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Investigation into the benzene and toluene content of soft drinks
Food Control 12 (2001) 505±509
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Investigation into the benzene and toluene content of soft drinks F. Fabietti *, M. Delise, A. Piccioli Bocca Food Department, Istituto Superiore di Sanit a,Viale Regina Elena 299, 00161 Rome, Italy Received 1 May 2000; received in revised form 2 April 2001; accepted 27 April 2001
Abstract Sixty samples of dierent types of soft drinks with an aqueous base were analysed (Cola, Cola light, orange, carbonated) for the purpose of evaluating the presence and content of the principal aromatic hydrocarbons responsible for environmental pollution. The analyses were done using the purge and trap technique and gas chromatography combined with mass spectrometry. The deuterated isotopes of the same hydrocarbons were used for quantitative determination by the internal standard technique. Although an examination of the data found does not show values in excess of the limits recommended by the WHO for benzene in drinking water, nevertheless a constant presence of benzene and toluene was found in all the beverages analysed which gives food for thought about a possible cumulative eect, taking the intake of other contaminated foods and environmental pollution into account. Ó 2001 Elsevier Science Ltd. All rights reserved. Keywords: Benzene; Toluene; Soft drinks
1. Introduction The presence of aromatic hydrocarbons, including benzene, in foods arises from various causes, such as transfer from packaging materials, preservation environments, degradation of preservatives, heat, cooking processes and irradiation techniques used for sterilisation. In water, however, the main source is environmental pollution (Gist & Burg, 1997; MAFF Food Safety Directorate, 1995). While the genotoxicity of benzene has been con®rmed by various studies, there are still few toxicological data available for toluene, ethyl benzene and xylene (Gist & Burg, 1997). As already shown in earlier work (Fabietti, Delise, & Piccioli Bocca, 2000), foods with high lipid contents are more at risk from contamination during both the manufacturing process and the packaging phase because the aromatic hydrocarbons are, because of their chemical structure, highly lipophilic. It was thought advisable, however, to extend the investigation to foods not containing lipid materials and, in this study, we turned our attention to soft drinks because of their high consumption, especially by children and teenagers.
There are no legal limits for the contaminants under examination, except for benzene, and that only relates to drinking water for which the WHO has laid down guidelines that provide for a maximum content of this hydrocarbon up to 10 lg kg 1 (Science Communication On Food, 1999). There is little data in the literature relating to the presence of aromatic hydrocarbons in aqueous-based soft drinks and they are only part of general investigations carried out on all foods (Entz, Thomas, & Diachenko, 1982; McNeal, Holli®eld, & Diachenko, 1995; Page & Lacroix, 1993). The purpose of this study for the abovementioned hydrocarbons was to evaluate quantitatively their possible presence in beverages which are widely consumed especially by teenagers. The TDI ®xed by the WHO for each of the aromatic hydrocarbons considered is: 223 lg kg 1 of body weight for toluene, 179 lg kg 1 of body weight for xylene and 97:1 lg kg 1 of body weight for ethyl benzene (Science Communication On Food, 1999). No limits have been ®xed for benzene because it has been con®rmed to be carcinogenic.
2. Materials and methods *
Corresponding author. Tel.: +39-06-49902046; fax: +39-0649902377. E-mail address: [email protected] (F. Fabietti).
Sixty samples were analysed, divided into groups according to type:
0956-7135/01/$ - see front matter Ó 2001 Elsevier Science Ltd. All rights reserved. PII: S 0 9 5 6 - 7 1 3 5 ( 0 1 ) 0 0 0 4 1 - X
506
F. Fabietti et al. / Food Control 12 (2001) 505±509
· 20 beverages made from Cola, · 10 ``light'' beverages made from Cola, · 15 beverages made from orange juice, · 15 carbonated beverages. Fifteen of the 20 Cola-based samples were in cans and ®ve in glass bottles; the other samples were in cans. All the samples came from warehouses or retailers in various Italian cities and were produced by the same ®rm in dierent factories. The aromatic hydrocarbons were analysed by gas chromatography combined with mass spectrometry, using the purge and trap technique. The aromatic hydrocarbons in a deuterated form were used as the internal standards for quantitative analysis. This avoids the need to use correction factors for the dierent response that the instrument may give to the various hydrocarbons if only one standard was used. Also, compared to calibration by external standards, there are fewer repeatability problems and the method is more rapid, since there is no need to repeat the calibration lines periodically to check on the sensitivity of the instrument and retention times. The samples were kept in a refrigerator until the moment of the analysis, to prevent any accumulation of vapours in the head space, and the test sample, for adding the internal standards, was taken immediately after opening, to prevent loss of volatile components through the immediate emission of carbon dioxide that occurs when the can is opened. To verify the retention times of the hydrocarbon peaks and proceed with their identi®cation, standard solutions of each hydrocarbon were prepared in methanol. Such solutions have been diluted until a concentration was obtained, that would give such a concentration of about 10 mg kg 1 for each
hydrocarbon, if such solutions were added to a quantity of each totally outgassed beverages. These solutions were analysed using the complete scanning method (SCAN MODE) and comparing the spectra obtained with those present in the instrument's library (NBS 75 K) (Fig. 1). For quantitative analysis, deuterated hydrocarbon standards each at a concentration of 10 lg kg 1 were added to the samples and the single ions monitored (SIM MODE). The retention times of deuterated hydrocarbon internal standards are almost the same as for normal hydrocarbons, therefore the ``extract ion'' technique was used, which makes it possible to evaluate the areas of the most abundant ions related to the fragmentation of the single compounds. The following ions were taken into consideration: 77± 78±84±91±92±98±100±105±106±116 m z 1 . The limit of detection was 0:05 lg kg 1 (obtained considering ®ve times the background noise) for each of the hydrocarbons being analysed. Each sample was analysed in triplicate. An aliquot of 5 ml of sample, taken from the solutions described above, was put into the U glass vessel without a ®lter bae and this was connected to the Hewlett±Packard 7695 purge and trap apparatus. The operating conditions before putting into the column were as follows: · purge with a helium ¯ow at ambient temperature (22± 25°C) for 11 min (6); · adsorption on a speci®c BTEX-Hewlett±Packard trap; · desorption at 180°C for 8 min; · cryofocussing at the head of the column by cooling with liquid nitrogen at )150°C.
Fig. 1. Hydrocarbons standards: (1) benzene; (2) toluene; (3) ethylbenzene; (4) (m,p)-xylene; (5) o-xylene.
n1 n2 n3 n4 n5 n6 n7 n8 n9 n10 n11 n12 n13 n14 n15 n16
Toluene
Mean (n) S.D.
n1 n2 n3 n4 n5 n6 n7 n8 n9 n10 n11 n12 n13 n14 n15 n16 n17 n18 n19 n20
Samples
Benzene
Table 1
1.96 2.33 2.48 3.00 2.52 2.44 3.08 4.15 1.97 3.00 3.90 3.28 2.60 2.90 2.95 2.73
1.81 2.36 2.58 2.74 2.70 2.38 3.19 4.22 2.20 3.27 4.20 3.40 2.73 2.85 3.01 2.60
1.93 2.39 2.71 2.68 2.62 2.67 3.03 4.08 2.13 3.33 4.18 3.52 2.75 2.92 3.04 2.74
1.80 1.27 1.72 1.50 2.40 2.50 1.16 1.72 1.54 1.24 1.56 2.62 1.38 1.25 1.76 1.50 1.91 1.71 2.20 1.49
1.9 2.4 2.6 2.8 2.6 2.5 3.1 4.2 2.1 3.2 4.1 3.4 2.7 2.9 3.0 2.7
1.7 0.4
1.7 1.2 1.6 1.5 2.1 2.5 1.1 1.6 1.6 1.3 1.6 2.6 1.5 1.3 1.8 1.5 2.0 1.7 2.2 1.5
0.1 0.0 0.1 0.2 0.1 0.2 0.1 0.1 0.1 0.2 0.2 0.1 0.1 0.04 0.0 0.1
0.1 0.1 0.2 0.1 0.3 0.1 0.1 0.2 0.1 0.1 0.2 0.1 0.2 0.05 0.1 0.1 0.2 0.05 0.1 0.03
3.16 2.88 2.67 2.60 3.80 2.31 2.24 2.75 2.84 2.53
2.55 2.40 2.18 1.95 2.15 2.22 2.16 2.50 2.27 2.50
1.67 1.10 1.42 1.42 2.00 2.40 1.14 1.52 1.62 1.36 1.48 2.55 1.52 1.35 1.84 1.55 1.93 1.65 2.30 1.53
1.63 1.17 1.56 1.48 1.90 2.60 1.00 1.55 1.64 1.22 1.72 2.63 1.52 1.30 1.80 1.45 2.16 1.74 2.10 1.48
3.31 3.00 2.70 2.50 4.21 2.34 2.30 2.58 2.91 2.41
2.71 2.48 2.33 2.00 2.34 2.40 2.00 2.40 2.42 2.57
3.13 3.12 3.03 2.70 3.99 2.25 2.36 2.77 2.95 2.56
2.84 2.32 2.09 2.05 2.41 1.98 2.14 2.60 2.21 2.73
3.2 3.0 2.8 2.6 4.0 2.3 2.3 2.7 2.9 2.5
2.3 0.2
2.7 2.4 2.2 2.0 2.3 2.2 2.1 2.5 2.3 2.6
2nd test 3rd test Mean
1st test
2nd test 3rd test Mean
1st test
S.D.
Light Cola
Cola-based
0.1 0.2 0.2 0.10 0.2 0.0 0.1 0.1 0.1 0.1
0.1 0.1 0.1 0.05 0.1 0.2 0.1 0.1 0.1 0.1
S.D.
2.86 3.10 3.41 2.38 3.15 4.15 3.75 4.38 2.60 4.05 3.92 2.94 2.64 3.10 2.54
2.52 2.55 2.84 2.96 2.98 3.56 2.26 2.90 2.35 3.29 3.15 2.50 2.65 2.85 2.94
1st test
2.91 2.98 3.50 2.25 3.30 4.20 3.82 4.42 2.72 3.93 3.70 2.90 2.72 2.90 2.62
2.44 2.71 2.93 2.85 3.25 3.62 2.41 2.75 2.42 3.16 3.22 2.56 2.69 2.90 2.91
2.89 3.22 3.30 1.96 3.16 3.85 3.83 4.40 2.78 4.02 4.05 2.86 2.70 3.00 2.70
2.54 2.84 2.89 2.87 3.37 3.60 2.23 2.74 2.44 3.45 3.23 2.74 3.06 2.95 2.93
2.9 3.1 3.4 2.2 3.2 4.1 3.8 4.4 2.7 4.0 3.9 2.9 2.7 3.0 2.6
2.9 0.4
2.5 2.7 2.9 2.9 3.2 3.6 2.3 2.8 2.4 3.3 3.2 2.6 2.8 2.9 2.9
2nd test 3rd test Mean
Orange juice
0.0 0.1 0.10 0.2 0.1 0.19 0.0 0.1 0.09 0.1 0.18 0.0 0.0 0.1 0.1
0.1 0.1 0.05 0.1 0.2 0.03 0.1 0.1 0.05 0.1 0.04 0.1 0.2 0.1 0.1
S.D.
5.10 4.90 5.26 5.35 5.27 6.50 6.07 3.35 4.76 5.94 5.60 5.08 6.10 4.53 5.22
2.85 2.90 1.94 3.21 2.50 3.67 1.74 1.61 1.45 1.85 1.66 2.00 1.92 2.00 2.45
1st test
4.87 5.25 5.17 5.42 5.50 6.80 6.20 3.50 4.88 6.11 5.58 5.15 5.85 4.66 5.17
3.40 3.10 1.80 2.97 2.20 3.50 1.85 1.53 1.40 1.91 1.72 1.87 2.18 2.43 2.34
4.73 5.24 5.47 5.43 5.42 6.75 6.03 3.42 5.06 5.95 5.62 5.07 5.75 4.61 5.21
3.35 3.00 1.66 2.82 2.23 3.93 1.81 1.28 1.35 2.10 1.84 1.83 1.88 1.96 2.40
4.9 5.1 5.3 5.4 5.4 6.7 6.1 3.4 4.9 6.0 5.6 5.1 5.9 4.6 5.2
2.3 0.7
3.2 3.0 1.8 3.0 2.3 3.7 1.8 1.5 1.4 2.0 1.7 1.9 2.0 2.1 2.4
2nd test 3rd test Mean
Carbonated type
0.2 0.2 0.2 0.0 0.1 0.2 0.1 0.1 0.2 0.1 0.0 0.0 0.2 0.1 0.0
0.3 0.1 0.1 0.2 0.2 0.2 0.1 0.2 0.1 0.1 0.1 0.1 0.2 0.3 0.1
S.D.
F. Fabietti et al. / Food Control 12 (2001) 505±509 507
5.3 0.8
2nd test 3rd test Mean 1st test 1st test
3.3 0.6 2.8 0.5 Mean (n) S.D.
n17 n18 n19 n20
3.93 2.88 2.66 2.69
2.9 0.6
0.0 0.04 0.1 0.09 3.87 2.87 2.82 2.52 3.90 2.95 2.92 2.60
3.9 2.9 2.8 2.6
2nd test 3rd test Mean 1st test
S.D.
2nd test 3rd test Mean
S.D. 1st test
2nd test 3rd test Mean
S.D.
Carbonated type Orange juice Light Cola Cola-based Samples
Toluene
Table 1 (Continued)
Mean average content of aromatic hydrocarbon for each sample listed in lg kg 1 ; mean (n) average content of aromatic hydrocarbon for each group of beverages listed in lg k 1 ; S.D. standard deviation.
F. Fabietti et al. / Food Control 12 (2001) 505±509 S.D.
508
The injector was brought to 150°C for 1 min, before putting the sample in the column. Injection took place automatically by connection with a Hewlett±Packard 6890 gas chromatograph. The column used was a Supelco SPB-5, length 60 m, 0.20 mm i.d., ®lm thickness 0:20 lm. Gas-chromatographic analysis was performed under the following conditions: Initial temperature Final temperature Temperature increase
40° for 1 min 200° for 5 min 15° min 1
The mass spectrometer had a temperature of 280° at source. Parameters for data acquisiton were: Group Benzene Toluene Ethylbenzene Xylenes
Time interval of sampling (min) 4.50±7.00 7.00±8.00 8.00±10.00 8.00±10.00
Scan rate for sampling (cycles s 1 ) 1.16 1.16 1.16 1.16
Once the holdup times of the various hydrocarbons had been found (SCAN MODE), the samples with the deuterated standards added at the known concentration (10 lg kg 1 ) were analysed, monitoring the single ions (SIM MODE). Using the ``extract ion'' technique it was possible to analyse the most abundant fragments of the deuterated hydrocarbon internal standards and of the contaminant analytes (normal hydrocarbons). From the confrontation between deuterated hydrocarbon areas with known concentration and those of the contaminant hydrocarbons, a concentration of the latter was tracked down.
3. Results and discussion Table 1 shows the values related to the average concentration (three determinations for each sample, expressed in lg kg 1 ) of the single hydrocarbons found in the soft drinks tested and their standard deviation; it shows the values of the average of the averages and their standard deviation too. The values for the concentration of ethyl benzene and xylenes do not appear because these hydrocarbons were not detected. It was not possible to make a comparison between the average values found and any legal limits, since none have been de®ned. Therefore, it was decided to compare them with the value of 10 lg kg 1 , the limit for benzene in drinking water recommended by the WHO in its guidelines (Science Communication On Food, 1999) and with the values found in the literature for various foods.
F. Fabietti et al. / Food Control 12 (2001) 505±509
None of the samples analysed exceeded this limit: on the contrary, most of them had a much lower aromatic hydrocarbons content. However, attention is drawn to the fact that in one sample only, marked with an asterisk among the carbonated beverages, did the benzene and toluene, when added together, exceed the above-mentioned value of 10 lg kg 1 . With regard to the benzene content in some of the beverages tested, it should be borne in mind that this could, at least in part, be the result of the interaction between the sodium benzoate and the ascorbic acid, both present among the ingredients in the beverages, the former as a preservative and the second as a natural constituent of citrus juices (McNeal et al., 1995). But concern is expressed because of the fact that in many foods, such hydrocarbons have been spotted, as described in the literature. This entails the necessity of a continuous monitoring on their concentration, so that the daily intake through contaminated foods added to the intake due to inhalation or other factors (smoke, water, etc.) does not represent a potential risk factor for consumers' health.
509
References Entz, R. C., Thomas, K. W., & Diachenko, G. W. (1982). Residues of volatile halocarbons in foods using headspace gas chromatography. Journal of Agricultural Food Chemistry, 30, 846±849. Fabietti, F., Delise, M., & Piccioli Bocca, A. (2000). Aromatic hydrocarbon residues in milk: preliminary investigation. Food Control, 11, 313±317. Gist, G. L., & Burg, J. R. (1997). Benzene. A review of the literature from a health eects perspective. Toxicology and Industrial Health, 13(6), 661±714. MAFF Food Safety Directorate. (1995). Benzene and other aromatic hydrocarbons in food. Average UK dietary intakes. Food Surveillance 58, March. McNeal, T. P., Holli®eld, H. C., & Diachenko, G. W. (1995). Survey of trihalomethanes and other volatile chemical contaminants in processed foods by purge and trap capillary gas chromatography with mass selective detection. Journal of AOAC International, 78(2), 391±397. Page, B. D., & Lacroix, G. (1993). Application of solid phase microextraction to the headspace gas chromatographic analysis of halogenated volatiles in selected foods. Journal of Chromatography, 648, 199±211. Science Communication On Food. (1999). SCF/CS/CNTM/OLIVE/ 9 FINAL January.
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Investigation into the benzene and toluene content of soft drinks F. Fabietti *, M. Delise, A. Piccioli Bocca Food Department, Istituto Superiore di Sanit a,Viale Regina Elena 299, 00161 Rome, Italy Received 1 May 2000; received in revised form 2 April 2001; accepted 27 April 2001
Abstract Sixty samples of dierent types of soft drinks with an aqueous base were analysed (Cola, Cola light, orange, carbonated) for the purpose of evaluating the presence and content of the principal aromatic hydrocarbons responsible for environmental pollution. The analyses were done using the purge and trap technique and gas chromatography combined with mass spectrometry. The deuterated isotopes of the same hydrocarbons were used for quantitative determination by the internal standard technique. Although an examination of the data found does not show values in excess of the limits recommended by the WHO for benzene in drinking water, nevertheless a constant presence of benzene and toluene was found in all the beverages analysed which gives food for thought about a possible cumulative eect, taking the intake of other contaminated foods and environmental pollution into account. Ó 2001 Elsevier Science Ltd. All rights reserved. Keywords: Benzene; Toluene; Soft drinks
1. Introduction The presence of aromatic hydrocarbons, including benzene, in foods arises from various causes, such as transfer from packaging materials, preservation environments, degradation of preservatives, heat, cooking processes and irradiation techniques used for sterilisation. In water, however, the main source is environmental pollution (Gist & Burg, 1997; MAFF Food Safety Directorate, 1995). While the genotoxicity of benzene has been con®rmed by various studies, there are still few toxicological data available for toluene, ethyl benzene and xylene (Gist & Burg, 1997). As already shown in earlier work (Fabietti, Delise, & Piccioli Bocca, 2000), foods with high lipid contents are more at risk from contamination during both the manufacturing process and the packaging phase because the aromatic hydrocarbons are, because of their chemical structure, highly lipophilic. It was thought advisable, however, to extend the investigation to foods not containing lipid materials and, in this study, we turned our attention to soft drinks because of their high consumption, especially by children and teenagers.
There are no legal limits for the contaminants under examination, except for benzene, and that only relates to drinking water for which the WHO has laid down guidelines that provide for a maximum content of this hydrocarbon up to 10 lg kg 1 (Science Communication On Food, 1999). There is little data in the literature relating to the presence of aromatic hydrocarbons in aqueous-based soft drinks and they are only part of general investigations carried out on all foods (Entz, Thomas, & Diachenko, 1982; McNeal, Holli®eld, & Diachenko, 1995; Page & Lacroix, 1993). The purpose of this study for the abovementioned hydrocarbons was to evaluate quantitatively their possible presence in beverages which are widely consumed especially by teenagers. The TDI ®xed by the WHO for each of the aromatic hydrocarbons considered is: 223 lg kg 1 of body weight for toluene, 179 lg kg 1 of body weight for xylene and 97:1 lg kg 1 of body weight for ethyl benzene (Science Communication On Food, 1999). No limits have been ®xed for benzene because it has been con®rmed to be carcinogenic.
2. Materials and methods *
Corresponding author. Tel.: +39-06-49902046; fax: +39-0649902377. E-mail address: [email protected] (F. Fabietti).
Sixty samples were analysed, divided into groups according to type:
0956-7135/01/$ - see front matter Ó 2001 Elsevier Science Ltd. All rights reserved. PII: S 0 9 5 6 - 7 1 3 5 ( 0 1 ) 0 0 0 4 1 - X
506
F. Fabietti et al. / Food Control 12 (2001) 505±509
· 20 beverages made from Cola, · 10 ``light'' beverages made from Cola, · 15 beverages made from orange juice, · 15 carbonated beverages. Fifteen of the 20 Cola-based samples were in cans and ®ve in glass bottles; the other samples were in cans. All the samples came from warehouses or retailers in various Italian cities and were produced by the same ®rm in dierent factories. The aromatic hydrocarbons were analysed by gas chromatography combined with mass spectrometry, using the purge and trap technique. The aromatic hydrocarbons in a deuterated form were used as the internal standards for quantitative analysis. This avoids the need to use correction factors for the dierent response that the instrument may give to the various hydrocarbons if only one standard was used. Also, compared to calibration by external standards, there are fewer repeatability problems and the method is more rapid, since there is no need to repeat the calibration lines periodically to check on the sensitivity of the instrument and retention times. The samples were kept in a refrigerator until the moment of the analysis, to prevent any accumulation of vapours in the head space, and the test sample, for adding the internal standards, was taken immediately after opening, to prevent loss of volatile components through the immediate emission of carbon dioxide that occurs when the can is opened. To verify the retention times of the hydrocarbon peaks and proceed with their identi®cation, standard solutions of each hydrocarbon were prepared in methanol. Such solutions have been diluted until a concentration was obtained, that would give such a concentration of about 10 mg kg 1 for each
hydrocarbon, if such solutions were added to a quantity of each totally outgassed beverages. These solutions were analysed using the complete scanning method (SCAN MODE) and comparing the spectra obtained with those present in the instrument's library (NBS 75 K) (Fig. 1). For quantitative analysis, deuterated hydrocarbon standards each at a concentration of 10 lg kg 1 were added to the samples and the single ions monitored (SIM MODE). The retention times of deuterated hydrocarbon internal standards are almost the same as for normal hydrocarbons, therefore the ``extract ion'' technique was used, which makes it possible to evaluate the areas of the most abundant ions related to the fragmentation of the single compounds. The following ions were taken into consideration: 77± 78±84±91±92±98±100±105±106±116 m z 1 . The limit of detection was 0:05 lg kg 1 (obtained considering ®ve times the background noise) for each of the hydrocarbons being analysed. Each sample was analysed in triplicate. An aliquot of 5 ml of sample, taken from the solutions described above, was put into the U glass vessel without a ®lter bae and this was connected to the Hewlett±Packard 7695 purge and trap apparatus. The operating conditions before putting into the column were as follows: · purge with a helium ¯ow at ambient temperature (22± 25°C) for 11 min (6); · adsorption on a speci®c BTEX-Hewlett±Packard trap; · desorption at 180°C for 8 min; · cryofocussing at the head of the column by cooling with liquid nitrogen at )150°C.
Fig. 1. Hydrocarbons standards: (1) benzene; (2) toluene; (3) ethylbenzene; (4) (m,p)-xylene; (5) o-xylene.
n1 n2 n3 n4 n5 n6 n7 n8 n9 n10 n11 n12 n13 n14 n15 n16
Toluene
Mean (n) S.D.
n1 n2 n3 n4 n5 n6 n7 n8 n9 n10 n11 n12 n13 n14 n15 n16 n17 n18 n19 n20
Samples
Benzene
Table 1
1.96 2.33 2.48 3.00 2.52 2.44 3.08 4.15 1.97 3.00 3.90 3.28 2.60 2.90 2.95 2.73
1.81 2.36 2.58 2.74 2.70 2.38 3.19 4.22 2.20 3.27 4.20 3.40 2.73 2.85 3.01 2.60
1.93 2.39 2.71 2.68 2.62 2.67 3.03 4.08 2.13 3.33 4.18 3.52 2.75 2.92 3.04 2.74
1.80 1.27 1.72 1.50 2.40 2.50 1.16 1.72 1.54 1.24 1.56 2.62 1.38 1.25 1.76 1.50 1.91 1.71 2.20 1.49
1.9 2.4 2.6 2.8 2.6 2.5 3.1 4.2 2.1 3.2 4.1 3.4 2.7 2.9 3.0 2.7
1.7 0.4
1.7 1.2 1.6 1.5 2.1 2.5 1.1 1.6 1.6 1.3 1.6 2.6 1.5 1.3 1.8 1.5 2.0 1.7 2.2 1.5
0.1 0.0 0.1 0.2 0.1 0.2 0.1 0.1 0.1 0.2 0.2 0.1 0.1 0.04 0.0 0.1
0.1 0.1 0.2 0.1 0.3 0.1 0.1 0.2 0.1 0.1 0.2 0.1 0.2 0.05 0.1 0.1 0.2 0.05 0.1 0.03
3.16 2.88 2.67 2.60 3.80 2.31 2.24 2.75 2.84 2.53
2.55 2.40 2.18 1.95 2.15 2.22 2.16 2.50 2.27 2.50
1.67 1.10 1.42 1.42 2.00 2.40 1.14 1.52 1.62 1.36 1.48 2.55 1.52 1.35 1.84 1.55 1.93 1.65 2.30 1.53
1.63 1.17 1.56 1.48 1.90 2.60 1.00 1.55 1.64 1.22 1.72 2.63 1.52 1.30 1.80 1.45 2.16 1.74 2.10 1.48
3.31 3.00 2.70 2.50 4.21 2.34 2.30 2.58 2.91 2.41
2.71 2.48 2.33 2.00 2.34 2.40 2.00 2.40 2.42 2.57
3.13 3.12 3.03 2.70 3.99 2.25 2.36 2.77 2.95 2.56
2.84 2.32 2.09 2.05 2.41 1.98 2.14 2.60 2.21 2.73
3.2 3.0 2.8 2.6 4.0 2.3 2.3 2.7 2.9 2.5
2.3 0.2
2.7 2.4 2.2 2.0 2.3 2.2 2.1 2.5 2.3 2.6
2nd test 3rd test Mean
1st test
2nd test 3rd test Mean
1st test
S.D.
Light Cola
Cola-based
0.1 0.2 0.2 0.10 0.2 0.0 0.1 0.1 0.1 0.1
0.1 0.1 0.1 0.05 0.1 0.2 0.1 0.1 0.1 0.1
S.D.
2.86 3.10 3.41 2.38 3.15 4.15 3.75 4.38 2.60 4.05 3.92 2.94 2.64 3.10 2.54
2.52 2.55 2.84 2.96 2.98 3.56 2.26 2.90 2.35 3.29 3.15 2.50 2.65 2.85 2.94
1st test
2.91 2.98 3.50 2.25 3.30 4.20 3.82 4.42 2.72 3.93 3.70 2.90 2.72 2.90 2.62
2.44 2.71 2.93 2.85 3.25 3.62 2.41 2.75 2.42 3.16 3.22 2.56 2.69 2.90 2.91
2.89 3.22 3.30 1.96 3.16 3.85 3.83 4.40 2.78 4.02 4.05 2.86 2.70 3.00 2.70
2.54 2.84 2.89 2.87 3.37 3.60 2.23 2.74 2.44 3.45 3.23 2.74 3.06 2.95 2.93
2.9 3.1 3.4 2.2 3.2 4.1 3.8 4.4 2.7 4.0 3.9 2.9 2.7 3.0 2.6
2.9 0.4
2.5 2.7 2.9 2.9 3.2 3.6 2.3 2.8 2.4 3.3 3.2 2.6 2.8 2.9 2.9
2nd test 3rd test Mean
Orange juice
0.0 0.1 0.10 0.2 0.1 0.19 0.0 0.1 0.09 0.1 0.18 0.0 0.0 0.1 0.1
0.1 0.1 0.05 0.1 0.2 0.03 0.1 0.1 0.05 0.1 0.04 0.1 0.2 0.1 0.1
S.D.
5.10 4.90 5.26 5.35 5.27 6.50 6.07 3.35 4.76 5.94 5.60 5.08 6.10 4.53 5.22
2.85 2.90 1.94 3.21 2.50 3.67 1.74 1.61 1.45 1.85 1.66 2.00 1.92 2.00 2.45
1st test
4.87 5.25 5.17 5.42 5.50 6.80 6.20 3.50 4.88 6.11 5.58 5.15 5.85 4.66 5.17
3.40 3.10 1.80 2.97 2.20 3.50 1.85 1.53 1.40 1.91 1.72 1.87 2.18 2.43 2.34
4.73 5.24 5.47 5.43 5.42 6.75 6.03 3.42 5.06 5.95 5.62 5.07 5.75 4.61 5.21
3.35 3.00 1.66 2.82 2.23 3.93 1.81 1.28 1.35 2.10 1.84 1.83 1.88 1.96 2.40
4.9 5.1 5.3 5.4 5.4 6.7 6.1 3.4 4.9 6.0 5.6 5.1 5.9 4.6 5.2
2.3 0.7
3.2 3.0 1.8 3.0 2.3 3.7 1.8 1.5 1.4 2.0 1.7 1.9 2.0 2.1 2.4
2nd test 3rd test Mean
Carbonated type
0.2 0.2 0.2 0.0 0.1 0.2 0.1 0.1 0.2 0.1 0.0 0.0 0.2 0.1 0.0
0.3 0.1 0.1 0.2 0.2 0.2 0.1 0.2 0.1 0.1 0.1 0.1 0.2 0.3 0.1
S.D.
F. Fabietti et al. / Food Control 12 (2001) 505±509 507
5.3 0.8
2nd test 3rd test Mean 1st test 1st test
3.3 0.6 2.8 0.5 Mean (n) S.D.
n17 n18 n19 n20
3.93 2.88 2.66 2.69
2.9 0.6
0.0 0.04 0.1 0.09 3.87 2.87 2.82 2.52 3.90 2.95 2.92 2.60
3.9 2.9 2.8 2.6
2nd test 3rd test Mean 1st test
S.D.
2nd test 3rd test Mean
S.D. 1st test
2nd test 3rd test Mean
S.D.
Carbonated type Orange juice Light Cola Cola-based Samples
Toluene
Table 1 (Continued)
Mean average content of aromatic hydrocarbon for each sample listed in lg kg 1 ; mean (n) average content of aromatic hydrocarbon for each group of beverages listed in lg k 1 ; S.D. standard deviation.
F. Fabietti et al. / Food Control 12 (2001) 505±509 S.D.
508
The injector was brought to 150°C for 1 min, before putting the sample in the column. Injection took place automatically by connection with a Hewlett±Packard 6890 gas chromatograph. The column used was a Supelco SPB-5, length 60 m, 0.20 mm i.d., ®lm thickness 0:20 lm. Gas-chromatographic analysis was performed under the following conditions: Initial temperature Final temperature Temperature increase
40° for 1 min 200° for 5 min 15° min 1
The mass spectrometer had a temperature of 280° at source. Parameters for data acquisiton were: Group Benzene Toluene Ethylbenzene Xylenes
Time interval of sampling (min) 4.50±7.00 7.00±8.00 8.00±10.00 8.00±10.00
Scan rate for sampling (cycles s 1 ) 1.16 1.16 1.16 1.16
Once the holdup times of the various hydrocarbons had been found (SCAN MODE), the samples with the deuterated standards added at the known concentration (10 lg kg 1 ) were analysed, monitoring the single ions (SIM MODE). Using the ``extract ion'' technique it was possible to analyse the most abundant fragments of the deuterated hydrocarbon internal standards and of the contaminant analytes (normal hydrocarbons). From the confrontation between deuterated hydrocarbon areas with known concentration and those of the contaminant hydrocarbons, a concentration of the latter was tracked down.
3. Results and discussion Table 1 shows the values related to the average concentration (three determinations for each sample, expressed in lg kg 1 ) of the single hydrocarbons found in the soft drinks tested and their standard deviation; it shows the values of the average of the averages and their standard deviation too. The values for the concentration of ethyl benzene and xylenes do not appear because these hydrocarbons were not detected. It was not possible to make a comparison between the average values found and any legal limits, since none have been de®ned. Therefore, it was decided to compare them with the value of 10 lg kg 1 , the limit for benzene in drinking water recommended by the WHO in its guidelines (Science Communication On Food, 1999) and with the values found in the literature for various foods.
F. Fabietti et al. / Food Control 12 (2001) 505±509
None of the samples analysed exceeded this limit: on the contrary, most of them had a much lower aromatic hydrocarbons content. However, attention is drawn to the fact that in one sample only, marked with an asterisk among the carbonated beverages, did the benzene and toluene, when added together, exceed the above-mentioned value of 10 lg kg 1 . With regard to the benzene content in some of the beverages tested, it should be borne in mind that this could, at least in part, be the result of the interaction between the sodium benzoate and the ascorbic acid, both present among the ingredients in the beverages, the former as a preservative and the second as a natural constituent of citrus juices (McNeal et al., 1995). But concern is expressed because of the fact that in many foods, such hydrocarbons have been spotted, as described in the literature. This entails the necessity of a continuous monitoring on their concentration, so that the daily intake through contaminated foods added to the intake due to inhalation or other factors (smoke, water, etc.) does not represent a potential risk factor for consumers' health.
509
References Entz, R. C., Thomas, K. W., & Diachenko, G. W. (1982). Residues of volatile halocarbons in foods using headspace gas chromatography. Journal of Agricultural Food Chemistry, 30, 846±849. Fabietti, F., Delise, M., & Piccioli Bocca, A. (2000). Aromatic hydrocarbon residues in milk: preliminary investigation. Food Control, 11, 313±317. Gist, G. L., & Burg, J. R. (1997). Benzene. A review of the literature from a health eects perspective. Toxicology and Industrial Health, 13(6), 661±714. MAFF Food Safety Directorate. (1995). Benzene and other aromatic hydrocarbons in food. Average UK dietary intakes. Food Surveillance 58, March. McNeal, T. P., Holli®eld, H. C., & Diachenko, G. W. (1995). Survey of trihalomethanes and other volatile chemical contaminants in processed foods by purge and trap capillary gas chromatography with mass selective detection. Journal of AOAC International, 78(2), 391±397. Page, B. D., & Lacroix, G. (1993). Application of solid phase microextraction to the headspace gas chromatographic analysis of halogenated volatiles in selected foods. Journal of Chromatography, 648, 199±211. Science Communication On Food. (1999). SCF/CS/CNTM/OLIVE/ 9 FINAL January.