[RADIOCARBON, VOL. 34, No. 3, 1992, P.

768-7711"C IN AUSTRIAN WINE AND VINEGARFRANZ SCHONHOFER

Federal Institute for Food Control and Research,

Kinderspitalgasse 15, A-1090 Wien, Austria

scintillation
Vienna for "C and 3H, using an ultra-low-level liquid
ABSTRACT. I analyzed wine from the vicinity ofcurve, which was applied
calibration
aestablish
tousedwas1987
tocounter. A series of certified samples from 1955
vinegar, which I
simple extraction method to isolate acetic acid fromsuccessfully to a sample of apricot brandy. I used acontained tooowine
fromcocktail. A sample labeled as manufactured
measured directly after mixture with a scintillation
acetic acid also showed
technical-gradeandAnalyticaladulterated.
high a concentration of "C, and thus may have beenthat they are produced from organic material.
different concentrations of "C, although it is unlikely

INTRODUCTION
14C and 3H were released during atmospheric nuclear tests in the 1950s andLarge amounts ofradionuclides have declined characteristi1960s. Since the test moratorium, concentrations of bothmaterial. Fermentation of carbohydrates incally. Both radionuclides are assimilated into plant
14C
and 3H in alcohol reflects the concentration
grapes yields alcohol; thus, the concentration ofprovide information about the natural origin of
in the atmosph ere.14C and 3H determinations canwhich can be used to determine the age ofmany substances including alcohol and vinegar,
this study was to establish reliable calibration
alcoholic beverages of a certain vintage. The aim of
14C in acetic acidpossibility of measuring
curves for alcoholic beverages and to investigate theisolated from vinegar.

METHODOLOGYQuantulus counters. Superior counting
For this study, I used two ultra-low-level liquid scintillationand heavy passive shielding result
performance can be achieved with these instruments, as active
for a very low detection limit and shorterin very low background. The counting system allows
measurement times to enhance sample throughput.
and the optimization of counting
Schonhofer (1989) described the sample preparation procedure
14C determinations, ethanol
14C
and 3H from alcoholic beverages. For
conditions for analysis of
to about 90% (volume). I mixed 10from wine is concentrated in a two-step distillation procedure
in a PET- or PTFE-lined polyethylene
ml of this ethanol with 10 ml of cocktail (Quickszint 400)of the same concentration. I determinedvial. Background is determined using 14C-free ethanolof n-hexadecane in absolute ethanol.
counting efficiency for all samples using an internal standardof the ethanol distillation, and 3H
For 3H measurements, pure water is distilled from the residue
12 ml of Quickszint 400 in a PTFE-lined
is determined by mixing 8 ml of this water with
polyethylene vial.
by continuous extraction withFor 14C measurements in vinegar, acetic acid was isolated1977). Concentrated acetic
Kenndler&Fogy(Schmid,
di -isopropY1 ether and subsequent distillation
efficiency andmiscibility,
foroptimized
wereacid was used as such. Measurement conditions
Quickszint 400 in a PTFE-lined
background,' 4 ml of the sample were mixed with 6 ml
standard of n-hexadecane.
polyethylene vial. Efficiency was determined by adding an internal
was 47%, and the figure of merit
Background was 0.65 cpm in the optimized window, efficiency<1%.
was 3405. For 1000-min measuring time, the 3 v error wasRESULTS FOR "C AND 3H IN WINESchonhofer (1989) already discussed some factors influencing768

the concentration of14C and 3H in

"C in Austrian Wine and Vinegar

769

wine. For this study, I obtained wine samples from HBLVA Klosterneuburg, a school for viniculture near Vienna; the samples were cultivated in the same small area and were guaranteed tobe from a single harvest year, over the range 1955-1987.
Figure 1 shows 14C results for these samples; Figure 2 shows 3H results. All values represent atleast triplicate analyses; in all cases, measurement time was 500 min. 3 a error bars are presented.
Bq/g carbon(pCi/g C)

0,50 1----

13,50,45
didi0,40

10,8Ii

1i0,351i

di0,30di di8,1dfi

di dirhd,

di0,25d,0,20 IIIIIIIIIIItIIl111911itI1111111L1W11k1If1111111If1111L LI II1llilll111l111111W1111iIIIllil
55

60

65

7075

5,485

80

Fig. 1.14C in wine. HBLVA Klosterneuburg

Year of harvestoc

Bq/litrer---(nCi/1)
1,62501,35401,08300,8120
di0,54i0,2710d1

didio1th55

Iih111ll

60

IIf 11111!1111111ll Ill

6570di1l1111111111111fLI1.

75

Year of harvest

80

0,0085

Fig. 2.3H in wine. HBLVA Klosterneuburg

770Franz Schonhofer

These data sets show a much smoother trend than previous data (Schonhofer 1989). One reason
might be that initial measurements were made on commercial samples; another might be that ourcurrent use of an internal standard allowed for a more precise efficiency determination than parallel
standards run with approximately equal ethanol concentrations.
14Cand 3H differences between wines produced from different grape
varieties of the same year, nor between red and white wines.
I observed no significant

The calibration curve was successfully tested on a sample of apricot brandy. The year of distillation
was unknown to the analyst, but was known to have been produced from a single harvest year. Inprinciple, the possibility of different 14C concentrations in the brandy might be explained bydifferent assimilation of apricots. Thus, based on measured 14C and 3H concentration, I cautiouslyassigned a range of 1962-1965; the brandy sample was actually distilled in 1963. Figures 1 and2 show that relatively precise age determinations can be made over the range 1955-1975; after1975, smaller annual 14C and 3H differences preclude age determination more precise than 5-7 yr.
RESULTS FOR 14C IN VINEGAR

For 14C determination in acetic acid, a background sample containing 14C-free acetic acid wasrequired. Several samples of analytical- and technical-grade acetic acid were tested for use asbackground, because it was likely that they were produced from petroleum hydrocarbons. At first,14C,perhaps because 14C-labeled acetic acid had been added. Finally,
I found no sample free of"Riedel-deHaen" acetic acid proved to be 14C-free, and was used for background determination.

Figure 3 summarizes the 14C concentrations in different acetic acid samples. L1, L2 and D wereisolated from vinegars labeled as produced by fermentation from wine; "Merck" was analyticalgrade acetic acid; "Neuber" and "Techn" were technical-grade acetic acid; "Lenzing" was produced
from wood. "Old" acetic acid was produced long before atmospheric nuclear testing (it was foundin a chemical institute; label and bottle shape indicated production long before World War II). Allsamples were measured in triplicate; error bars represent 3 a.
The "Old" sample reflects the natural concentration of 14C before nuclear weapons testing. L1 andL2 results correspond to the 14C concentration in wine of recent years. Thus, I concluded that these0,30

Bq C-14/g C}

0,260,240,220,20Fig. 3.14C in acetic acidOldL1L2DMerck+ 3 sigma error

Techn Lenzing Neuber

14C

in Austrian Wine and Vinegar

771

vinegars probably originated from wine, although other fruit sources cannot
be excluded. "Neuber"and "Techn" technical-grade acetic acids have a 14C concentration similar
to that of "Lenzin g "wood-derived acetic acid, approximately 0.27 B
Csuggestingthat the two technical-gradeq gacetic acids may have derived from wood. This activity corresponds to the1980 level (Fig. 1),
indicating that 10- y r old trees may have been used to manufacture thesetechnical-grade
aceticacids. On the other hand, 14C concentration of ethanol produced from woodin 1988 was 0.30 B q
C, suggesting the use of 15-20- r-old wood in its manufacture.
YThis is difficult to verify, as
the factory closed recently. Artificial labeling also cannot be excluded.
The "Merck" sample shows an even higher concentration of 14C, although it seems
unlikely thatanalytical-grade acetic acid is produced from wood.

The D sample, labeled as originating from wine, has a 14C concentration higher
than in samples
L1, L2 and contemporary wine, indicating that it was not produced fromwine. Its activity corresponds to 1980 wine. Normally, wine would not be kept for 10 years toproduce vinegar, norwould vinegar be kept for 10 years until sold. Both possibilities would have resulted
a high price- but this D-sample vinegar had a suspiciously low price. Acetic acid derived frominrelatively
oldwood may have been used to produce the D sample; a more likely possibility
is dilution ofanalytical-grade acetic acid, labeled artificially with 14C. Earlier comparative studies 14Cofand 3H
concentrations and 13C/12C ratios showed that 14C concentration in a sample of analytical-grade
acetic acid corresponded to the biogenic concentration; 3H concentration did not.
The 13C/12C ratio
indicated a non-biogenic origin for this analytical-grade acetic acid (Schmid1977, 1978a,b .
CONCLUSIONS

Ethanol and acetic acid can be measured directly and precisely in an ultra-low-levelliquidscintillation counter, thus avoiding expensive, time-consuming chemical preparations
such asbenzene synthesis.

Measurements of 14C and 3H concentration allow age determination of wine and otheralcoholic
beverages from approximately the last 35 years. False labeling may also be detected
fromtheseanalyses. 14C analysis of vinegar may verify its origin and may uncover adulterations.
ACKNOWLEDGMENTS
I thank many individuals and institutions for their kind cooperation;

J. Gyimothy, Director, Federal
Institute for Food Control and Research, for providing the test sample of apricot brandy;
S. Weiss,Director, HBLVA Klosterneuburg, and W. Meier for providing the precious wine samples
anddiscussions about the art of wine making; E. Schmid, Analytical Institute, Universityof Vienna,for providing samples of vinegar; E. Findeis, Federal Institute for Food Control andResearch, andJeffrey A. Brown, Arizona State University, for distilling samples and evaluating data.
REFERENCES
Schmid, E. R., Fogy, I. and Kenndler, E. 1977 Beitragzur Unterscheidung von Garungsessig und synthetischem Saureessig lurch die Bestimmung der spezifischen 14C-Radioaktivitat. Zeitschrift ft r LebensmittelUntersuchung und -Forschung 163: 121-122.
-_-_j978a Beitrag zur Unterscheidung von Garungsessig und synthetischem Saureessig lurch diemassenspektrometrische Bestimmung des 13C/12C-Isotopenverhltnisses. Zeitschrift fur Lebensmittel-Untersuchung und -Forschung 166: 89-92.

Schmid, E. R., Fogy, I. and Kenndler, E. 1978b Beitragzur Unterscheidung von Garungsessig und synthetischem Essig lurch die Bestimmung der spezifischen
3H-Radioaktivitat. Zeitschrift fur Lebensmittel-Untersuchung und -Forschung 166: 221-224.
Schonhofer, F. 1989 Determination of 14C in alcoholic
beverages. In Long, A. and Kra, R. S., eds., Proceedings of the 13th International 14C Conference. Radiocarbon 31(3): 777-784.