毛细管气相色谱法测定食用油中的酚类抗氧化剂BHA、BHT、TBHQ

建立了同时测定植物油中BHA、BHT、TBHQ等3种酚类抗氧化剂的测定方法。样品中的抗氧化剂经石油醚提取、乙腈萃取后采用HP-5毛细管柱分离。样品加标回收率为82.8?.6%,相对标准偏差为1.06%~3.11%,BHA、BHT、TBHQ的最低检出量分别为5、10、5ng。该方法具有快速、灵敏度高、重现性好、前处理简单等优点。     

固相萃取–气相色谱–串联质谱法测定塑料食品包装材料中3种抗氧化剂的残留量

建立了气相色谱–串联质谱法测定塑料食品包装材料中抗氧化剂二丁基羟基甲苯(BHT)、丁基羟基茴香醚(BHA)和特丁基对苯二酚(TBHQ)残留量的分析方法。样品采用环己烷–乙酸乙酯混合溶剂超声萃取,经固相萃取法富集和净化,采用气相色谱–串联质谱在多反应监测模式下进行测定。结果表明,3种抗氧化剂质量浓度在0.05~20 mg/L范围内线性关系良好,线性相关系数大于0.999;BHT,BHA,TBHQ的检出限分别为0.005,0.01,0.03mg/kg;平均添加回收率为88.7%~104.0%;测定结果的相对标准偏差小于5.5%(n=6)。该方法操作简便,灵敏度高,重复性好,可用于塑料食品包装材料中抗氧化剂BHT,BHA,TBHQ残留量的测定。     

反相高效液相色谱-荧光法同时测定食品中叔丁基对苯二酚和叔丁基羟基茴香醚的含量

1 引言 油溶性抗氧化剂叔丁基对苯二酚(tert-butyl hydroquinone,TBHQ)、叔丁基羟基茴香醚(butylated hydroxyanisole,BHA)和2,6-二叔丁基对甲酚(butylated hydroxytoluene,BHT)是目前最常用的化学合成抗氧化剂,能够有效阻止或延迟油脂氧化变质.     

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。     

植物油中3种抗氧化剂的同时快速分析

建立了向量–子空间夹角判据结合紫外分光光度法测定植物油中3种抗氧化剂的方法,可用于植物油中特丁基对苯二酚(TBHQ)、丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)3种抗氧化剂的同时快速分析。采用紫外光谱–高效液相色谱(UV-HPLC)联用方法对植物油样品进行分离,构建不含待测组分的本底光谱数据库,基于向量-子空间夹角判据算法的步骤分析植物油中3种抗氧化剂的含量。实际样品加标回收率在95.2%~103.3%之间,RSD小于3%(n=6)。对市售15种植物油样品进行分析,其中12种植物油样品检出TBHQ,含量为21.34~30.12μg/m L,15种植物油样品均未检出BHA和BHT。方法适用于植物油中TBHQ,BHA和BHT 3种抗氧化剂的同时快速分析。     

固相萃取-高效液相色谱法测定炒货食品中抗氧化剂

提出了固相萃取-高效液相色谱法测定炒货食品中丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)、叔丁基对苯二酚(TBHQ)和没食子酸丙酯(PG)等人工合成的抗氧化剂和茶多酚、甘草抗氧化物、迷迭香提取物等天然抗氧化剂的方法。样品经甲醇-异丙醇-乙腈(2+1+2)混合溶剂提取后经C_(18)固相萃取柱富集,用甲醇从柱上洗脱抗氧化剂使其净化。洗脱液在50℃氮气吹干,定容至1.0 mL,取10μL试样溶液注入高效液相色谱仪测定。采用反相C_(18)色谱柱为分离柱,以乙腈和三氟乙酸-水(0.05+99.95)溶液为流动相作梯度淋洗,在280 nm作紫外检测(甘草酸在250 nm检测)。各抗氧化剂的质量浓度分别在一定的范围内呈线性关系,方法的测定下限(10S/N)在0.1～1.0 mg·kg~(-1)之间。以油炸花生空白试样为基体,加入标准溶液进行回收试验,测得试样中抗氧化剂的回收率在83.6%～106.0%之间,相对标准偏差(n=6)在1.3%～3.9%之间。     

气相色谱法测定高分子食品包装材料中抗氧化剂的残留量

建立了气相色谱测定高分子食品包装材料中抗氧化剂丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)和特丁基对苯二酚(TBHQ)残留量的分析方法。用环己烷超声萃取高分子食品包装材料样品,考察了萃取时间、温度对抗氧化剂萃取量的影响。萃取液经气相色谱柱HP-50+毛细管柱(30 m×0.53 mm×1 μm)分离,电子捕获检测器(ECD)检测,外标法定量。结果表明: 在抗氧化剂添加量为3.00～10.0 mg/kg范围内,BHT、BHA、TBHQ在高分子食品包装材料中的平均添加回收率分别为88%～93%、92%～101%和83%～97%,相对标准偏差(RSD, n=5)分别为2.01%～2.89%、2.11%～3.19%和2.99%～4.02%;检出限(信噪比为3)分别为0.5、0.5和0.8 mg/kg。对实际高分子食品包装材料样品的检测结果表明3种抗氧化剂在不同材质中均有检出: 塑料材料中抗氧化剂的含量较少,仅有BHT、BHA被检出,含量为6.3～7.8 mg/kg;橡胶材料中3种抗氧化剂均被检出,含量为9.3～28.4 mg/kg。该方法准确、灵敏、重现性好,适用于高分子食品包装材料中抗氧化剂残留量的检测。     

高效液相色谱法同时测定食用油脂和膨化食品中的3种抗氧化剂

建立同时测定食用油脂和膨化食品中3种抗氧化剂丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)、特丁基对苯二酚(TBHQ)的高效液相色谱法.样品经甲醇提取后,以甲醇-0.1%甲酸溶液为流动相梯度洗脱,C18色谱柱分离,采用高效液相色谱法(HPLC)-二极管阵列检测器(DAD),在检测波长280 nm,参比波长360 n...     

高效液相色谱荧光检测法测定食品中的特丁基对苯二酚

1引言特丁基对苯二酚(TBHQ)是一种油溶性抗氧化剂,广泛用于食用油脂,能阻止或延迟油脂氧化变质,目前已在美国等20多个国家使用。因其具有一定的急性毒性和慢性致癌作用,各国对TBHQ的使用都有严格的限量规定,而在日本TBHQ尚未批准作为油脂抗氧化剂,并以此作为一种技术壁垒手段,要求方法检出限值达到1mg/kg。我国对油脂及其制品中抗氧化剂TBHQ的测定有薄层法、比色法、气相色谱法和高效液相色谱法等,但这些方法检出限值均不足以适应油脂制品输日新形势的需要,也有报道采用GC/MS测定TBHQ检出限可在1mg/kg以下,但方法样品前处理复杂,…     

气相色谱-质谱法同时测定食用植物油中三种抗氧化剂

本文研究了用乙醇提取食用植物油中的丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)和叔丁基对苯二酚(TBHQ),并用气相色谱-质谱法对三种抗氧化剂进行分离与测定。方法的线性范围为0.100~20.0 mg/L,检出限为:BHA,3.33μg/L;BHT,3.02μg/L;TBHQ,37.9μg/L。平均回收率为80.6%~123%,相对标准偏差为2.01%~8.77%。该方法具有简便、快速、准确、无毒等特点,应用于大豆油、花生油、芝麻油、菜籽油、茶油、食用调和油中的抗氧化剂的测定,结果令人满意。     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.