锶同位素分析及其在葡萄酒产地鉴别中的应用

Strontium isotope analysis and its application in identifying the geological origin of wines

中文关键词:  锶  同位素  葡萄酒  产地鉴别

英文关键词:strontium  isotope  wine  identification of geological origin

中文摘要:

      目的 研究确定最佳的锶同位素分析技术, 分析不同产区葡萄酒中锶同位素组成, 通过统计手段, 直观展示锶同位素用于葡萄酒产地鉴别的可靠性。方法 本研究首先通过葡萄酒中锶同位素国际比对CCQM P105比较、确认多接收电感耦合等离子体质谱法(multi-collector inductively coupled plasma mass spectrometry, MC-ICP-MS)和热电离同位素质谱法(thermal ionization mass spectrometry, TIMS)的准确性, 确定采用TIMS分析79种葡萄酒中锶同位素数据, 以K-平均值算法进行统计分析, 展示大产区、小产区的δ87Sr。结果 1) TIMS是最佳的葡萄酒中锶同位素分析方法: (1) 87Rb信号残留比为1/1000时, 影响锶同位素测量的准确性。采用TIMS, 在1000 ℃下加热10 min, Rb的干扰可以完全消除; (2)采用86Sr/88Sr=(0.1194±0)内标法校正质量歧视, 对测量结果有影响, 外标法获得的结果更准确; 2)各产区葡萄酒中锶同位素组成具有明显的地域特征: 新疆产区δ87Sr偏负, 甘肃、宁夏产区具有正的δ87Sr; 3)锶同位素鉴别葡萄酒产地的总体正确率达到91%以上, 石河子、巴州、焉耆、五家渠、哈密5个新疆域内小产区的判别正确率达到100%。结论 TIMS可以通过测量程序进一步消除残留87Rb的干扰, 对样品分离要求低, 所测结果的准确性更可靠; 统计分析表明, 锶同位素技术具有良好的葡萄酒产地鉴别能力, 而且具有较好的地理分辨力, 是食品产地追溯的有效手段。但部分产区葡萄酒的鉴别效果不佳, 也说明单一的鉴别技术具有局限性, 大数据基础上的多维分析技术是食品真实性鉴别领域的发展方向。

英文摘要:

      Objective To explore the best strontium isotope analysis technology, then analyze the strontium isotope compositions of wines in different geological origins, and visually demonstrate the reliability of strontium isotope technology used in wine origin identification by statistical means. Methods First, multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) and thermal ionization mass spectrometry (TIMS) were investigated by the international comparison, CCQM P105. The strontium isotope data of 79 wines were determined by TIMS, and statistical analysis was performed using K-means cluster to show δ87Sr in large and small producing areas. Results 1) TIMS was the best method for strontium isotope analysis in wine: (1) when the signal residual ratio of 87Rb was 1/1000, the accuracy of strontium isotope measurement was affected. Using TIMS, heating at 1000 ℃ for 10 min, Rb interference could be completely eliminated; (2) the internal correction method of 86Sr/88Sr=(0.1194±0) was rejected to correct the mass discrimination, which had an effect on the measurement results, the result obtained by the external correction method was most accurate; 2) the Sr isotope compositions of wines from different regions had obvious regional characteristics: δ87Sr in Xinjiang was negative, while it was positive in Gansu and Ningxia; 3) the overall correct rate of Sr isotope identification for wine producing areas was above 91%, and that of Shihezi, Bazhou, Yanqi, Wujiaqu and Hami, 5 small wine producing areas in Xinjiang, was even 100%. Conclusion TIMS can further remove the interference of residual 87Rb by measuring program, which has low requirements for sample separation and more reliable accuracy of measured results; statistical analysis show that strontium isotope technology has a good ability to identify wine origin and good geographical resolution, which is an effective means to trace geological origins. The poor identification effect of some local wines also shows that single identification technology has limitations, and multidimensional analysis technology based on big data is the development direction of food authenticity identification.