基于微波消解的ICP-OES/ICP-MS法测定茶叶中30种矿物质元素

本文建立微波消解电感耦合等离子体光谱法/电感耦合等离子体质谱法（ICP-OES/ICP-MS）测定茶叶中矿物质元素的含量,分析和探究某地区茶叶中矿物质元素的组成。ICP-OES测定营养元素,在质量浓度0²00 mg/L范围内线性相关系数处于0.9995¹.0000之间,检出限全部不高于0.05 mg/L;ICP-MS测定重金属元素和稀土元素氧化物总量,在质量浓度0¹00μg/L范围内线性相关系数处于0.9996¹.0000之间,检出限均不高于0.082μg/L。监测了福建地区32个茶叶样品的矿物质元素分布,该方法快速简便、灵敏度高,适合通量测定茶叶样品的元素组成,为科学地评价茶叶中矿物质含量提供数据参考。      

微波消解结合ICP-OES和ICP-MS测定奇亚籽中多种矿物质元素的含量

建立奇亚籽中K (钾)、Na (钠)、Ca (钙)、Mg (镁)、Fe (铁)、Mn (锰)、Zn (锌)、Cu (铜)、P (磷)、B (硼)、Pb (铅)、Cd (镉)、As (砷)、Cr (铬)、Al (铝)、Ni (镍)16种矿物质元素的方法。样品经微波消解,以电感耦合等离子发射光谱(ICP-OES)测定K、Na、Ca、Mg、Fe、Mn、Zn、Cu、P、B含量,电感耦合等离子质谱(ICP-MS)测定Pb、Cd、As、Cr、Al、Ni含量。结果表明,此方法的ICP-OES检出限范围在0.00850~0.10200 mg/L,定量限范围在0.0283~0.3400 mg/L;ICP-MS检出限范围在0.00471~0.11330 mg/L,定量限范围在0.0157~0.3777 mg/L。线性相关系数均为r＞0.999,加标回收率为90.4%~99.8%,相对标准偏差为0~4.1%。同时用国家标准物质大米(GBW10045(GSB-1))和小麦(GBW10011(GSB-2))评价了方法的准确性,测定结果在标准值范围内。奇亚籽中含有丰富的P、K、Ca、Mg,其中P含量最高,为6860 μg/g,Ca含量为4085 μg/g,K含量为2798 μg/g,Mg含量为2515 μg/g;Fe、Zn、Al、Mn、Cu、Na、B含量(由高到低)在5~100 μg/g。同时检测出重金属危害元素Pb、Cd、Cr、Ni,其中Pb含量符合食品安全国家标准GB 2762-2017的限量要求,未能检测出As。该方法污染小、简便、高效、准确度高,适用于奇亚籽等植物类样品中多种化学元素的测定。     

Volatile fraction of commercial thyme honeys produced in Mediterranean regions and key volatile compounds for geographical discrimination: A chemometric approach

The aim of the present study was to investigate the volatile fraction and discriminate 34 commercial thyme honeys from Morocco, Egypt, Spain, and Greece according to geographical origin, using key volatile compounds in combination with chemometrics. Sixty-two volatile compounds belonging to different classes were identified and semi-quantified using headspace solid phase micro-extraction coupled to gas chromatography/mass spectrometry (HS-SPME-GC/MS). Applying chemometric analyses to 17 volatiles (p < 0.05), honeys were successfully discriminated according to geographical origin. Correct classification rate was 88.2% using the cross-validation method. Volatile compounds proved to be a powerful tool for discriminating commercial thyme honeys from different countries.     

羊肉的产地溯源和鉴别技术研究进展

随着羊肉消费量不断增加和相关食品安全问题频现,对羊肉溯源和掺假鉴别技术的需求已经成为当前社会的关注热点之一。目前,对于羊肉的溯源和鉴别已有相应研究,稳定同位素技术、矿物质元素指纹图谱、近红外光谱、DNA分子标记溯源技术、基于脂肪酸的溯源和鉴别技术、基于风味化合物的产地溯源和鉴别技术等在溯源和鉴别研究中得到了大量应用。但在这些技术不断发展的同时,也暴露出了一些亟待解决的问题。本文基于当前羊肉溯源和鉴别技术的相关研究资料和文献,对相应技术的优缺点进行总结和讨论,分析目前技术研究中存在的问题,并提出相应的建议和解决方法,以期为羊肉溯源和鉴别的进一步研究提供理论支持。     

Determination of the geographical origin of wine using joint analysis of elemental and isotopic composition. II—Differentiation of the principal production zones in france for the 1990 vintage

Stable isotope analysis of grape juices and fermented products involving 2H-NMR spectroscopy and isotope ratio mass spectroscopy was carried out in combination with elemental determinations performed by atomic absorption spectroscopy using flame and thermal ionisation. One hundred and sixty five grape samples were carefully collected in well-defined vineyards of France situated in Alsace, Burgundy, Beaujolais and the Loire Valley. Moreover, the samples from Burgundy were picked from four typical Appellations (Cǒtes de Nuits, Cǒtes de Beaune, Cǒtes Chalonnaises and Mǎconnais) in order to ‘zoom’ the approach to smaller production areas. An exhaustive statistical evaluation of the 165 ± 16 data set was carried out by analysis of variance and principal component analysis. To conclude this study, the classification of the samples in typical Appellations was carried out by discriminant analysis with a nearly 100% degree of achievement.