Food Additives and Contaminants: Part B Vol. 4, No. 1, March 2011, 1–5
VIEW DATASET Ethyl carbamate levels in wine and spirits from markets in Hebei Province, China Y.P. Liua, B. Donga, Z.S. Qina, N.J. Yanga, Y. Lua, L.X. Yanga, F.Q. Changa* and Y.N. Wub a
Institute of Physical and Chemical Inspection, Hebei Center for Disease Control and Prevention, Shijiazhuang, China; bNational Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China (Received 28 September 2010; final version received 22 January 2011) Ethyl carbamate (EC) in wine, grain spirits and wine sauce (145 samples) was analysed using solid-phase extraction and stable isotope dilution GC/MS. Samples were obtained from markets in eight areas (Shijiazhuang, Baoding, Handan, Qinhuangdao, Langfang, Zhangjiakou, Xingtai and Cangzhou) of Hebei Province, China. The method had a limit of detection of 2 mg kg1, with recoveries varying from 95.7 to 102% and RSD ranging 2.3–5.6%. The average concentrations of ethyl carbamate in wines, grain spirits and wine sauce were 14.7 (52.0– 44.5) mg kg1, 33.8 (2.9–129) mg kg1 and 8.7 (52.0–63.3) mg kg1, respectively. The results led to the development of limit standards that can be used to predict the concentration of ethyl carbamate in Chinese fermented wines. Keywords: alcoholic beverages; process contaminants; ethyl carbamate
Introduction Ethyl carbamate (EC) occurs in most fermented beverages at levels ranging from ng l1 to mg l1 (Beland et al. 2005; Park et al. 2009; Weber and Sharypov 2009). In 1985, high levels of ethyl carbamate were detected in alcoholic beverages in Canada. Consequently, maximum allowable limits (MALs) of ethyl carbamate in wines were set at 30 and 150 mg l1 for grain spirits by the Canadian authorities in the same year. In 2007, the International Agency for Research on Cancer (IARC) assessed ethyl carbamate as ‘‘probably carcinogenic to humans’’ and proposed a maximum daily intake of 0.3 mg kg1 bw (body weight). Fortunately, the issue of EC in alcoholic beverages has attracted a great deal of attention in many countries and reliable methods already exist for analysis of EC, such as GC/MS (Lachenmeier et al. 2005; Park et al. 2009) and GC/MS/MS (Lachenmeier et al. 2006). There are also extensive sample preparation steps; for example, liquid–liquid extraction (LLE), solid phase micro-extraction and solid phase extraction (Ma et al. 1995; Lachenmeier et al. 2009; Weber and Sharypov 2009; Perestrelo et al. 2010). To the best of our knowledge, however, very little data is available on the levels of EC in alcoholic beverages in China. Moreover, no guidelines or regulations yet exist relating to ethyl carbamate in China. In the present study, a large number of samples were
*Corresponding author. Email: [email protected] ISSN 1939–3210 print/ISSN 1939–3229 online ß 2011 Taylor & Francis DOI: 10.1080/19393210.2011.557783 http://www.informaworld.com
analyzed for EC using the official method, namely SPE combined with GC/MS (Canas et al. 1994). The focus of the study was to contribute data for the Chinese authorities to enable them to establish maximum limits for ethyl carbamate in China.
Materials and methods Samples A total of 145 samples were obtained from local markets between May and August 2010 in eight areas (Shijiazhuang, Baoding, Handan, Qinhuangdao, Langfang, Zhangjiakou, Xingtai and Cangzhou) of Hebei Province (China); all were domestic alcoholic beverages. The samples include 48 grain spirits, 57 wines and 40 wine sauces.
Chemicals All solvents were HPLC-grade and purchased from JT Baker (Philipsburg, PA, USA). The Celite diatomaceous earth columns (CARB/NH2, 500 mg/500 mg/ 6 ml) were provide by Hangzhou Fuyu Technology Service Company Limited. The EC standard (99%) was from Sigma-Aldrich (Madrid, Spain). The d5-EC standard (99%) was from Cambridge Isotope Laboratory (Andover, MA, USA).
2
Y.P. Liu et al. Table 1. Recoveries and relative standard deviations (RSDs) for EC. Determined times 1 2 3 1 2 3
Spiking level (mg kg1)
Determined result (mg kg1)
Recovery (%)
37.2 37.2 37.2 186 186 186
33.3 36.5 37.0 185.6 189 194
89.5 98.1 99.4 99.7 102 104.3
Sample pretreatment A liquid sample of 2.0 g was homogenised with 100 ml d5-EC solution (1 mg ml1) as internal standard, and then subjected to SPE column. After an equilibration time of 15 min, 5 ml hexane was used to pre-rinse the column. Next, the analytes were extracted using 10 ml ethyl ether. The eluate was concentrated to dryness under nitrogen gas and re-dissolved in 1 ml of methanol before GC/MS analysis.
GC/MS method The GC/MS system used for analysis was a Thermo Trace-GC in combination with an ultra-DSQ mass spectrometer. A HP-INNOWAX capillary column (30 m 0.25 mm0.25 mm film thickness) was used. The primary oven temperature was programmed from 60 C (3 min) to 160 C (2 min) at 8 C min1, with a post-run temperature of 240 C for 5 min. The injection port was 200 C. Helium was used at a constant flow of 1 ml min1. The MS transfer line temperature was 250 C and the MS source temperature was 230 C. The MS was operated in EI mode at 70 eV. Acquisition was performed in selected ion monitoring mode and m/z 44, 62, 64, 76 and 89 were recorded. For quantitative analysis, m/z 64 for ethyl carbamate-d5 and m/z 62 for ethyl carbamate were chosen. Ion ratios for the EC standard were m/z 62 (100%), m/z 44 (97%) and m/z 89 (5%) and, for d5-EC standard, were m/z 64 (100%), m/z 44 (90%), m/z 76 (20%) and m/z 89 (10%). Confirmation criteria for the identification and quantification of EC include the following: (a) retention time for all m/z monitored for a given analyte should maximize simultaneously 0.2 min, with S/N 3 for each; (b) in all m/z monitored, at least of two ions, the ratio between the two monitored ions should be within 20% of the standard.
Average recovery (%)
RSDs (%)
95.7
5.6
102
2.3
Quality control A five-point calibration curve of EC was created for quantification concentrations: 8.55, 17.1, 51.3, 102.6 and 205.2 mg l1. A high correlation coefficient (r2 ¼ 0.9999) was obtained for the tested interval. Method reproducibility studies were investigated by injecting three replicates of the same standard solution on three different days and on the same day. Both the intra- and inter-day precision showed relative standard deviations (RSDs) below 15%. The recoveries of ethyl carbamate were obtained by analysis of 2.0 g spiked and non-spiked cooking wine, with two spiking levels of 37.2 and 186 mg l1. As shown in Table 1, average recoveries of EC were 95.7 and 102% at the two levels, respectively. The RSD (n ¼ 3) ranged from 5.6 to 2.3%. The limit of detection (LOD) was obtained using standards containing the compounds of interest at low concentration levels at a signal-to-noise ratio of 3. The LOD and LOQ (normally based on S/N ¼ 10) of the present method were 2 and 8 mg kg1, respectively.
Results and discussion As listed in Tables 2–4, the average level of EC in grain spirits was 33.8 mg kg1 (2.9–129 mg kg1), and 14.7 mg kg1 (52.0–44.5 mg kg1) and 8.3 mg kg1 (52.0–63.3 mg kg1), in wines and wine sauce, respectively. The concentrations of EC in grain spirits were clearly higher than in either wines or wine sauce (Figure 1). EC was detected in all grain spirits and wines, but the content in grain spirits were below international guideline levels (150 mg l1). However, higher levels of EC were detected in a minority of grain spirits (90– 129 mg kg1). In the case of wines, about 15% of the alcoholic beverages exceeded the international limit (30 mg l1). In addition, about 88% of wine sauces were below 10 mg kg1, and EC was not detected in many of them. Although EC levels in grain spirits were not particularly high, this may be an important source of EC due to its high consumption.
Food Additives and Contaminants: Part B
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Table 2. EC levels in grain spirits from eight areas of Hebei Province, China (mg kg1). Samples 1 2 3 4 5 6 7 8 9 Average contents
S
Q
B
H
L
Z
X
C
Total average contents
19.5 4.7 2.9 5.8 21.2 16.8 31.1 10.4 19.9 14.7
24.9 36.1 24.9 49.2 92.7 – – – – 45.6
16.3 7.4 16.7 16.4 7.5 – – – – 12.9
34.1 10.6 91.7 22.1 40.9 – – – – 39.9
42.5 18.7 16.1 14.5 8.6 – – – – 20.1
56.8 43.5 30.2 20.1 22.9 – – – – 34.7
55.1 8.56 27.5 30 117.2 23.6 28.6 41.4 15.1 38.6
72.3 34.6 30.7 51.9 129 – – – – 63.7
33.8
Note: –, no samples; S, Shijiazhuang; Q, Qinhuangdao; B, Baoding; H, Handan; L, Langfang; Z, Zhangjiakou; X, Xingtai; C, Cangzhou.
Table 3. EC levels in wines from eight areas of Hebei Province, China (mg kg1). Samples 10 11 12 13 14 15 16 17 18 19 Average contents
S
Q
B
H
L
Z
X
C
Total average contents
9.3 9.2 6.9 26.7 31.8 9.4 8.3 20.1 18.9 14.4 15.5
10.2 10.5 12.4 15.2 4.5 52.0 4.3 6.3 7.1 9.2 8.2
22.1 6.9 12.8 10.7 28.4 6.1 8.0 – – – 13.6
12.4 5.1 14.7 6.1 10.3 – – – – – 9.7
16.8 52.0 2.5 3.3 10.2 – – – – – 7.0
7.3 9.2 15.6 5.5 5.4 – – – – – 8.6
7.7 32.1 32.9 44.5 32.0 17.5 18.3 16.6 16.3 13.8 23.2
31.7 33.8 36.5 25.5 31.8 – – – – – 31.9
14.7
Note: –, no samples; S, Shijiazhuang; Q, Qinhuangdao; B, Baoding; H, Handan; L, Langfang; Z, Zhangjiakou; X, Xingtai; C, Cangzhou.
Table 4. EC levels in wine sauce from eight areas of Hebei Province, China (mg kg1). Samples 20 21 22 23 24 Average contents
S
Q
B
H
L
Z
X
C
Total average contents
21.2 8.3 11.1 9.9 5.6 11.2
5.4 3.4 4.5 3.7 3.6 4.2
52.0 2.9 52.0 4.0 3.3 2.2
4.7 2.8 2.7 4.3 63.3 15.6
52.0 52.0 52.0 2.7 3.4 1.4
6.5 52.0 52.0 52.0 52.0 1.6
3.2 3.7 42.1 46.1 29.5 24.9
4.8 4.7 5.0 4.3 7.5 5.3
8.3
Note: S, Shijiazhuang; Q, Qinhuangdao; B, Baoding; H, Handan; L, Langfang; Z, Zhangjiakou; X, Xingtai; C, Cangzhou.
Comparing the areas sampled, high EC levels (490 mg kg1) were detected in some grain spirits from Qinhuangdao, Handan, Xingtai and Cangzhou. In several wines from Shijiazhuang, Baoding, Xingtai and Cangzhou, EC levels ranged 30–45 mg kg1. Thus, both grain spirits and wines from Cangzhou showed the highest mean levels. It should also be pointed out that the mean level in wines from Cangzhou was a little
higher than the international limit (30 mg l1), with a mean value of 31.9 mg kg1. Additionally, relatively higher concentrations in wine sauce were found in most Xingtai samples, with a level of 25 mg kg1 on average; however, the highest level in wine sauce was obtained in the Handan samples (63.3 mg kg1). The incidence of ethyl carbamate in wines (52.0–44.5 mg kg1) are in close agreement with
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Y.P. Liu et al.
Average content (mg kg–1)
70 60 50 Grain spirits
40
Wines 30
Wine sauce
20 10 0 S
Q
B
H
L
Z
X
C
S–Shijiazhuang, Q–Qinhuangdao, B–Baoding, H–Handan, L–Langfang, Z–Zhangjiakou, X–Xingtai, C–Cangzhou. Figure 1. Average contents of ethyl carbamate in fermented wines from eight areas of Hebei Province, China (mg kg1).
levels in 56 wines (6.0–55.4 mg kg1) reported by Zhou et al. (2007). However, the results are higher than those published elsewhere (Uthurry et al. 2004; Hasnip et al. 2007; Hong et al. 2007). In the UK in 2004. Hasnip et al. (2007) showed that seven European wines contained EC at levels between 11 and 24 mg kg1. A survey in Korea (Hong et al. 2007) showed that EC in wines was 1.7–11.7 mg kg1. Uthurry et al. (2004) analyzed EC in typical Spanish red wines, with results below 25 mg kg1 or at undetected level. Contamination of grain spirits by EC (2.9– 129 mg kg1) in this study was much higher than two similar surveys in Korea (Ha et al. 2006; Hong et al. 2007), with levels of 7–9.5 and 0.8–10.1 mg l1, respectively Our results of EC in wine sauce (52.0– 63.3 mg kg1) were also higher than those reported by Ha et al. (2006) (0.4–0.9 mg l1). However, levels considerably above this, up to 242 mg kg1, have been reported by Fu et al. (2010) in Chinese yellow rice wines.
Conclusions The issue of ethyl carbamate in alcoholic beverages is a cause of widespread public concern. Thus, the upper limit of EC in alcoholic beverages set by Canada has been adopted by many other countries. There were few reports from China concerning EC in alcoholic beverages, which highlights the need for studies on its detection and control in alcoholic beverages and other fermented foods to protect consumer health. Moreover, it is urgent to establish our own MALs for EC based on Chinese consumption patterns and set an acceptable daily intake (ADI).
Acknowledgements We thank Shijiazhuang CDC, Baoding CDC, Handan CDC, Qinhuangdao CDC, Langfang CDC, Zhangjiakou CDC, Xingtai CDC and Cangzhou CDC for providing samples.
References Beland FA, Wayne BR, Mellick PW, Kovatch RM, Roberts DW, Fang JL, Doerge DR. 2005. Effect of ethanol on the tumorigenicity of urethane (ethyl carbamate) in B6C3F1 mice. Food Chem Toxicol. 43:1–19. Canas BJ, Joe Jr FL, Diachenko GW, Burns G. 1994. Determination of ethyl carbamate in alcoholic beverages and soy sauce by gas chromatography with mass selective detection: collaborative study. J AOAC Int. 77:1530–1536. Fu ML, Liu J, Chen QH, Liu XJ, He GQ, Chen JC. 2010. Determination of ethyl carbamate in Chinese yellow rice wine using high-performance liquid chromatography with fluorescence detection. Int J Food Sci Technol. 45: 1297–1302. Ha MS, Hu SJ, Park HR, Lee HM, Kwon KS, Han EM, Kim KM, Ko EJ, Ha SD, Bae DH. 2006. Estimation of Korean adult’s daily intake of ethyl carbamate through Korean commercial alcoholic beverages based on the monitoring. Food Sci Biotechnol. 15:112–116. Hasnip S, Crews C, Potter N, Christy J, Chan D, Bondu T, Matthews W, Walters B, Patel K. 2007. Survey of ethyl carbamate in fermented foods sold in the United Kingdom in 2004. J Agric Food Chem. 55:2755–2759. Hong KP, Kang YS, Jung DC, Park SR, Yoon JH, Lee SY, Ko YS, Kim SH, Ha SD, Park SK, et al. 2007. Exposure to ethyl carbamate by consumption of alcoholic beverages imported in Korea. Food Sci Biotechnol. 16:975–980. Lachenmeier DW, Kanteres F, Kuballa T, Lo´pez MG, Rehm J. 2009. Ethyl Carbamate in Alcoholic Beverages
Food Additives and Contaminants: Part B from Mexico (Tequila, Mezcal, Bacanora, Sotol) and Guatemala (Cuxa): Market Survey and Risk Assessment. Int J Environ Res Public Health. 6: 349–360. Lachenmeier DW, Nerlich U, Kuballa T. 2006. Automated determination of ethyl carbamate in stone-fruit spirits using headspace solid-phase microextraction and gas chromatography–tandem mass spectrometry. J Chromatogr A. 1108:116–120. Lachenmeier DW, Schehl B, Kuballa T, Frank W, Senn T. 2005. Retrospective trends and current status of ethyl carbamate in German stone-fruit spirits. Food Addit Contam A. 22:397–405. Ma YP, Deng FQ, Chen DZ, Sun SW. 1995. Determination of ethyl carbamate in alcoholic beverages by capillary multidimensional gas chromatography with thermionic specific detection. J Chromatogr A. 695:259–265. Park SR, Ha SD, Yoon JH, Lee SY, Hong KP, Lee EH, Yeom HJ, Yoon NG, Bae DH. 2009. Exposure to ethyl carbamate in alcohol-drinking and nondrinking adults and
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its reduction by simple charcoal filtration. Food Control. 20:946–952. Perestrelo R, Petronilho S, Camara JS, Rocha SM. 2010. Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry combined with solid phase microextraction as a powerful tool for quantification of ethyl carbamate in fortified wines. The case study of Madeira wine. J Chromatogr A. 1217: 3441–3445. Uthurry CA, Varela F, Colomo B, Sua´rez Lepe JA, Lombardero J, Garcı´ a del Hierro JR. 2004. Ethyl carbamate concentrations of typical Spanish red wines. Food Chem. 88:329–336. Weber JV, Sharypov VI. 2009. Ethyl carbamate in foods and beverages: a review. Environ Chem Lett. 7:233–247. Zhou PP, Zhao YF, Zhang G, Wu YN. 2007. Determination of ethyl carbamate in wine by stable isotope dilution gas chromatography/mass spectrometry. Chin J Food Hyg. 19:492–495.
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VIEW DATASET Ethyl carbamate levels in wine and spirits from markets in Hebei Province, China Y.P. Liua, B. Donga, Z.S. Qina, N.J. Yanga, Y. Lua, L.X. Yanga, F.Q. Changa* and Y.N. Wub a
Institute of Physical and Chemical Inspection, Hebei Center for Disease Control and Prevention, Shijiazhuang, China; bNational Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China (Received 28 September 2010; final version received 22 January 2011) Ethyl carbamate (EC) in wine, grain spirits and wine sauce (145 samples) was analysed using solid-phase extraction and stable isotope dilution GC/MS. Samples were obtained from markets in eight areas (Shijiazhuang, Baoding, Handan, Qinhuangdao, Langfang, Zhangjiakou, Xingtai and Cangzhou) of Hebei Province, China. The method had a limit of detection of 2 mg kg1, with recoveries varying from 95.7 to 102% and RSD ranging 2.3–5.6%. The average concentrations of ethyl carbamate in wines, grain spirits and wine sauce were 14.7 (52.0– 44.5) mg kg1, 33.8 (2.9–129) mg kg1 and 8.7 (52.0–63.3) mg kg1, respectively. The results led to the development of limit standards that can be used to predict the concentration of ethyl carbamate in Chinese fermented wines. Keywords: alcoholic beverages; process contaminants; ethyl carbamate
Introduction Ethyl carbamate (EC) occurs in most fermented beverages at levels ranging from ng l1 to mg l1 (Beland et al. 2005; Park et al. 2009; Weber and Sharypov 2009). In 1985, high levels of ethyl carbamate were detected in alcoholic beverages in Canada. Consequently, maximum allowable limits (MALs) of ethyl carbamate in wines were set at 30 and 150 mg l1 for grain spirits by the Canadian authorities in the same year. In 2007, the International Agency for Research on Cancer (IARC) assessed ethyl carbamate as ‘‘probably carcinogenic to humans’’ and proposed a maximum daily intake of 0.3 mg kg1 bw (body weight). Fortunately, the issue of EC in alcoholic beverages has attracted a great deal of attention in many countries and reliable methods already exist for analysis of EC, such as GC/MS (Lachenmeier et al. 2005; Park et al. 2009) and GC/MS/MS (Lachenmeier et al. 2006). There are also extensive sample preparation steps; for example, liquid–liquid extraction (LLE), solid phase micro-extraction and solid phase extraction (Ma et al. 1995; Lachenmeier et al. 2009; Weber and Sharypov 2009; Perestrelo et al. 2010). To the best of our knowledge, however, very little data is available on the levels of EC in alcoholic beverages in China. Moreover, no guidelines or regulations yet exist relating to ethyl carbamate in China. In the present study, a large number of samples were
*Corresponding author. Email: [email protected] ISSN 1939–3210 print/ISSN 1939–3229 online ß 2011 Taylor & Francis DOI: 10.1080/19393210.2011.557783 http://www.informaworld.com
analyzed for EC using the official method, namely SPE combined with GC/MS (Canas et al. 1994). The focus of the study was to contribute data for the Chinese authorities to enable them to establish maximum limits for ethyl carbamate in China.
Materials and methods Samples A total of 145 samples were obtained from local markets between May and August 2010 in eight areas (Shijiazhuang, Baoding, Handan, Qinhuangdao, Langfang, Zhangjiakou, Xingtai and Cangzhou) of Hebei Province (China); all were domestic alcoholic beverages. The samples include 48 grain spirits, 57 wines and 40 wine sauces.
Chemicals All solvents were HPLC-grade and purchased from JT Baker (Philipsburg, PA, USA). The Celite diatomaceous earth columns (CARB/NH2, 500 mg/500 mg/ 6 ml) were provide by Hangzhou Fuyu Technology Service Company Limited. The EC standard (99%) was from Sigma-Aldrich (Madrid, Spain). The d5-EC standard (99%) was from Cambridge Isotope Laboratory (Andover, MA, USA).
2
Y.P. Liu et al. Table 1. Recoveries and relative standard deviations (RSDs) for EC. Determined times 1 2 3 1 2 3
Spiking level (mg kg1)
Determined result (mg kg1)
Recovery (%)
37.2 37.2 37.2 186 186 186
33.3 36.5 37.0 185.6 189 194
89.5 98.1 99.4 99.7 102 104.3
Sample pretreatment A liquid sample of 2.0 g was homogenised with 100 ml d5-EC solution (1 mg ml1) as internal standard, and then subjected to SPE column. After an equilibration time of 15 min, 5 ml hexane was used to pre-rinse the column. Next, the analytes were extracted using 10 ml ethyl ether. The eluate was concentrated to dryness under nitrogen gas and re-dissolved in 1 ml of methanol before GC/MS analysis.
GC/MS method The GC/MS system used for analysis was a Thermo Trace-GC in combination with an ultra-DSQ mass spectrometer. A HP-INNOWAX capillary column (30 m 0.25 mm0.25 mm film thickness) was used. The primary oven temperature was programmed from 60 C (3 min) to 160 C (2 min) at 8 C min1, with a post-run temperature of 240 C for 5 min. The injection port was 200 C. Helium was used at a constant flow of 1 ml min1. The MS transfer line temperature was 250 C and the MS source temperature was 230 C. The MS was operated in EI mode at 70 eV. Acquisition was performed in selected ion monitoring mode and m/z 44, 62, 64, 76 and 89 were recorded. For quantitative analysis, m/z 64 for ethyl carbamate-d5 and m/z 62 for ethyl carbamate were chosen. Ion ratios for the EC standard were m/z 62 (100%), m/z 44 (97%) and m/z 89 (5%) and, for d5-EC standard, were m/z 64 (100%), m/z 44 (90%), m/z 76 (20%) and m/z 89 (10%). Confirmation criteria for the identification and quantification of EC include the following: (a) retention time for all m/z monitored for a given analyte should maximize simultaneously 0.2 min, with S/N 3 for each; (b) in all m/z monitored, at least of two ions, the ratio between the two monitored ions should be within 20% of the standard.
Average recovery (%)
RSDs (%)
95.7
5.6
102
2.3
Quality control A five-point calibration curve of EC was created for quantification concentrations: 8.55, 17.1, 51.3, 102.6 and 205.2 mg l1. A high correlation coefficient (r2 ¼ 0.9999) was obtained for the tested interval. Method reproducibility studies were investigated by injecting three replicates of the same standard solution on three different days and on the same day. Both the intra- and inter-day precision showed relative standard deviations (RSDs) below 15%. The recoveries of ethyl carbamate were obtained by analysis of 2.0 g spiked and non-spiked cooking wine, with two spiking levels of 37.2 and 186 mg l1. As shown in Table 1, average recoveries of EC were 95.7 and 102% at the two levels, respectively. The RSD (n ¼ 3) ranged from 5.6 to 2.3%. The limit of detection (LOD) was obtained using standards containing the compounds of interest at low concentration levels at a signal-to-noise ratio of 3. The LOD and LOQ (normally based on S/N ¼ 10) of the present method were 2 and 8 mg kg1, respectively.
Results and discussion As listed in Tables 2–4, the average level of EC in grain spirits was 33.8 mg kg1 (2.9–129 mg kg1), and 14.7 mg kg1 (52.0–44.5 mg kg1) and 8.3 mg kg1 (52.0–63.3 mg kg1), in wines and wine sauce, respectively. The concentrations of EC in grain spirits were clearly higher than in either wines or wine sauce (Figure 1). EC was detected in all grain spirits and wines, but the content in grain spirits were below international guideline levels (150 mg l1). However, higher levels of EC were detected in a minority of grain spirits (90– 129 mg kg1). In the case of wines, about 15% of the alcoholic beverages exceeded the international limit (30 mg l1). In addition, about 88% of wine sauces were below 10 mg kg1, and EC was not detected in many of them. Although EC levels in grain spirits were not particularly high, this may be an important source of EC due to its high consumption.
Food Additives and Contaminants: Part B
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Table 2. EC levels in grain spirits from eight areas of Hebei Province, China (mg kg1). Samples 1 2 3 4 5 6 7 8 9 Average contents
S
Q
B
H
L
Z
X
C
Total average contents
19.5 4.7 2.9 5.8 21.2 16.8 31.1 10.4 19.9 14.7
24.9 36.1 24.9 49.2 92.7 – – – – 45.6
16.3 7.4 16.7 16.4 7.5 – – – – 12.9
34.1 10.6 91.7 22.1 40.9 – – – – 39.9
42.5 18.7 16.1 14.5 8.6 – – – – 20.1
56.8 43.5 30.2 20.1 22.9 – – – – 34.7
55.1 8.56 27.5 30 117.2 23.6 28.6 41.4 15.1 38.6
72.3 34.6 30.7 51.9 129 – – – – 63.7
33.8
Note: –, no samples; S, Shijiazhuang; Q, Qinhuangdao; B, Baoding; H, Handan; L, Langfang; Z, Zhangjiakou; X, Xingtai; C, Cangzhou.
Table 3. EC levels in wines from eight areas of Hebei Province, China (mg kg1). Samples 10 11 12 13 14 15 16 17 18 19 Average contents
S
Q
B
H
L
Z
X
C
Total average contents
9.3 9.2 6.9 26.7 31.8 9.4 8.3 20.1 18.9 14.4 15.5
10.2 10.5 12.4 15.2 4.5 52.0 4.3 6.3 7.1 9.2 8.2
22.1 6.9 12.8 10.7 28.4 6.1 8.0 – – – 13.6
12.4 5.1 14.7 6.1 10.3 – – – – – 9.7
16.8 52.0 2.5 3.3 10.2 – – – – – 7.0
7.3 9.2 15.6 5.5 5.4 – – – – – 8.6
7.7 32.1 32.9 44.5 32.0 17.5 18.3 16.6 16.3 13.8 23.2
31.7 33.8 36.5 25.5 31.8 – – – – – 31.9
14.7
Note: –, no samples; S, Shijiazhuang; Q, Qinhuangdao; B, Baoding; H, Handan; L, Langfang; Z, Zhangjiakou; X, Xingtai; C, Cangzhou.
Table 4. EC levels in wine sauce from eight areas of Hebei Province, China (mg kg1). Samples 20 21 22 23 24 Average contents
S
Q
B
H
L
Z
X
C
Total average contents
21.2 8.3 11.1 9.9 5.6 11.2
5.4 3.4 4.5 3.7 3.6 4.2
52.0 2.9 52.0 4.0 3.3 2.2
4.7 2.8 2.7 4.3 63.3 15.6
52.0 52.0 52.0 2.7 3.4 1.4
6.5 52.0 52.0 52.0 52.0 1.6
3.2 3.7 42.1 46.1 29.5 24.9
4.8 4.7 5.0 4.3 7.5 5.3
8.3
Note: S, Shijiazhuang; Q, Qinhuangdao; B, Baoding; H, Handan; L, Langfang; Z, Zhangjiakou; X, Xingtai; C, Cangzhou.
Comparing the areas sampled, high EC levels (490 mg kg1) were detected in some grain spirits from Qinhuangdao, Handan, Xingtai and Cangzhou. In several wines from Shijiazhuang, Baoding, Xingtai and Cangzhou, EC levels ranged 30–45 mg kg1. Thus, both grain spirits and wines from Cangzhou showed the highest mean levels. It should also be pointed out that the mean level in wines from Cangzhou was a little
higher than the international limit (30 mg l1), with a mean value of 31.9 mg kg1. Additionally, relatively higher concentrations in wine sauce were found in most Xingtai samples, with a level of 25 mg kg1 on average; however, the highest level in wine sauce was obtained in the Handan samples (63.3 mg kg1). The incidence of ethyl carbamate in wines (52.0–44.5 mg kg1) are in close agreement with
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Y.P. Liu et al.
Average content (mg kg–1)
70 60 50 Grain spirits
40
Wines 30
Wine sauce
20 10 0 S
Q
B
H
L
Z
X
C
S–Shijiazhuang, Q–Qinhuangdao, B–Baoding, H–Handan, L–Langfang, Z–Zhangjiakou, X–Xingtai, C–Cangzhou. Figure 1. Average contents of ethyl carbamate in fermented wines from eight areas of Hebei Province, China (mg kg1).
levels in 56 wines (6.0–55.4 mg kg1) reported by Zhou et al. (2007). However, the results are higher than those published elsewhere (Uthurry et al. 2004; Hasnip et al. 2007; Hong et al. 2007). In the UK in 2004. Hasnip et al. (2007) showed that seven European wines contained EC at levels between 11 and 24 mg kg1. A survey in Korea (Hong et al. 2007) showed that EC in wines was 1.7–11.7 mg kg1. Uthurry et al. (2004) analyzed EC in typical Spanish red wines, with results below 25 mg kg1 or at undetected level. Contamination of grain spirits by EC (2.9– 129 mg kg1) in this study was much higher than two similar surveys in Korea (Ha et al. 2006; Hong et al. 2007), with levels of 7–9.5 and 0.8–10.1 mg l1, respectively Our results of EC in wine sauce (52.0– 63.3 mg kg1) were also higher than those reported by Ha et al. (2006) (0.4–0.9 mg l1). However, levels considerably above this, up to 242 mg kg1, have been reported by Fu et al. (2010) in Chinese yellow rice wines.
Conclusions The issue of ethyl carbamate in alcoholic beverages is a cause of widespread public concern. Thus, the upper limit of EC in alcoholic beverages set by Canada has been adopted by many other countries. There were few reports from China concerning EC in alcoholic beverages, which highlights the need for studies on its detection and control in alcoholic beverages and other fermented foods to protect consumer health. Moreover, it is urgent to establish our own MALs for EC based on Chinese consumption patterns and set an acceptable daily intake (ADI).
Acknowledgements We thank Shijiazhuang CDC, Baoding CDC, Handan CDC, Qinhuangdao CDC, Langfang CDC, Zhangjiakou CDC, Xingtai CDC and Cangzhou CDC for providing samples.
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