off-line. Only in the case of Pb, the
size exclusion chromatography coupled to an inductively
coupled plasma mass spectrometry (SEC-ICP-MS) was used
to determine biomolecular complexes 6 . However, the multielemental
profiling of wines by SEC-ICP-MS has not been
performed until now. This approach has been successfully
applied to the fractionation of several elements in nuts 7,8 ,
soybean flour 9 , and organs from Mus musculus 10 . Multielemental
fractionation studies have also been performed by
SEC-ICP-MS in premature human 11,12 and whey milk 13 . The
aim of this work is to determine the metal-binding molecules
profiles in red and white wines from different grape varieties
as a preliminary step to find key compounds that can be
used as fingerprint as well as to know all the metallospecies
present in wines. The analytical methodology to obtain the
distribution patterns of these elements was based on SEC online
coupled to UV and ICP-MS.
Experimental
S a m p l e s
Samples of red and white wines were purchased in a
local supermarket. All the samples were stored al 4 °C until
analysis. Table I shows the list of wines analyzed and the
assigned codes.
P r o c e d u r e s
The SEC was carried out in a 26/70 XK column packed
with Sephadex LH-20 (hydroxypropylated dextran beads
crosslinked to yield a polysaccharide network) all from
Amersham Biosciences (Uppsala, Sweden). An AKTA-Prime
system (pump and UV detector at 254 nm) (Amersham) was
used as the eluent delivery system, equipped with a 200 µl
sample loop. ICP-MS Agilent, Model 7500 ce (Agilent Technologies,
Tokyo, Japan). The instrumental operating conditions
are given in Table II. Samples were two-fold diluted with
mobile phase and 200 µl was injected in the SEC-UV-ICP-
MS system.The mobile phase for SEC was daily prepared
with a pH 4 methanol-buffer (50 : 50, v/v) solution.
s636
Table I
Analysed samples
Sample Origin Grape Variety Comments
1 nAVARRA Tempranillo, Garnacha Red
2 nAVARRA not determined Red
3 JUMILLA Monastrell Red
4 nAVARRA Garnacha Red
5 RIOJA Tempranillo,
Garnacha, Graciano
Red
6 JUMILLA Monastrell, Tempranillo Red
7 PEnEDéS Tempranillo,
Garnacha, Carieña
Red
8 RIOJA Tempranillo, Garnacha Red
9 VALDEPEÑAS Tempranillo Rosé
10 CAMPO DE BORJA
Tempranillo, Garnacha Red
11 PEnEDéS Garnacha, Cariñena Red
12 LA MAnCHA Tempranillo Red
13
RIBERA
DEL DUERO
not determined Red
14 JUMILLA Monastrell Red
15 RIOJA Tempranillo, Garnacha Red
16 CATALUÑA Macabeo White
17
COnDADO
DE HUELVA
Zalema White
18
COnDADO
DE HUELVA
Zalema, Palomino White
19 PEnEDéS Chardonnay, Parellada White
Table II
Instrumental operating conditions for SEC-UV-ICP-MS
SEC-UV
Column Sephadex LH-20
Exclusión limit 5,000 Da
Mobile phase Methanol-water (pH 4.0)
Flow rate 2 ml min –1
Injection volumen 200 µl
UV-visible wavelength 254 nm
ICP-MS
Forward power 1,500 W
Carrier gas flow rate 0.8 dm 3 min –1
Make up gas 0.1 dm 3 min –1
S/C temperature –2 °C
Sampling depth 8 mm
Sampling and skimmer cones Pt
Dwell Time 0.1 s per isotope
55 Mn, 60 ni, 63 Cu,
Isotopes monitored 66 Zn, 75 As, 208 Pb, 53 Cr,
57 Fe, 59 Co, 82 Se, 111 Cd
Results
The fractionation profiles of the elements in wines are
shown in Figs. 1.–4. Only the most interesting profiles are
discussed in this paper.