浙江省不同地理尺度有机茶稳定同位素特征差异分析

Analysis of Stable Isotope Characteristics of Organic Tea at Different Geographical Scales in Zhejiang Province

为探究浙江省有机茶稳定同位素特征差异,本研究收集了来自浙江省52个有机茶企业生产的72份具有代表性的样品,采用元素分析-稳定同位素比率质谱仪测定有机茶中稳定同位素比值(δ^(15)N、δ^(13)C、δ^(2)H、δ^(18)O值),研究不同茶类间的稳定同位素差异,并从3个地理尺度对浙江省有机茶稳定同位素特征进行分析。结果表明,浙江省有机绿茶和有机红茶的稳定同位素比值无显著差异。浙江省有机茶δ^(15)N值范围为-2.4‰~6.7‰,平均值为2.0‰,在地市尺度上无显著差异;在区域尺度上,浙南地区有机茶δ^(15)N显著高于浙北地区;在全国尺度上,浙江省有机茶δ^(15)N显著高于全国其他产区。浙江省有机茶δ^(13)C、δ^(2)H、δ^(18)O平均值分别为-27.2‰、-47.9‰、26.3‰,部分地市间存在地域差异,浙南地区和浙北地区有机茶的3种稳定同位素比值均无显著差异。本研究为浙江省有机茶稳定同位素数据库建立及特征识别提供了科学依据。

To explore the difference of stable isotope characteristics of organic tea in Zhejiang Province,72 representative samples from 52 organic tea enterprises in Zhejiang Province were collected.The stable isotope ratios(δ^(15)N,δ^(13)C,δ^(2)H,δ^(18)O)in organic tea were determined by elemental analysis-stable isotope ratio mass spectrometer,the differences in stable isotopes between different tea species was studied,and the stable isotope characteristics of organic tea in Zhejiang Province were analyzed from three geographical scales.The results showed that there was no significant difference in the stable isotope ratio between organic green tea and organic black tea.Theδ^(15)N of organic tea in Zhejiang Province ranged from^(-2).4‰to 6.7‰,with an average value of 2.0‰,and there was no significant difference at the city scale.At the regional scale,δ^(15)N of organic tea in southern Zhejiang was significantly higher than that in northern Zhejiang.At the national scale,theδ^(15)N of organic tea in Zhejiang Province was significantly higher than that in other producing areas in China.The mean values ofδ^(13)C,δ^(2)H andδ^(18)O of organic tea in Zhejiang Province were-27.2‰,-47.9‰and 26.3‰,respectively,and there were regional differences among some cities.There was no significant difference in the three stable isotope ratios of organic tea between southern and northern Zhejiang.This study provided a scientific basis for the establishment and characterization of stable isotope database of organic tea in Zhejiang Province.