Carbon and nitrogen natural stable isotopes in Slovene honey: adulteration and botanical and geographical aspects

Isotope parameters (δ(13)C(honey), δ(13)C(protein), δ(15)N) were determined for 271 honey samples of 7 types (black locust, multifloral, lime, chestnut, forest, spruce, and fir honeys) from 4 natural geographical regions of Slovenia. Carbon and nitrogen stable isotope ratios were measured to elucidate the applicability of this method in the identification of the botanical and geographical origin of honey and in honey adulteration. Only 2.2% of the samples were adulterated according to the internal standard carbon isotope ratio analysis method. Botanical origin did not have any major influence on the honey isotope profiles; only black locust honey showed higher δ(13)C values. Some differences were seen across different production years, indicating that the influence of season should be further tested. Statistical and multivariate analyses demonstrated differences among honeys of various geographical origins. Those from the Alpine region had low δ(13)C (-26.0‰) and δ(15)N values (1.1‰); those from the Mediterranean region, high δ(13)C (-24.6‰) and medium δ(15)N values (2.2‰); those from the Pannonian region, medium δ(13)C (-25.6‰) and high δ(15)N value (3.0‰); and those from the Dinaric region, medium δ(13)C (-25.7‰) and low δ(15)N values (1.4‰).     

陕西关中地区肉牛产地同位素溯源技术初探

为应用牛组织中C、N同位素组成的区域分布和同位素指标溯源肉牛产地,本文利用同位素比率质谱仪(IRMS)对陕西关中不同区县来源的牛尾毛样品的1δ3C和1δ5N值进行检测,通过聚类分析,研究陕西关中地区肉牛组织中同位素组成的区域分布情况。结果表明,杨凌区、眉县牛尾毛样品聚为一类;乾县、永寿县样品聚为一类;麟游县样品聚为一类;扶风县、岐山县和凤翔县分类不十分明显,分散在上述3类中。说明陕西关中不同地区肉牛组织中同位素组成存在差异,利用它们可进行肉牛地域的小范围溯源。     

黄土区典型小流域包气带土壤水同位素特征

通过野外调查与室内试验相结合的方法,对王茂沟流域降水及5种土地利用类型土壤剖面稳定氢氧同位素特征进行对比分析,为黄土区土壤水分运移机制、模型参数识别及生态保护与重建提供科学依据。结果表明:(1)降水与5种土地利用方式下土壤水中δD和δ~(18) O的变化范围分别为(-118.08‰)~(-14.37‰),(-16.13‰)~(1.41‰)和(-92.36‰)~(-34.98‰),(-12.48‰)~(-5.01‰),平均值分别为-37.36‰,-5.65‰和-60.18‰,-7.81‰。(2)不同土地利用类型的土壤水氢氧同位素变化存在显著性差异,土壤通透性草地梯田林地坝地坡耕地,表层土壤水分的蒸发分馏程度梯田草地坝地坡耕地林地。(3)林地和草地"优先流"现象明显,草地"优先流"程度最大,林地能显著延伸"优先流"发生路径。(4)草地、林地和梯田分别在160,200,200cm土层及以下氢氧同位素值相对稳定,坝地和坡耕地可能对地下水水质与补给造成较大影响。     

Tracing sources of soil nitrate using the dual isotopic composition of nitrate in 2 M KCl-extracts

Soils comprise a critical interface between the atmosphere, lithosphere, hydrosphere and biosphere, and play a major role in the cycling of nitrogen (N), an element crucial to plant growth. Isotope techniques constitute a powerful tool to study the origin and fate of N compounds (e.g. NO₃⁻) within the environment including soils. The objective of our study was to test the usefulness of the isotope composition of soil NO₃⁻ extracted with 2 M KCl (soil NO₃) as a tool to investigate the origin and fate of NO₃⁻ in the environment. Specifically issues related to repeat extractions, crop type, length of fertilization, and soil depth were addressed. Soils from four contrasting agricultural management regimes were sampled. Within the relatively confined study area (4 ha), the isotopic compositions of soil NO₃ differed markedly due to management treatments (up to 6 and 17‰ for δ¹⁵N and δ¹⁸O, respectively), but were repeatable among replicate plots (±1‰). Differences in both δ¹⁵N and δ¹⁸O values were observed between legume and non-legume treatments, as well as fertilized versus non-fertilized treatments, which were larger than the variability observed between replicate plots. Differences in the isotopic composition of extractable soil nitrate were not limited to the surface layer, but also occurred within deeper soil layers. This study indicates that the analysis of the natural abundance stable isotope composition of soil NO₃ may provide a promising additional tool for tracing the origin and fate of NO₃⁻ in the soil zone.     

稳定性氮同位素技术研究太湖梅梁湾区域营养盐差异

稳定同位素技术通常用于指示外源输入对环境的影响,采用该技术分析了太湖北部不同湖区悬浮颗粒有机物和浮游动物的碳氮稳定同位素比值的差异。结果表明,不同粒径的悬浮颗粒有机物和浮游动物稳定同位素比值存在显著的季节变化,夏季普遍高于冬季,其中δ13C高3.19‰~7.21‰,δ15N高4.20‰~9.36‰。各有机物δ13C不能有效区分各湖区的环境差异,而δ15N在各湖区存在显著差异。δ15N聚类分析显示,河口区由于受外源输入的影响,其δ15N显著低于其他湖区,单独聚为一类,而交汇处和湖心区影响较小,同河口区存在显著差异。整体来讲,总颗粒有机物和浮游动物δ15N同水体TP浓度呈显著正相关,同总溶解性无机氮浓度、铵根离子浓度呈显著负相关。可见,太湖北部悬浮颗粒有机物和浮游动物δ15N受环境营养盐差异的影响强烈,悬浮颗粒有机物δ15N可以作为指示湖区区域差异的有效指标。     

Intramolecular carbon isotope distribution of acetic acid in vinegar

Compound-specific carbon isotope analysis of acetic acid is useful for origin discrimination and quality control of vinegar. Intramolecular carbon isotope distributions, which are each carbon isotope ratios of the methyl and carboxyl carbons in the acetic acid molecule, may be required to obtain more detailed information to discriminate such origin. In this study, improved gas chromatography-pyrolysis-gas chromatography-combustion-isotope ratio mass spectrometry (GC-Py-GC-C-IRMS) combined with headspace solid-phase microextraction (HS-SPME) was used to measure the intramolecular carbon isotope distributions of acetic acid in 14 Japanese vinegars. The results demonstrated that the methyl carbons of acetic acid molecules in vinegars produced from plants were mostly isotopically depleted in (13)C relative to the carboxyl carbon. Moreover, isotopic differences (δ(13)C(carboxyl) - δ(13)C(methyl)) had a wide range from -0.3 to 18.2‰, and these values differed among botanical origins, C3, C4, and CAM plants.     

Multielement isotope analysis of bovine muscle for determination of international geographical origin of meat

Multielemental (C, N, H, S) stable isotope ratio analysis was used as an analytical tool to verify the geographical origin of beef from several European and non-European countries. Beef samples were collected from nine different countries, and the (13)C/(12)C, (15)N/(14)N, (2)H/(1)H, and (34)S/(32)S ratios of defatted beef were measured using isotope ratio mass spectrometry (IRMS). There were highly significant differences in the mean isotopic values of the beef from different countries. The results of discriminant analysis showed that the four isotope ratios were significant for the discrimination of geographical origin and that 84.9% of the samples were correctly assigned to the country of origin (82.2% when cross-validated). Beef was also classified according to geographical origin when additional information on different feeding regimens used in Ireland was included, with 85.0% of the samples correctly allocated and 82.9% cross-validated using the isotopic signatures. All of the Irish beef samples verifiable as pasture-fed beef were correctly classified and then cross-validated.     

不同地域牛尾毛中稳定同位素指纹差异分析

利用同位素比率质谱仪测定来自黑龙江省安达市青肯泡乡和火石山乡、内蒙古太仆寺旗、河北省张家口市和三河市、山东省德州市和聊城市7个地域牛尾毛中的δ13C、δ15N和δ2H值,比较分析了不同地域来源牛尾毛中稳定同位素指纹特征差异,探讨不同地域来源牛尾毛中稳定同位素组成差异、影响因素及地域差异的范围,为牛肉及其产品同位素指纹溯源技术在实际中的应用提供指导。各区域牛尾毛中δ13C值表现为:黑龙江省安达市青肯泡乡(-14.83‰±2.12)、河北省三河市(-14.20‰±1.19)、山东省德州市(-14.16‰±2.51)和山东省聊城市(-15.78‰±1.08)>黑龙江省安达市火石山乡(-18.87‰±1.69)、内蒙古太仆寺旗(-19.29‰±2.43)和河北省张家口市(-19.83‰±1.92);δ15 N值为:黑龙江省安达市火石山乡(8.07‰±0.95)>内蒙古太仆寺旗(5.73‰±0.85)、河北省张家口市(6.65‰±1.45)>黑龙江省安达市青肯泡乡(4.60‰±0.41)、河北省三河市(4.24‰±0.75)、山东省德州市(4.18‰±0.96)和山东省聊城市(4.90‰±0.46);δ2H值为:河北省三河市(-87.78‰±1.99)、山东省德州市(-87.91‰±3.19)和山东省聊城市(-89.24‰±2.90)>河北省张家口市(-94.07‰±3.38)>黑龙江省安达市火石山乡(-97.05‰±3.41)、内蒙古太仆寺旗(-97.55‰±2.79)>黑龙江省安达市青肯泡乡(-102.25‰±2.99)。不同地域来源牛尾毛中稳定碳、氮、氢同位素指纹差异及地域差异范围取决于不同地域喂养牛的饲料组成、地域海拔和纬度的差异程度。     

Comparison of the difference and delta 15Nitrogen approaches for evaluating liquid urea ammonium nitrate utilization by maize

Abstract

Isotopic nitrogen (N) research techniques may be required in watershed studies to determine the impact of landscape position on fertilizer efficiency and the soil supplying power. However, traditional approaches using ^I5N labeled fertilizer may not be suitable when farmer equipment is used. The δ¹⁵N natural abundance isotopic approach has been used to evaluate N cycling in watersheds. The objectives of this study were to measure the precision of the δ¹⁵N measurement by the Europa 20–20 ratio mass spectrometer (Europa Scientific Ltd, UK), and to compare the difference and δ¹⁵N approaches for measuring fertilizer use by maize (Zea mays). A replicated field study containing two different N rates (0 and 15.7 g N m^‐2) were used for the study. Maize samples were collected at the 8th‐leaf, silking, and plant maturity in 1992 and 1993. Samples were dried (80°C), ground (<1‐mm), weighed (stover 12 mg and grain 3 mg), and analyzed fortotal N and δ¹⁵N. Fertilizer utilization at the three growth stages was determined using the natural abundance δ¹⁵N and nonisotopic difference (fertilizer‐control) techniques. During the study, the Europa 20–20 ratio mass spectrometer (Europa Scientific Ltd, UK) analyzed over a 100 samples a day and had consumable costs of less than $2.00 per sample. The standard deviations of the mean were less than 0.11 and 0.21 %o in 51 and 77% of the stover samples, respectively. In 1992, grain yields were not influenced by N fertilizer additions, while in 1993 grain yields were increased by N fertilizer. The difference method estimated that in 1992, 16% of the N fertilizer was utilized by the crop, while the natural abundance δ¹⁵N approach estimated that 36% of the fertilizer N was used by the crop. Differences between calculated values by the two techniques resulted from the difference method calculating net fertilizer use, while the δ¹⁵N approach calculated fertilizer contained in the plant. Because the δ¹⁵N approach estimates fertilizer use, this approach can be used to calculate soil N contained in the plant. In watershed studies, this information may provide the tools needed to evaluate N use in responsive and nonresponsive sites within a field. This research shows that the δ¹⁵N method compliments the difference method, can be used to measure actual fertilizer use when farmer equipment is used, and that the Europa 20–20 ratio mass spectro‐meter (Europa Scientific Ltd, UK) has acceptable precision for the δ¹⁵N natural abundance approach.     

蚕品种对不同发育阶段蚕体、蚕沙及蚕茧稳定同位素特征的影响

丝绸具有重要的经济与文化价值。为探究桑蚕品种对丝绸产地溯源模型准确率的影响,本研究通过桑蚕饲养试验,采用单因素方差分析(one-way ANOVA)和椭圆联合置信区间(EJCR)测试探讨桑蚕从幼虫至吐丝结茧的不同发育阶段蚕体、蚕沙样本中4种稳定同位素比值(δ¹³C、δ¹⁵N、δ²H、δ¹⁸O)的变化趋势,并比较不同品种对稳定同位素比值的影响。结果表明,不同龄期蚕体的δ¹³C、δ¹⁵N、δ²H和δ¹⁸O值变化趋势不同,且不同龄期蚕沙的稳定同位素比值变化趋势与蚕体相似。单因素方差分析结果表明,在相同饲喂条件下,除少数龄期外,不同品种之间蚕体和蚕沙样本稳定同位素组成总体不存在显著差异,且蚕体和蚕沙样本的δ¹³C、δ¹⁵N、δ²H相关性较强。桑蚕品种可能导致蚕茧中单个稳定同位素出现较大变化,对δ¹³C、δ¹⁸O影...     

Chemical profiling with modeling differentiates wild and farm-raised salmon

Classifications of fish production methods, wild or farm-raised salmon, by elemental profiles or C and N stable isotope ratios combined with various modeling approaches were determined. Elemental analysis (As, Ba, Be, Ca, Co, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, and Zn) of wild and farm-raised salmon samples was performed using an inductively coupled plasma atomic emission spectroscopy. Isotopic and compositional analyses of carbon and nitrogen were performed using mass spectrometry as an alternative fingerprinting technique. Each salmon (king salmon, Oncorhynchus tshawytscha ; coho salmon, Oncorhynchus kisutch ; Atlantic salmon, Salmo salar ) was analyzed from two food production practices, wild and farm raised. Principal component analysis (PCA) and canonical discriminant analysis (CDA) were used for data exploration and visualization. Five classification modeling approaches were investigated: linear discriminate function, quadratic discriminant function, neural network, probabilistic neural network, and neural network bagging. Methods for evaluating model reliability included four strategies: resubstitution, cross-validation, and two very different test set scenarios. Generally speaking, the models performed well, with the percentage of samples classified correctly depending on the particular choice of model and evaluation method used.     

有机物对红外光谱技术测定植物叶片和茎秆水δ18O和δD的影响

植物叶片、茎秆和土壤水δ18O和δD是研究土壤植被大气系统生态水文循环过程的重要示踪剂。与传统的稳定同位素质谱(IRMS)技术相比,稳定同位素红外光谱(IRIS)技术具有测量速度快、运行成本低等优势,将促进稳定同位素生态学的发展。但是利用低温真空蒸馏抽提技术获得的植物叶片和茎秆水中含有甲醇和乙醇类有机污染物,造成δ18O和δD的IRIS测量值偏离IRMS测量值(2.64±0.43)‰和(3.6±0.8)‰,超过了仪器精度。本研究利用纯水混入不同浓度的色谱纯甲醇或乙醇,结合Los Gatos公司的光谱分析软件确定甲醇(NB)和乙醇(BB)类物质污染程度的光谱度量值,建立了δ18O和δD的光谱污染校正方法。研究表明,同一台分析仪建立的校正曲线无明显的时间漂移;不同分析仪建立的校正曲线存在显著差异;IRIS校正值与IRMS测量值的交叉验证表明,IRIS测定冬小麦和夏玉米叶片和茎秆水的δ18O和δD可以被准确地校正,与IRMS的差值分别为(0.11±0.12)‰和(0.7±0.4)‰。     

Near-Infrared Reflectance Spectroscopy (NIRS) assessment of δ(18)O and nitrogen and ash contents for improved yield potential and drought adaptation in maize

The oxygen isotope composition (δ(18)O), accumulation of minerals (ash content), and nitrogen (N) content in plant tissues have been recently proposed as useful integrative physiological criteria associated with yield potential and drought resistance in maize. This study tested the ability of near-infrared reflectance spectroscopy (NIRS) to predict δ(18)O and ash and N contents in leaves and mature kernels of maize. The δ(18)O and ash and N contents were determined in leaf and kernel samples from a set of 15 inbreds and 18 hybrids grown in Mexico under full irrigation and two levels of drought stress. Calibration models between NIRS spectra and the measured variables were developed using modified partial least-squares regressions. Global models (which included inbred lines and hybrids) accurately predicted ash and N contents, whereas prediction of δ(18)O showed lower results. Moreover, in hybrids, NIRS clearly reflected genotypic differences in leaf and kernel ash and N contents within each water treatment. It was concluded that NIRS can be used as a rapid, cost-effective, and accurate method for predicting ash and N contents and as a method for screening δ(18)O in maize with promising applications in crop management and maize breeding programs for improved water and nitrogen use efficiency and grain quality.     

Improved characterization of the botanical origin of sugar by carbon-13 SNIF-NMR applied to ethanol

Until now, no analytical method, not even isotopic ones, had been able to differentiate between sugars coming from C4-metabolism plants (cane, maize, etc.) and some crassulacean acid metabolism plants (e.g., pineapple, agave) because in both cases the isotope distributions of the overall carbon-13/carbon-12 and site-specific deuterium/hydrogen isotope ratios are very similar. Following recent advances in the field of quantitative isotopic carbon-13 NMR measurements, a procedure for the analysis of the positional carbon-13/carbon-12 isotope ratios of ethanol derived from the sugars of pineapples and agave using the site-specific natural isotopic fractionation-nuclear magnetic resonance (SNIF-NMR) method is presented. It is shown that reproducible results can be obtained when appropriate analytical conditions are used. When applied to pineapple juice, this new method demonstrates a unique ability to detect cane and maize sugar, which are major potential adulterants, with a detection limit in the order of 15% of the total sugars, which provides an efficient mean of controlling the authenticity of juices made from this specific fruit. When applied to tequila products, this new method demonstrates a unique ability to unambiguously differentiate authentic 100% agave tequila, as well as misto tequila (made from at least 51% agave), from products made from a larger proportion of cane or maize sugar and therefore not complying with the legal definition of tequila.     

Nitrogen isotope composition of organically and conventionally grown crops

Authentic samples of commercially produced organic and conventionally grown tomatoes, lettuces, and carrots were collected and analyzed for their delta15N composition in order to assemble datasets to establish if there are any systematic differences in nitrogen isotope composition due to the method of production. The tomato and lettuce datasets suggest that the different types of fertilizer commonly used in organic and conventional systems result in differences in the nitrogen isotope composition of these crops. A mean delta15N value of 8.1 per thousand was found for the organically grown tomatoes compared with a mean value of -0.1 per thousand for those grown conventionally. The organically grown lettuces had a mean value of 7.6 per thousand compared with a mean value of 2.9 per thousand for the conventionally grown lettuces. The mean value for organic carrots was not significantly different from the mean value for those grown conventionally. Overlap between the delta15N values of the organic and conventional datasets (for both tomatoes and lettuces) means that it is necessary to employ a statistical methodology to try and classify a randomly analyzed "off the shelf" sample as organic/conventional, and such an approach is demonstrated. Overall, the study suggests that nitrogen isotope analysis could be used to provide useful "intelligence" to help detect the substitution of certain organic crop types with their conventional counterparts. However, delta15N analysis of a "test sample" will not provide unequivocal evidence as to whether synthetic fertilizers have been used on the crop but could, for example, in a situation when there is suspicion that mislabeling of conventionally grown crops as "organic" is occurring, be used to provide supporting evidence.     

Compound specific plant amino acid δ15N values differ with functional plant strategies in temperate grassland

The distribution and natural abundance isotopic (δ¹⁵N) content of whole tissue and individual amino acids in plants in a temperate grassland were determined using ion chromatography (IC), continuous flow‐isotope ratio mass spectrometry (CF‐IRMS), and gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS). The results showed that the selected plants (Lolium perenne, Juncus effusus, and Brachythecium rutabulum) differed in their amino acid content and distribution from the parent grassland soil. Bulk and individual amino acid δ¹⁵N isotope signatures were different between the plants, which concurred with their functional strategy in relation to the relative acquisition of available N sources. The individual amino acid δ¹⁵N values of histidine and phenylalanine could be used to differentiate between the three plant species.     

中国三类典型稻田CH4排放的稳定性碳同位素变化

Little is known about the stable carbon isotopes of methane(CH4) emitted(δ~(13)CH_(4emitted)) from permanently flooded rice fields and double rice-cropping fields.The CH4 emission and corresponding δ~(13)CH_(4emitted) under various field managements(mulching,water regime,tillage,and nitrogen(N) fertilization) were simultaneously measured in three typical Chinese rice fields,a permanently flooded rice field in Ziyang City,Sichuan Province,Southwest China,a double-rice cropping field in Yingtan City,Jiangxi Province,Southeast China,and a rice-wheat rotation field in Jurong City,Jiangsu Province,East China,from 2010 to 2012.Results showed different seasonal variations of δ~(13)CH_(4emitted) among the three fields during the rice-growing season.The values of δ~(13)CH_(4emitted) were negatively correlated with corresponding CH4 emissions in seasonal variation and mean,indicating the importance of CH_4 production,oxidation,and transport associated with isotopic fractionation effects to the δ~(13)CH_(4emitted).Seasonal variations of δ~(13)CH_(4emitted) were slightly impacted by mulching cultivation,tillage,and N application,but highly controlled by drainage.Meanwhile,tillage,N application,and especially mulching cultivation had important effects on seasonal mean CH4 emissions and corresponding δ~(13)CH_(4emitted) with low emissions accompanied by high values of δ~(13)CH_(4emitted).Seasonal mean values of δ~(13)CH_(4emitted) from the three fields were similar,mostly ranging from —60‰ to — 50‰,which are well in agreement with previously published data.These demonstrated that seasonal variations of δ~(13)CH_(4emitted) mainly depended on the changes in CH4 emission from rice fields and further indicated the important effects of methanogenic pathways,CH4 oxidation,and CH4 transport associated with isotope fractionation effects influenced by field managements on δ~(13)CH_(4emitted).     

Comparison of a dual‐inlet gas isotope ratio mass spectrometry system and an automated single‐inlet mass spectrometry system for δ13C analysis

Abstract

A dual‐inlet isotope ratio mass spectrometer (VG‐SIRA 12, Isotech, Middlewich, England) using sealed‐glass combustion sample preparation and an automated single‐inlet isotope ratio mass spectrometry system (RoboPrep Sample Converter interfaced with a TracerMass Stable Isotope Detector, Europa Scientific, Crewe, England) were compared for δ¹³C analysis. Two hundred twenty four samples of plant and animal tissue were analyzed for S¹³C using the two systems. Delta ¹³C values obtained from the two instruments were highly correlated (r²=0.986, P=0.0001). The slope of the relationship was not different from one nor was the Y‐intercept different from zero (Y=‐0.2 + 1.0X; P=0.86 and P=0.28 for the slope and Y‐intercept, respectively). In addition, samples from two complete experiments were run on both mass spectrometery systems and statistical analyses performed. In both experiments, differences between treatments were detectable using the RoboPrep system that were not detectable using the SIRA 12 system. In all cases mean δ¹³C values were comparable between the two systems, and coefficients of variation were low; well within acceptable experimental limits.     

油料产品产地溯源技术研究进展

油料产品可为人们提供必需脂肪酸和丰富的脂溶性营养成分,是居民膳食中不可或缺的一部分。然而,油料产品产地造假现象时有发生,损害消费者权益,威胁消费者身体健康,亟需建立有效的油料产品产地溯源技术。本文综述了油料产品产地溯源技术包括矿物元素指纹谱与稳定同位素比率法、光谱法、代谢指纹谱法以及DNA分子标记法等,介绍了几种溯源技术的原理和应用现状,分析了各种方法的优缺点,并对油料产品产地溯源技术应用前景进行展望,以期为油料产品产地溯源技术的进一步发展提供参考。     

花生油生产过程中稳定同位素变化规律及影响因素研究

花生油的稳定同位素特征研究是该技术应用于花生油掺假检测的基础,为探究花生油生产过程中碳、氢、氧的稳定同位素比值变化规律及其受产地、年份的影响,本试验收集了3个年份6个省份的花生样品,利用稳定同位素比值质谱仪(IRMS)测定油脂中3种元素的稳定同位素比值(δ¹³C、δ²H和δ¹⁸O)。结果表明,不同产地花生样品中,油脂的δ¹³C、δ²H和δ¹⁸O值均不相同。以δ¹³C为例,平均值由大到小依次为湖北>辽宁>广东>山东>河南>江苏,部分省份之间差异显著(P<0.05);因年份不同油脂稳定同位素特征也存在差异。另外,研究结果表明不同生产阶段的油脂中稳定同位素特征几乎一致,加工工艺的差异未改变油脂的稳定同位素分馏。可见,油脂中保留了花生的稳定同位素特征。本研究结果为花生油掺假检测技术研究提供了理论基础与应用可行性。