15N稳定同位素标记集胞藻的生物合成研究

目的建立实验室生物合成15N稳定同位素标记集胞藻的最优培养条件,并驯化得到高丰度15N集胞藻藻种。方法对培养温度、光照及p H值等条件进行优化,优选出最佳培养工艺。将培养基中的14N氮源替换为15N氮源,优化配方,使用同位素比质谱仪测量藻体中15N、14N同位素组成。结果实验室培养条件选定为培养温度25℃、光照强度2000 lux、初始p H值为7时,集胞藻生长良好。将配方中硝酸钠浓度设定为1.5 g/L时,产品丰度最大。驯化得到高丰度15N-集胞藻藻种。结论本试验优化的培养工艺和配方,适宜15N稳定同位素标记集胞藻生长。得到的藻种产品丰度高,生产成本低。     

国内外稳定同位素技术在肉品溯源中应用的现状

为进一步探索和明确稳定同位素技术在我国肉品溯源中应用的不足和未来研究发展方向,本文通过对当前国内外稳定同位素技术应用于食品尤其是肉制品产地溯源检测中的研究进展进行了总结,列举了可应用于肉制品溯源检测的主要同位素元素种类,指出了其来源和含量影响因素,分析了将该技术应用于肉制品产地溯源的技术关键及其可行性。      

稳定同位素技术在动物性产品溯源体系中的研究进展

稳定同位素技术因其没有放射性,不会对人体造成伤害,又具有灵敏准确的优点,可用于鉴别不同产地、不同食源的动物性产品,成为追溯食品产地来源的一种有效工具,具有广阔的应用前景。文中系统阐述了稳定同位素技术在动物性产品如肉类、奶制品等的真实性和可追溯性国内外研究进展,以期为相关学者的研究提供帮助,同时也为我国农产品溯源体制的建立提供借鉴。     

Study on distribution pattern of stable carbon isotope ratio of Chinese honeys by isotope ratio mass spectrometry

The δ ¹³C values of 26 varieties of Chinese pure single‐flower honeys, 323 census samples of six varieties of single‐flower honeys and one multi‐flower honey as well as 20 888 commercial honey samples from 135 honey‐related enterprises in 25 provinces of China were analysed by stable carbon isotope ratio mass spectrometry between 1998 and 2004. It was found that the δ ¹³C values of different Chinese honeys fell within the ranges of values proposed by JW White. This shows that White's theory of the stable carbon isotope ratio of honeys is applicable to Chinese honeys and further demonstrates that the theory is universal to honeys from all over the world. The study also confirmed that the δ ¹³C values of honeys do not bear much relation to the environment in which the honey plants are grown, e.g. geographical area, water and soil, climate, etc., but do vary slightly with the honey plant species. Copyright © 2005 Society of Chemical Industry     

基于稳定氢氧同位素技术的花生油掺假检测技术研究

建立了高温裂解/元素分析-稳定同位素比值质谱联用技术（TC/EA-IRMS）测定油脂稳定氢氧同位素比值（δ2H和δ18O）的方法,并根据氢氧同位素特征开展花生油掺假检测技术研究。对28个花生样品、5个大豆样品和6个油菜籽样品榨油后测定δ2H值和δ18O值,结果发现三种油的δ2H值分布范围分别为-231.50‰~-213.69‰、-183.11‰~-169.53‰和-192.17‰~-175.82‰;δ18O值分布范围为14.06‰~16.77‰、19.77‰~20.98‰和24.31‰~27.45‰;其中花生油的δ2H值与大豆油和菜籽油存在显著性差异（p＜0.01）,模拟实验表明根据氢氧同位素特征可检测花生油中掺入大豆油或菜籽油。通过对氢氧同位素比值的二维分布对比,可以更为全面的评价和鉴别花生油的掺杂掺假情况,为花生油的掺假鉴别提供了研究基础和技术支持。     

稳定氢同位素在出口罗非鱼产地溯源中的应用

探索稳定性氢同位素对中国出口罗非鱼产地溯源的可行性。利用同位素比率质谱仪测定来自广东、海南、广西、福建4个地域来源的罗非鱼组织(腹肉和背肉)中δ2 H值。比较分析不同产地来源的罗非鱼组织中氢同位素组成的差异,及其与地域经度、纬度变化的关系,以及稳定性氢同位素用于罗非鱼产地溯源的可行性。结果表明,不同地域的罗非鱼组织中δ2 H同位素组成有显著差异(P<0.05);罗非鱼背肉与腹肉中δ2 H值有显著的相关性;罗非鱼肉中的δ2 H值有随着地理纬度增加而减小的趋势;以δ2 H同位素为指标,对罗非鱼肉产地的正确判别率高达85%。δ2 H同位素是罗非鱼产地溯源的一项很有潜力的指标。     

基于稳定性同位素技术的水果及其制品产地溯源研究进展

随着我国社会主义市场经济的不断发展, 果品贸易飞速发展, 在软饮料行业中占有举足轻重的地位。但欺瞒消费者果品原产地事件仍然存在, 为了保护各地的优质产品不受影响、保障消费者的合法权益不受侵害以及出现问题时能够快速准确的实施相应的补救措施, 建立一套健全的质量安全全程可追溯体系是必不可少的。本文基于国内外学者对水果及其制品的产地溯源研究进展, 综述了现有技术的基本原理、特点、局限性及应用现状, 重点阐述了稳定同位素技术原理、不同元素的应用特点、主要分析仪器以及在果品产地溯源应用研究现状, 并对该技术的应用前景进行了展望。     

利用稳定同位素进行农产品产地溯源和真伪鉴别研究进展

产地溯源是保护产品原产地信息及以假乱真等农产品安全问题的有效保障, 而稳定同位素溯源技术具有高精准的示踪及溯源能力, 是农产品产地溯源的有效手段, 该技术在国内外已有显著成果。基于这些研究成果, 本综述归纳了近5年(2018—2022年)农产品中轻、重元素稳定同位素在产地溯源和真伪鉴别方面的应用进展, 阐述了稳定同位素与其他技术相结合溯源的研究, 并依据判别结果得出结论: 增加采样数量、扩大采样范围、筛选有效溯源指标、选取适当的化学计量学方法, 同时利用多种分析技术融合鉴别, 从而提高溯源正确率, 完善农产品溯源体系, 为稳定同位素今后的研究提供参考。     

稳定同位素比质谱法鉴别焦亚硫酸钠处理大蒜

目的 基于硫稳定同位素比质谱法鉴别焦亚硫酸钠处理的大蒜。方法 通过收集全国主要食品级商家的焦亚硫酸钠与山东、黑龙江和辽宁三省大蒜,比较δ³⁴S值的分布差异,进而开展焦亚硫酸钠模拟浸泡实验以获得大蒜硫同位素的比值变化(Δδ³⁴S)。结果 焦亚硫酸钠的δ³⁴S值分布在-2.0‰～2.0‰和4.0‰～12.0‰两个区间。山东、黑龙江、辽宁三省大蒜δ³⁴S范围分别为1.0‰～8.2‰、1.3‰～6.5‰和1.7‰～6.3‰,东北两省大蒜硫同位素值均小于8.0‰。采用δ³⁴S值为10.6‰的焦亚硫酸钠浸泡东北大蒜,浸泡前后?δ³⁴S发生显著变化。未剥皮组大蒜在质量浓度为5～100 g/L时,?δ³⁴S基本不变,约为1.0‰;剥皮组大蒜在质量浓度为0～20 g/L范围内,?δ³⁴S逐渐升高,在质量浓度为20～100 g/L时,?δ³⁴S基本不变,其值约为1.8‰。结论 硫稳定同位素比质谱法可鉴别焦亚硫酸...     

基于稳定同位素比值的不同产地枸杞特征分析及判别

原产地差异导致枸杞价格悬殊,为促进国内枸杞市场健康有序发展,该文应用元素分析仪-稳定性同位素质谱（elemental analyzer-stable isotope mass spectrometry, EA-IRMS）测定了来自青海、宁夏和新疆3个地区共97份枸杞样品δ¹³C、δ¹⁵N、δ²H、δ¹⁸O和δ³⁴S 5种稳定同位素组成,结合箱线图、单因素方差分析以及主成分分析（principal component analysis, PCA）对不同产地枸杞中稳定同位素比值分布规律和相关性进行了讨论,应用线性判别分析（linear discriminant analysis, LDA）和支持向量机（support vector machine, SVM）2种算法建立不同产地枸杞判别模型。结果显示,枸杞样品中δ¹³C、δ¹⁵N、δ²H和δ¹⁸O 4种稳定同位素对产地判别贡献率较大,δ^...     

基于稀土元素和稳定同位素指纹的枸杞道地性表征

【目的】本研究旨在探讨稀土元素结合碳氮稳定同位素在枸杞原产地判别中的可行性,为枸杞地理标志产品保护提供技术支撑。【方法】采集宁夏、甘肃、青海和新疆5个产区共222份枸杞样本,利用电感耦合等离子体质谱(ICP-MS)及元素分析-稳定同位素比值质谱仪（EA-IRMS）测定枸杞中14种稀土元素及碳、氮稳定同位素比值,结合化学计量学方法分析了监测指标在枸杞成熟阶段中的变化规律,并构建了枸杞产地判别模型。【结果】La、Nd、Sc、Nd、Dy、Gd、Sm、Eu、Tb、Ho、Tm、δ13C、δ15N在枸杞成熟过程中具有显著变化,随着枸杞成熟,稀土元素及碳氮稳定同位素具有明显的变化规律;11种稀土元素在4个枸杞产区间存在显著差异,δ13C、δ15N在部分产区间存在显著差异;主成分分析可提取出5个主成分,前2个主成分可有效区分新疆、青海的枸杞样品,宁夏和甘肃的样品不能有效区分;采用Fisher线性判别分析方法构建了基于La、Nd、Sc、Y、Pr、Eu、Yb、Dy、Gd、Tb、Ho、Tm、δ13C、δ15N 14个指标的枸杞产地判别模型,判别模型正确判别率在90.1%以上。【结论】基于稀土元素和碳、氮稳定同位素指纹的差异可以有效鉴别不同产地的枸杞。     

稳定氢氧同位素鉴别非还原（NFC）橙汁真实性应用初探

利用稳定同位素比值质谱仪（IRMS）测定橙汁水中δD和δ^18O,结果表明非还原（NFC）橙汁水中δD和δ^18O要明显高于地下水;橙汁蒸发浓缩后会富集D和^18O,但加水还原后产品水中δD和δ^18O均低于原橙汁,且产品水中δD和δ^18O与加水量呈负相关性关系,可用于鉴别还原（FC）橙汁和非还原（NFC）橙汁。     

稳定同位素技术在饮料酒掺杂和溯源检测的应用

稳定同位素技术可以有效地应用于饮料酒的掺杂和溯源检测。建立高效的饮料酒产地溯源体系是保证食品质量安全的重要手段。文章在国内外饮料酒掺杂和溯源研究的基础上,综述了稳定同位素技术的基本原理以及其在国内外饮料酒掺杂和溯源检测领域中的应用研究进展,展望了稳定同位素技术在我国饮料酒掺杂和溯源中的应用前景。旨在为未来我国白酒掺杂和溯源方面研究提供理论指导和方法参考。     

基于矿物元素和稳定同位素技术不同产地陈皮鉴别研究

为开展不同产地陈皮中矿物元素含量和稳定同位素比值的影响,并建立产地溯源模型,采集我国4个地区(广东、福建、四川和重庆)共160份陈皮样品,用电感耦合等离子体质谱法测定陈皮中21种矿物元素的含量,用元素分析质谱法测定陈皮中4种稳定同位素比值,研究不同产地陈皮中矿物元素含量、稳定同位素比值差异并进行产地溯源。结果表明,除Zn外,其余20种矿物元素的含量、4种稳定同位素的比值在4个地区间均存在显著差异(P＜0.05) ,陈皮样品中含量最高的是K,其次是Ca,最低的是Y。对160个陈皮样品的矿物元素含量和稳定同位素比值进行主成分分析法(PCA)、偏最小二乘判别分析法(PLS-DA)、正交偏最小二乘判别分析法(OPLS-DA)和交叉验证的结果表明,矿物元素、稳定同位素可以对不同产地来源的陈皮样品进行鉴别,线性判别(LDA)交叉验证准确率为93.8%,通过VIP值筛选得出产地鉴别的关键因子是Cu、K、Ga、Ni、Y、Ba、La、Nd、V、Cr、Rb、Fe、Mn、Co及δ18^O。综上,利用矿物元素结合稳定同位素技术可以有效地鉴别陈皮的地理来源,这项技术的应用可以为判断陈皮的产地和真实性提供可靠的技术支持。     

食品中甲醛的稳定碳同位素特征分析及其在甲醛源解析中的应用

采用衍生化—气相色谱—燃烧—同位素比质谱法(Gas Chromatography-Combustion-Isotope Ratio mass Sprectrometry,GC/C/IRMS)对水产品、蔬菜制品、果蔬的甲醛含量和δ13 C值进行了测试.结果表明,鱿鱼样品中甲醛含量为0.341～24.185 mg/kg,δ...     

基于稳定同位素比率和矿质元素含量分析的进口大豆产地溯源

目的探索稳定同位素比率和矿质元素含量分析用于进口大豆溯源的可行性。方法采用稳定同位素质谱测定阿根廷和巴西大豆中的4种轻元素碳、氮、氢、氧的稳定同位素比率,采用电感耦合等离子体质谱测定大豆中的38种矿质元素含量,对结果进行方差分析,并运用正交偏最小二乘法判别分析构建大豆产地判别模型。结果大豆的碳、氮、氢、氧稳定同位素比率(δ~(13)C、δ~(15)N、δ~2H、δ~(18)O)和镁、铝、钪等26种矿质元素含量具有明显的地域差异,结合多元统计学方法,可以有效地区分阿根廷和巴西所产的大豆,交叉验证的判别准确率均达到了100%。结论稳定同位素比率和矿质元素含量分析结合多元统计学方法可对阿根廷和巴西大豆进行有效的产地溯源,具有较大的应用前景,有望为进口大豆产地溯源技术的研究提供新的方法。     

Correlation between multielement stable isotope ratio and geographical origin in Peretta cows' milk cheese

The aim of this study was to characterize the isotopic composition and protect “Peretta” cows’ milk cheese, a typical product of Sardinia, against other cheeses of the same appearance sold under the same name, but made of raw materials from northern Europe. The study was concerned with 3 types of cheese: those produced in local dairies from milk from free-grazing or pasture-grazing cows in Sardinia (local dairy product), cheeses made on an industrial scale from milk produced by intensive farming in Sardinia (factory cheese), and cheeses made with raw materials imported from other countries (imported product). To distinguish the Sardinian cheeses from the imported product, the stable isotope ratios ¹³C/¹²C, ¹⁵N/¹⁴N, D/H, ³⁴S/³²S, and ¹⁸O/¹⁶O were used. Determination of the isotopic data δ¹³C, δ¹⁵N, δ²H, and δ³⁴S was performed in the casein fraction, whereas δ¹⁸O and δ¹³C were determined in the glycerol fraction. Measurements were performed by isotope ratio mass spectrometry. A comparison between mean values of the isotope ratios by statistical analysis (ANOVA and Tukey's test) showed that the greatest difference between the 3 types of cheese (local dairy, factory, and imported products) was in the ¹³C/¹²C, ³⁴S/³²S, and ¹⁸O/¹⁶O isotope ratios. In the other parameters, either no differences (δ¹⁵N) or minimal differences (δ²H) were found. Evaluation of the data by multivariate statistical analysis (principal component analysis and hierarchical cluster analysis) revealed that the isotope characteristics of the factory products were similar to those of the cheeses produced from imported raw materials, whereas a difference was found between the local dairy-produced cheeses and the products in the other 2 categories.     

The potential of multielement stable isotope analysis for regional origin assignment of butter

 Regional origin assignment of highly valuable milk products such as butter, is of considerable importance for legal, fiscal and trade controls within the European Union (EU). It is also of value for ensuring fair competition and as a means of protecting consumers against fraud due to mislabelling. Conventional chemical methods of analysis are not able to determine the regional provenance of butter unambiguously. Therefore, stable isotope ratio determinations of the light elements (C,N,O,S; bioelements) and the heavy element, Sr (a trace element), have been used for this purpose. Stable isotope ratios of these elements in natural cycles, their variations due to climate and geology, the abiotic and biological fractionation of isotopes and, finally, the reasons for regional differences in multielement stable isotope ratios of butter are discussed. Results are given for butter from several European countries and from outside the EU. The results indicate that stable isotope ratios and subsequent discriminant analysis based on data for samples of certified origin can enable the reliable detection of the regional provenance of butter. Received: 11 May 1999 / Revised version: 17 August 1999     

植物体中的碳稳定同位素分馏影响因素及在食品真实性鉴别中的研究进展

植物体通过光合作用、呼吸作用等与原产地生态环境进行物质交换,促进自身生长发育和营养物质的合成与积累。碳稳定同位素是植物体的关键组成元素,也是食品真实性鉴别和溯源的重要指标,在植物体整个生育期会随着产地生态环境因子的变化而发生分馏,这种分馏效应的大小决定了碳稳定同位素能否成为准确、稳定、可靠的产地溯源指标。分馏的大小除了生物体自身因素外,还要分析气象因子和生态环境因子对碳稳定同位素的影响,进一步分析影响碳稳定同位素分馏的因素。经纬度、海拔、日照强度、干旱程度、平均气温等因素均会影响碳稳定同位素的组成。本文在大量文献基础上,综述了近年来国内外植物体内的碳同位素分馏及影响因素、植源性食品真实性鉴别应用的研究进展,以期揭示碳稳定同位素可作为产地真实性鉴别指标的稳定性、可靠性特征,从而为产地溯源提供更加准确的技术手段。     

Natural isotope fractionation in the discrimination of sugar origins

More than 500 carbohydrate samples have been characterised by hydrogen, carbon and oxygen isotopic parameters measured on ethanol and water resulting from controlled fermentation. Different chemical states of the carbohydrate pool have been considered: polysaccharides from cereals, tubers and leguminosae (maize, sorghum, rice, wheat, barley, potato, bean), glucose, fructose and sucrose from fruits (pineapple, citrus, apple, soft fruits), sucrose from sugar plants (beet, cane). The overall carbon-13 content of ethanol and the deuterium and oxygen-18 contents of water before fermentation were determined by mass spectrometry of isotope ratios whereas the investigation of site-specific natural isotope fractionation by deuterium NMR has provided access to the deuterium contents in the methyl (I) and methylene (II) sites of ethanol. The results have been analysed in the multidimensional space of these isotopic variables. Hierarchical clustering, principal component and discriminant analyses have been performed. Among fruits, for example, the pineapple group exhibits a 100% discrimination with respect to the apple and citrus groups which are themselves well distinguished. A still higher discrimination is reached between the three groups, citrus, cane and beet, and the addition of 10% exogenous cane or beet sucrose to citrus juice is unambiguously detected.