食用植物油中矿物油掺假的确证检测方法研究

应用气相色谱 质谱技术,建立了植物油中是否掺加矿物油的确证分析方法。本文报道的方法,简便、快速、准确、灵敏,方法最低检出浓度为1.2g L,经大量样品测定。     

制备液相色谱结合液相色谱-气相色谱联用技术高灵敏检测化妆品中的芳烃矿物油

矿物油是化妆品的重要原料,其主要成分是烷烃矿物油(MOSH),但其中残留的芳烃矿物油(MOAH)会危害人体健康。然而,高比例的MOSH使得化妆品中微量MOAH的分析非常困难,即使采用液相色谱-气相色谱联用技术(LC-GC)也难以准确测定。本研究采用制备液相色谱(Prep-LC)结合LC-GC建立了化妆品中MOAH的高灵敏检测方法。首先采用乙醇和正己烷提取,然后加水实现相分离,得到矿物油提取液;再经过预净化,注入Prep-LC分离。Prep-LC采用纯硅胶柱(250 mm×10 mm, 5μm),洗脱溶剂为正己烷-二氯甲烷二元体系,通过梯度洗脱,可分离去除2 mg以上的MOSH,制备得到高纯度的MOAH组分;经LC-GC和全二维气相色谱-飞行时间质谱(GC×GC-TOFMS)验证,Prep-LC制备的MOAH不含MOSH干扰物。最后,将收集的MOAH浓缩并注入LC-GC进行测定。方法学考察结果表明,本方法的定量限为10 mg/kg,回收率为82.0%～100.8%, RSD为3.6%～7.3%。采用本方法对市售15个口红和唇膏样品进行检测,其中4个样本检出MOAH,含量为204～1460...     

气相色谱-质谱法和主成分投影分析法用于烟用香精的分析和质量控制

采用同时蒸馏萃取法及气相色谱-质谱法对 AB6 香精中挥发性成分进行了提取分离与测定.定性了 15 种成分,占总成分的 80.5%(截除溶剂峰),其中 4 种主要组分在10个不同批次样品中含量的相对标准偏差分别为 3.9%,6.1%,5.7%和 2.2%,由此构成合格样品库,并采用主成分投影分析法有效地区分了掺有溶剂的 AB6 香精与 AB6 香精的合格样品,随着溶剂量的增加它们之间的距离越远,同时,不同品种的香精样品之间也具有显著的差异.气相色谱-质谱法分析和主成分投影分析法可用于香精的质量控制.     

基于高效液相色谱-气相色谱联用技术的矿物油分析研究进展

近年来,利用高效液相色谱-气相色谱联用技术(HPLC-GC)分析矿物油的研究发展迅速。矿物油源于石油与合成油,是涵盖一定碳数范围的碳氢化合物,主要分为烷烃和芳烃两大类。矿物油可通过多种途径迁移至食品和环境中,影响人类健康,然而其分析检测面临较大挑战。HPLC-GC(配备氢火焰离子化检测器)通过将净化、分离与检测相结合,很好地解决了矿物油分析中的选择性和灵敏度等问题。该技术的核心是通过保留间隙、Y形件接口和溶剂蒸气排出实现了GC大体积进样,将常规HPLC的洗脱流分全部转移至GC分析,将矿物油的分析灵敏度提高了两个数量级以上;同时避免了分析过程的污染引入,保证了分析的重现性和准确度。本文详细阐述了HPLC-GC的发展历程以及HPLC与GC分析条件的相互匹配,评述了基于HPLC-GC联用技术的干扰物去除与矿物油富集方法,并对HPLC-GC在矿物油分析中应用前景和发展趋势进行了展望。     

液相色谱-毛细管气相色谱/质谱离线联用分析烟草中的挥发性及半挥发性成分

建立了一种用于烟草样品中挥发性、半挥发性成分分析的液相色谱-毛细管气相色谱/质谱(LC-CGC/MS)离线联用方法。研究了LC-CGC/MS的分离机理。LC分析选用氨基分析柱(250 mm×2.0 mm, 5 μm)作为分析柱,正己烷-二氯甲烷-乙腈(90:6.6:3.4, v/v/v)作为流动相,对挥发性、半挥发性成分进行分离,收集得到5个馏分,并存放在5个氮吹瓶中。多次进样并收集相同时间段的馏分,氮吹浓缩至1 mL,然后分别进行CGC/MS分析,所用的CGC柱为DB-5MS(60 m×0.25 mm×0.25 μm)。结果显示,与直接采用CGC/MS分析相比,采用LC-CGC/MS分析复杂样本的效果更好,定性的可靠性更高。     

柠檬草的SFE-GC/MS谱图及其主成分分析

收集了4个产地的12个柠檬草样品,用超临界萃取-气相色谱/质谱法(SFE-GC/MS)在L_9(3~4)正交试验表优化萃取条件下(温度35℃、压力20MPa、静态萃取时间40min和动态萃取时间40min)测得柠檬草萃取物的色谱图,经质谱分析对比NIST 08谱库并结合相关文献对萃取物化学成分做了鉴定。对柠檬草化学成分按照醛类、酯类、醇类、烯类、其他进行归类计算峰面积百分含量,结合主成分分析(PCA)建立判别模型,对4个产地的12个柠檬草样品进行产地溯源研究。本研究结果表明,利用SFE-GC/MS结合PCA能对柠檬草进行有效的产地溯源,实用性良好。     

不同种兰花香气成分分析

利用固相微萃取和气相色谱-质谱联用(GC-MS)技术分析了5种兰花的香气成分。结果表明,5种兰花香气成分的种类和含量存在明显差异。绿苹果(Den.LittleGreen Apples)主要由反-2-己烯醛、己醛、丁羟甲苯、乙酸乙酯和3-己烯-1-醇等化合物构成,其中乙酸乙酯和反-2-己烯醛可能是花朵中苹果香的主要来源。香水文心兰(Onc.Sharry Baby)的主要香气化合物是顺-3,7-二甲基-1,3,6-辛三烯、3,7-二甲基-2,6-辛二烯-1-醇和3,7-二甲基-1,6-辛二烯-3-醇,三者的相对含量总和为84.57%。台北小姐(Cym.Miss Taipei)香气成分的主要特征不明显,除4-甲基苯酚和2-乙基丁醛外,其他化合物的相对含量均低于5%。夕阳红(Phal.Taida Salu)有香气成分50种,相对含量为87.01%,主要成分为柯巴烯、正己烷、甲酸己酯和3-己烯-1-醇。绿世界(Blc.Sung Ya Green‘green world’)有香气成分37种,主要由丙基环丙烷、2-(4-甲氧基苯基)乙醇、反-2-己烯-1-醇、3-己烯-1-醇、反-2-己烯醛、丁基呋喃和3,7,11-三甲基-1,6,10-十二碳三烯-3-醇等组成。     

气相色谱-质谱法测定蜂蜡净油中限用成分

提出了气相色谱-质谱法测定蜂蜡净油中限用成分含量的方法。样品经二氯甲烷-三氯甲烷(1+1)混合溶剂溶解,采用不同极性的两根色谱柱分离后,选择离子监测模式下质谱法进行测定。共鉴定出96种化合物,其中香豆素和马索亚内酯是禁用成分。苯甲醇、肉桂醇、香豆素、马索亚内酯、苯甲酸苄酯、水杨酸苄酯和肉桂酸苄酯等7种限用物质的质量浓度在0.08～80mg.L-1范围内呈线性关系,检出限(3S/N)在0.01～0.23mg.kg-1之间。样品加标回收率在86%～101%之间,相对标准偏差(n=6)小于4.0%。     

静态顶空-气相色谱-质谱法分析不同产地大红袍花椒中挥发性成分

3个省份9个产地的大红袍花椒样品经筛选、自然晾干后过孔径为0.425 mm筛网。分取1.0 g置于20 mL顶空瓶中,用卷边器封口,在加热箱温度100℃、定量环温度110℃条件下平衡30 min。所得挥发性成分进入气相色谱仪,在DB-17MS毛细管色谱柱上进行程序升温分离,并用附电子轰击离子源的质谱仪检测,以保留时间和定性离子定性,以峰面积归一法半定量,以主成分分析法寻找区分不同产地的差异性物质。结果显示：在9个产地样品中共检出120种挥发性成分,烯烃、芳香烃、烷烃、醇、醛、酚、酮、酯类化合物分别有56,2,10,24,7,1,12,8种;共有成分12种,其中柠檬烯相对含量较高(9.646%～48.985%);2-甲基-5-(1-甲基乙烯基)-2-环己烯-1-醇和乙酸松油酯可作为区分不同产地样品的差异性物质,对甲-α-甲基苯乙烯、石竹烯可作为辅助差异性物质。     

大蒜素的检测及大蒜辣素分解机理的探讨

通过正交试验方法,研究了硫酸钡吸光比浊法测定大蒜中大蒜素含量的最佳实验条件。在选定实验条件下,体系的吸光度与硫酸根离子浓度呈线性关系,相关系数r为0.9985,相对标准偏差(RSD)为0.86%。采用高效液相色谱法对样品中二烯丙基二硫醚进行定量检测,其检测结果与吸光比浊法的结果具有一定的互补对照性。在此基础上采用红外光谱法、气相色谱-质谱法对大蒜素中含硫活性成分进行定性分析,并将四种方法结果进行对比,对大蒜辣素过热分解的机理进行了探讨,为大蒜素中不同含硫化合物之间的转化提供了依据。     

On-line LC-GC-AED and LC-GC-MS – multidimensional methods for the analysis of PAC in fuels,combustion emissions and atmospheric samples

The composition and concentration of polycyclic aromatic compounds (PAC) in fuels. Theier combustion products and in the atmosphere remains a topic of considerable interest. Despite the wealth of literature on the identification of PAC, speciation at low concentrations remains difficult due to instrument limitation and the complexity of fuel and environmental samples. Consequently on line sample preparation procedures (SPE, SFE, LC, etc.) are becomeing an increasingly important step in the analysis procedure particularly where sample clean-up and fractionation are essential for improving analytical resolution. In this study a normal phase high pressure analytical resolution. In this study a normal phase high pressure liquid chromatography-gas chromatography (LC-GC) system has been developed to provide quantitative analysis of samples, as diverse as coal liquids, petroleum fuels, diesel exhaust particulates, and urban air particulates. Separation and identification of parent and alkylated PAH, hetercycline nitro-and oxy-PAC can be achieved by direct coupling to an atomic emission detector and a bech top mass spectrometer. For both systems the primary LC separation combined with the large sample volume transferred to GC vastly improves detection limits. Furthermore the complimentary nature of the two detectors used enables the positive indentification of many unknowns.     

Determination of Bitterness of Extra Virgin Olive Oils by Amperometric Detection

A flow injection system with amperometric detection at potentials poised at +0.4 and +0.9 V was used to evaluate intensity of the bitter taste in monovarietal Extra Virgin Olive Oils (EVOO). Results from the proposed method were based on the extraction of the bitter constituents of the virgin olive oil samples in methanol‐water, followed by the direct amperometric measurement. These potentials were selected according to the hydrodynamic voltammogram of oleuropein, one of the most prominent and bitter phenolic compound found in EVOO. The amperometric detection was applied on 32 monovariatal EVOO samples. Results were correlated with the phenolic profile measured by high performance liquid chromatography (HPLC). The amperometric signal at +0.9 V mainly correlated with the total phenols of the samples (R²=0.81), whereas the signal at +0.4 V mainly correlated with oleuropein aglycone (3,4 DHPEA‐EDA, R²=0.79). Bitterness intensity of the samples was evaluated by a trained sensory panel of experts and the results compared to those obtained by the amperometric flow system. The best correlation with the bitter taste was achieved by the sensor at +0.4 V (R²=0.72). A calibration model based on partial least squares was built with three variables, namely the sensors set at +0.4 and +0.9 V and the total phenol content of the EVOO extracts. The model showed a moderate capacity to predict the bitterness of the EVOO samples using leave one out method, (R²=0.75) and in prediction of a test set of samples (R²=0.7). Such approach is very promising for future studies.     

LF-NMR结合化学模式识别鉴别油脂种类及餐饮废弃油脂

应用主成分分析(Principal component analysis,PCA)和聚类分析法(Cluster analysis,CA)对9种(27个)常见食用植物油及100个餐饮废油的低场核磁共振(Low-field nuclear magnetic resonance,LF-NMR)(T2)弛豫特性数据进行分析。结果表明:在正常食用油种类区分方面,主成分分析的效果较优,9种食用油在主成分分布图上按种类正确分组,边界清晰。而在正常食用油与餐饮废油的区分方面,聚类分析效果较优,引入30个待测样本后,聚类分析(127个样品,欧式距离=5)的正确率为94.49%,分析误判率为5.51%,分组效果良好。LF-NMR结合化学模式识别可实现对油脂种类及餐饮废弃油脂的鉴别。     

气相色谱-质谱技术结合化学计量学对5种动物油进行判别分析

测定了5种不同种类动物油(鸡油、牛油、鸭油、羊油和猪油)的脂肪酸组成和含量,探讨了利用动物油脂肪酸的指标对不同种类的动物油进行分类和判别的可能性。采用气相色谱-质谱联用技术(GC-MS)对5种动物油脂肪酸的组成和含量进行测定,利用SPSS 19.0统计软件进行主成分分析、聚类分析和判别分析。对5种动物油的脂肪酸进行统计、分析和对比,得出动物油的主要组成为C16∶0,C18∶0,C18∶1c-9,C18∶2c-9,12和C14∶0,这5种脂肪酸在鸡油、牛油、鸭油、羊油和猪油中的总含量分别为92.1%,93.5%,93.5%,90.6%和95.6%。5种脂肪酸的不饱和度均小于1。主成分分析降维得到3个主成分,利用主成分分析数据,依次进行聚类分析和判别分析,建立了3个动物油典则判别函数,相关系数均大于0.995,对于鸡油、牛油、鸭油、羊油和猪油的初始分类正确率和交叉验证正确率均为100%。     

硅烷化GC-MS指纹图谱在卷烟品牌分析中的应用

采用硅烷化衍生化法结合气相色谱-质谱(GC-MS)法对卷烟烟丝中的主要化学成分进行检测,获得了21个卷烟样品的烟丝硅烷化GC-MS指纹图谱数据,并应用聚类分析和主成分分析法对烟丝硅烷化GC-MS指纹图谱数据进行综合评价。结果表明,该方法可用于不同品牌卷烟的比较和区分,硅烷化成分的含量分布特征能反映不同品牌卷烟的特性,可为卷烟品牌的风格表征、品质维护和真伪鉴别提供参考。     

食品接触用再生塑料的非有意添加物和鉴别技术研究进展

随着塑料废弃物导致的环境污染加重,塑料的回收利用备受关注。食品接触用再生塑料逐渐成为关注的重点,再生塑料中非有意添加物的安全性是将其用作食品接触材料的关键所在。为了避免不合规的再生塑料流入食品接触材料市场,危害消费者的健康安全,再生塑料的鉴别技术显得非常重要。该文首先对再生塑料中非有意添加物的研究进行总结,并重点概述了国内外对原生和再生塑料的鉴别技术,如质谱技术、光谱技术和热分析技术;近年来化学计量学方法也逐渐被用于再生塑料鉴别领域,提高了再生塑料的鉴别效率和准确率。     

超高效液相色谱-质谱法测定油脂中的10种抗氧化剂

对油脂中的没食子酸丙酯(PG),没食子酸辛酯(OG)、2,4,5-三羟基苯丁酮(THBP)、叔丁基对苯二酚(TBHQ)、叔丁基对羟基茴香醚(BHA)、2,6-二叔丁基对甲酚(BHT)、没食子酸十二酯(DG)、正二氢愈创酸(NDGA)、2,6-二叔丁基-4-羟甲基苯酚(HMBP)和没食子酸异戊酯(IAG)10种抗氧化剂进行了超高效液相色谱-质谱法(UPLC/MS)测定的系统研究,建立了一种简单、快速、准确测定油脂中10种抗氧化剂的测定方法。对样品中提取溶剂和提取时间的选择以及相关线性、精密度、回收率作了考察和实验。结果表明,本方法能有效提取油脂样品中的这10种抗氧化剂,并对其进行UPLC/MS分离和测定。10种抗氧化剂的平均回收率为92.56%～102.5%(n=6),相对标准偏差为0.68%～5.12%(n=6),检出限为2～10μg/L。     

Utilizing AgNPt-SALDI to Classify Edible Oils by Multivariate Statistics of Triacylglycerol Profile

Edible oils are valuable sources of nutrients, and their classification is necessary to ensure high quality, which is essential to food safety. This study reports the establishment of a rapid and straightforward SALDI-TOF MS platform used to detect triacylglycerol (TAG) in various edible oils. Silver nanoplates (AgNPts) were used to optimize the SALDI samples for high sensitivity and reproducibility of TAG signals. TAG fingerprints were combined with multivariate statistics to identify the critical features of edible oil discrimination. Eleven various edible oils were discriminated using principal component analysis (PCA). The results suggested the creation of a robust platform that can examine food adulteration and food fraud, potentially ensuring high-quality foods and agricultural products.     

Toward the Non-Targeted Detection of Adulterated Virgin Olive Oil with Edible Oils via FTIR Spectroscopy & Chemometrics: Research Methodology Trends,Gaps and Future Perspectives

Fourier-Transform mid-infrared (FTIR) spectroscopy offers a strong candidate screening tool for rapid, non-destructive and early detection of unauthorized virgin olive oil blends with other edible oils. Potential applications to the official anti-fraud control are supported by dozens of research articles with a “proof-of-concept” study approach through different chemometric workflows for comprehensive spectral analysis. It may also assist non-targeted authenticity testing, an emerging goal for modern food fraud inspection systems. Hence, FTIR-based methods need to be standardized and validated to be accepted by the olive industry and official regulators. Thus far, several literature reviews evaluated the competence of FTIR standalone or compared with other vibrational techniques only in view of the chemometric methodology, regardless of the inherent characteristics of the product spectra or the application scope. Regarding authenticity testing, every step of the methodology workflow, and not only the post-acquisition steps, need thorough validation. In this context, the present review investigates the progress in the research methodology on FTIR-based detection of virgin olive oil adulteration over a period of more than 25 years with the aim to capture the trends, identify gaps or misuses in the existing literature and highlight intriguing topics for future studies. An extensive search in Scopus, Web of Science and Google Scholar, combined with bibliometric analysis, helped to extract qualitative and quantitative information from publication sources. Our findings verified that intercomparison of literature results is often impossible; sampling design, FTIR spectral acquisition and performance evaluation are critical methodological issues that need more specific guidance and criteria for application to product authenticity testing.     

气相色谱-质谱联用法结合保留指数对高良姜挥发油成分的分析

采用气相色谱-质谱联用(GC-MS)法结合保留指数(RI)对高良姜水蒸气蒸馏法(SD)、超声波辅助溶剂提取法(UAE)和亚临界流体萃取法(SFE)所制备的挥发油进行分析,分别鉴定出51,46和60个挥发性组分,并通过峰面积归一化法确定各组分的相对含量。结果表明,高良姜挥发油的指标性成分1,8-桉叶素含量的大小顺序为SD法≈SFE法UAE法,UAE法虽耗时少、能耗低,但由于所用有机溶剂难去除,所得挥发油品质较差。SFE法可得到部分SD法无法得到的化合物,如2-羟基-1,8-桉叶素、二苯基庚烷类等。另外β-石竹烯、α-石竹烯、α-法尼烯、γ-杜松烯等高沸点组分比例,SFE法所得高于另两种方法;α-蒎烯、莰烯、β-蒎烯、柠檬烯、樟脑和α-松油醇等低沸点组分比例,SD法所得最高。同一批药材不同提取方法所得的挥发油成分大部分相似,但部分成分与组分比例因不同提取方法的原理存在差异,实际生产中可根据功效需求选择不同提取方法加以开发利用。