罐装饮料中双酚A-二缩水甘油醚与双酚F-二缩水甘油醚及其衍生物的快速检测

建立了固相萃取/超高效液相色谱法测定罐装饮料中9种双酚-二缩水甘油醚,包括双酚A-二缩水甘油醚(BADGE)及其衍生物BADGE·2H2O、BADGE·H2O、BADGE·2HCl、BADGE·HCl、BADGE·H2O·HCl和双酚F-二缩水甘油醚(BFDGE)及其衍生物BFDGE·2H2O、BFDGE·H2O的快速检测方法。采用叔丁基甲醚为提取溶剂,涡旋振荡提取,提取液氮吹至近干后用甲醇-水(2∶3)溶解,采用PLS亲水亲酯柱固相萃取净化。以Shim-pack XR-ODS-Ⅲ为分析柱,乙腈-水为流动相进行梯度洗脱。9种双酚-二缩水甘油醚在0.05~10 mg/L范围内线性关系良好,回收率为83.8%~98.7%,RSD为2.3%~5.6%,方法检出限为20μg/kg。该方法操作简单、灵敏度高,可在10 min内对罐装饮料中9种双酚-二缩水甘油醚进行快速检测。     

食品罐内壁涂料中双酚-二缩水甘油醚的快速检测和迁移规律

建立了快速、简便的超高效液相色谱法同时测定食品模拟物中双酚A-二缩水甘油醚(BADGE)、双酚F-二缩水甘油醚(BFDGE)及其衍生物特定迁移量的方法。采用水、3%乙酸、10%乙醇和葵花籽油4种食品模拟物在60℃、10 d的条件下模拟了食品罐内壁涂料中双酚-二缩水甘油醚的迁移。水性食品模拟物直接进样,葵花籽油模拟物采用乙腈提取,提取液经固相萃取净化后进样。迁移到水性食品模拟物中的BADGE、双酚A-(3-氯-2-羟丙基)甘油醚(BADGE·HCl)发生水解,分别转化成双酚A-二(2,3-二羟丙基)醚(BADGE·2H2O)和双酚A-(3-氯-2-羟丙基)(2,3-二羟丙基)醚(BADGE·H2O·HCl);迁移到油性模拟物中的BADGE和BADGE·HCl则没有发生水解。9种双酚-二缩水甘油醚在0.05~10 mg/L范围内线性关系良好,水性食品模拟物和油性食品模拟物中方法的检出限分别为5μg/L和20μg/kg。应用本方法对10种未接触过食品的空罐进行了检测,有5种样品中检出了BADGE及其衍生物,其中1种样品中BADGE·2H2O(或BADGE)和BADGE·H2O·HCl(或BADGE·HCl)在4种食品模拟物中的迁移量均超过了欧盟EC/1895/2005规定的限量。     

高效液相色谱-串联质谱法同时测定肉类罐头中双酚-二缩水甘油醚

建立了同时测定肉类罐头中双酚A-二缩水甘油醚(BADGE)、双酚F-二缩水甘油醚(BFDGE)及其衍生物双酚A-(2,3-二羟丙基)甘油醚(BADGE•H2O)、双酚A-双(2,3-二羟丙基)醚(BADGE•2H2O)、双酚A-(3-氯-2-羟丙基)(2,3-二羟丙基)醚(BADGE•H2O•HCl)、双酚A-(3-氯-2-羟丙基)甘油醚(BADGE•HCl)、双酚A-双(3-氯-2-羟丙基)醚(BADGE•2HCl)、双酚F-双(2,3-二羟丙基)醚(BFDGE•2H2O)、双酚F-双(3-氯-2-羟丙基)醚(BFDGE•2HCl)9种环境激素的高效液相色谱-串联质谱分析方法。样品经叔丁基甲醚提取,HLB固相萃取小柱净化,C18色谱柱分离,用5 mmol/L醋酸铵溶液(含0.1%甲酸)与甲醇为流动相梯度洗脱,质谱多反应监测(MRM)模式检测,基质标准校正,外标法定量。结果表明,这9种化合物在10.0～2000.0 μg/L范围内线性关系良好;定量限(以信噪比≥10计)为10.0 μg/kg;在高、中、低3个加标水平下9种化合物的平均添加回收率为79.6%～100.9%,相对标准偏差为6.3%～12.1%。该方法具有较高的灵敏度和准确度,能满足法规要求的对肉类罐头中双酚A-二缩水甘油醚、双酚F-二缩水甘油醚及其衍生物残留量的快速检测及准确定量。     

多壁碳纳米管固相萃取-高效液相色谱-串联质谱法测定食品接触材料中双酚-二环氧甘油醚的迁移量

建立了测定食品接触材料中6种双酚-二环氧甘油醚(双酚A二缩水甘油醚(BADGE)及其衍生物双酚A(2,3-二羟丙基)甘油醚(BADGE•H2O)、双酚A(3-氯-2-羟丙基)甘油醚(BADGE•HCl)、双酚A(3-氯-2-羟丙基)(2,3-二羟丙基)醚(BADGE•H2O•HCl)和双酚F二缩水甘油醚(BFDGE)及其衍生物双酚F双(3-氯-2-羟丙基)甘油醚(BFDGE•2HCl))迁移到食品中的迁移量的高效液相色谱-串联质谱法(HPLC-MS/MS)。样品以叔丁基甲醚(MTBE)为提取溶剂,超声提取,提取液经多壁碳纳米管(MWCNTs)固相萃取(SPE)柱富集、净化。以COSMOSIL C18为分析柱,流动相为0.1%甲酸的5 mmol/L醋酸铵溶液和甲醇。6种双酚-二环氧甘油醚在1.0～100 μg/L范围内线性关系良好(r2＞0.9991)。在3个添加水平下,6种目标化合物的回收率范围为78.6%～89.9%,相对标准偏差小于10%。方法检出限范围为0.5～1.5 μg/L。该方法操作简单,灵敏度高,可应用于食品接触材料中双酚-二环氧甘油醚迁移量的快速检测。     

固相萃取-高效液相色谱-串联质谱测定水中8种双酚-二环氧甘油醚

建立了水中8种双酚-二环氧甘油醚（双酚A二缩水甘油醚（BADGE）及其衍生物双酚A（3-氯-2-羟丙基）甘油醚（BADGE·5HCl）、双酚A双（3-氯-2-羟丙基）醚（BADGE·52HCl）、双酚A（2,3-二羟丙基）甘油醚（BADGE·5H₂O）、双酚A双（2,3-二羟丙基）醚（BADGE·52H₂O）、双酚A（3-氯-2-羟丙基）（2,3-二羟丙基）醚（BADGE·5HCl·5H₂O）和双酚F-二环氧甘油醚（BFDGE）及其衍生物双酚F双（3-氯-2-羟丙基）醚（BFDGE·52HCl））的固相萃取-高效液相色谱-串联质谱（SPE-HPLC-MS/MS）测定方法。10个饮用水接触涂料样品在室温避光条件下,以超纯水浸泡（24±1）h,然后取200 mL经C₁₈固相萃取柱进行净化浓缩,以C₁₈色谱柱进行分离,以5 mmol/L醋酸铵、甲醇和水为流动相进行梯度洗脱,质谱多反应监测（MRM）模式检测,外标法定量。结果表明,8种双酚-二环氧甘油醚在0.007~5.00 μg/L线性关系良好,相关系数均大于0.9990,该方法对8种双酚-二环氧甘油醚的定量限为7~91 ng/L,回收率为79.1%~101%,RSD为4.0%~12%。该方法具有灵敏度高、选择性强的特点,能够满足水中双酚-二环氧甘油醚的快速检测和准确定量。     

食品包装污染物双酚类化合物的固相萃取技术研究

建立并优化了水样中双酚类化合物的固相萃取(SPE)方法。选择C18反相萃取小柱,以3mL 20%甲醇为淋洗液,6mL甲醇为洗脱液,使用高效液相色谱-荧光检测器进行定量测定。该方法对双酚A(BPA)、双酚B(BPB)、双酚E(BPE)、双酚F(BPF)、双酚A二缩水甘油醚(BADGE)和双酚F二缩水甘油醚(BFDGE)6种双酚类化合物的回收率在95.43%~102.10%之间,相对偏差均低于5%,准确度和精密度良好。另外选取四种类型食品模拟物来验证SPE富集双酚类化合物的效果,结果表明6种双酚类化合物在模拟物中的回收率为75.92%~102.10%,相对标准偏差为1.11%~4.99%,准确度与精密度均良好。     

高效液相色谱法测定金属涂层罐中9种双酚类环氧衍生物的迁移量

为了评估金属涂层罐中双酚类环氧衍生物的迁移风险,建立高效液相色谱法测定金属涂层罐中9种双酚类环氧衍生物的迁移量。选择水、3%乙酸、10%乙醇、玉米油为食品模拟物;迁移条件:于121℃处理30min后,再于60℃保温10 d;流动相为水–乙腈,梯度洗脱;FLD检测器的激发波长为235 nm,发射波长为312 nm。双酚A-二缩水甘油醚(BADGE)及其衍生物分别在30～10 000μg/L(水、3%乙酸、10%乙醇),30～2 000μg/L (玉米油)范围内与色谱峰面积呈良好的线性关系;双酚F-二缩水甘油醚(BFDGE)及其衍生物分别在100～10 000(水、3%乙酸、10%乙醇),100～2 000(玉米油)范围内与色谱峰面积呈良好的线性关系,相关系数均不低于0.995 0,检出限为0.03mg/L(BADGE及其衍生物)和0.1mg/L(BFDGE及其衍生物),测定结果的相对标准偏差不大于7.39%(n=6),加标回收率为80.32%～113.86%。该方法可用于金属涂层罐中9种双酚类环氧衍生物迁移量的快速检测。     

加速溶剂萃取-液相色谱-质谱/质谱法分析动物组织中的壬基酚、辛基酚和双酚A

建立了测定内分泌干扰物质烷基酚、双酚A的液相色谱-电喷雾串联质谱(负离子模式)分析方法,优化了样品前处理方法。以二氯甲烷作提取溶剂,采用加速溶剂萃取法萃取动物组织样品,萃取液用500 mg OASIS氨基固相萃取柱进行浓缩净化。对流动相组分和流动相添加剂对质谱的离子化效率进行了考察,测得3种化合物在高、中、低3个添加水平的回收率为88%~101%,相对标准偏差小于15%;双酚A、壬基酚和辛基酚的方法检出限分别为0.3, 0.05和0.1 μg/kg。对从北京市场上采集的27份动物组织样品进行检测,结果表明壬基酚广泛存在于各种动物源性食品中,检出含量为0.49~55.98 μg/kg,其中鱼肉组织中都检出壬基酚,而且其含量也较高(9.13~55.98 μg/kg)。     

衍生化固相微萃取与气相色谱-质谱联用测定生活垃圾渗沥液中双酚A

建立了固相微萃取-顶空衍生化与色谱-质谱联用技术测定水中双酚A定量分析方法。对影响萃取和衍生化过程的参数进行了条件优化,实验选用聚丙烯酸酯(PA)萃取纤维,在搅拌速度为1200r/min、溶液离子强度100g/L、pH2和25℃的条件下萃取60min后,N,O双(三甲基硅烷基)三氟乙酰胺(BSTFA)顶空衍生化5min。方法的线性范围是0.09~200μg/L;检出限0.03μg/L;相对标准偏差为3·88%。应用本方法对广州大田山垃圾填埋场的垃圾渗沥液中的双酚A进行了测定。     

液相色谱-串联质谱法测定小型家用电器塑料部件中双酚A

建立了小型家用电器塑料部件中双酚A的液相色谱-串联质谱(LC-MS/MS)检测方法。采用快速溶剂萃取仪对样品进行萃取,以Sep-Pak C18固相萃取柱净化,甲醇-水(含有0.05%氨水)混合液作为流动相,负离子模式下进行MS/MS检测。结果表明: 该方法在5～100 μg/L范围内线性关系良好,相关系数(r2)为0.9991。在10、25和75 μg/kg 3个添加水平下,双酚A的平均回收率为95.2%～109.7%,相对标准偏差均小于3.8%,检出限为10 μg/kg。该方法操作简便,灵敏度高,适用于家用电器塑料部件中双酚A的残留分析。     

Solvent extraction separation of In/III/-Tl/III/ and Hg/II/-Cd/II/-Co/II/ with sulphoxides

Solvent extraction studies have been made on some metals: In/III/-Tl/III/ and Hg/II/-Cd/II/-Co/II/, from ammonium thiocyanate solutions by dialkyl sulphoxides. Separation of these metals from one another can be achieved by suitable choice of the extracted conditions. The nature of the extractable metal species has been elucidated.     

Synthesis of chlorobis/β-diketonato/oxotechnetium/V/ and tris/β-diketonato/technetium/III/ complexes

Chlorobis/-diketonato/ oxotechnetium/V/ complexes [TcOCl/-dik/₂, -diketone=acetylacetone, benzoylacetone and dibenzoylmethane] were newly synthesized using macroamount of⁹⁹Tc. These complexes were further separated into geometrical isomers. Furthermore, an improvement of the yields for the syntheses of tris/-dike-tonato/technetium/III/ complexes [Tc/-dik/₃, -diketone=acetylacetone, benzoylacetone and 2-thenoyltrifluoroacetone] was examined using Tc/III/-thiourea complexes as a starting material.     

Crystal structure of Na3PO4 · 12H2O

The crystal structure of trisodium monophosphate hemihydrate was determined. The space group is $\text{C2}\text{c}$ and a unit cell contains eight formula units. The unit cell dimensions of $\text{Na}{}_3\text{PO}{}_4\text{·}\text{1}\text{2}\text{H}{}_2\text{O}$ are a = 9.631(3), b = 5.416(2), c = 16.938(8) Å, β = 102.60(5)°. The final R value is 0.027 for a set of 1430 independent reflections. This atomic arrangement is mainly a three-dimensional network of distorted NaO₆ octahedra. The hydrogen bonding scheme is given.     

Simultaneous propane dehydrogenation andco2hydrogenation overCrOx/SiO2catalyst

Summary Single reverse water-gas shift (RWGS) and dehydrogenation of propane with CO₂(DH-CO₂) reactions in the presence and absence of the CrO_x/SiO₂ catalyst have been studied between 673 and 873 K. It was found that the CrO_x/SiO₂ catalyst is active both in the dehydrogenation of propane and in the RWGS reactions. The obtained results suggest that the dehydrogenation of propane to propene in the presence of CO₂on CrO_x/SiO₂can be facilitated by the RWGS reaction.</o:p>     

Direct synthesis of dimethyl carbonate ?from CH3OH AND CO2 by H3PW12O40/CexTi1-xO2 catalyst

Summary Ce_xTi_1-xO₂ and H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ catalysts were prepared using a sol-gel method, and applied to the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ showed a better catalytic performance than the corresponding Ce_xTi_1-xO₂, due to the bifunctional catalysis of Br?nsted acid sites (provided by H₃PW₁₂O₄₀) and base sites (provided by Ce_xTi_1-xO₂). H₃PW₁₂O₄₀/Ce_0.1Ti_0.9O₂ showed the highest catalytic performance among the H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ catalysts.     

Oxygen defect K2NiF4-type oxides: The compounds La2−xSrxCuO4−x2+δ

Oxygen defect K₂NiF₄-type oxides $\text{La}{}_{\mathrm{2?x}}\text{Sr}{}_{\mathrm{x}}\text{CuO}{}_{\mathrm{<mtext>4?</mtext><mtext>x</mtext><mtext>2</mtext><mtext>+\delta </mtext>}}$ have been synthesized for a wide composition range: 0 ≤ x ≤ 1.34. From the X-ray and electron diffraction study three domains have been characterized: orthorhombic compounds with La₂CuO₄ structure for 0 ≤ x < 0.10, tetragonal oxides similar to LaSrCuO₄ for 0.10 ≤ x < 1 and several superstructures derived from the tetragonal cell ( with n = 3, 4, 4.5, 5, 6) for 1 ≤ x ≤ 1.34. The compounds corresponding to 0 < x < 1 differ from the other oxides in that they are characterized by the presence of copper with two oxidation states: + 2 and + 3. A model structure for La_0.8Sr_1.2CuλO_3.4, in which copper has only the + 2 oxidation state, and for which the actual cell is tegragonal—a = 18.80₄ Å and c = 12.94 Å—has been established. The particular structural evolution of these compounds is discussed in terms of a competition between the capability of Cu(II) to be oxidized to Cu(III) and the ordering of oxygen vacancies.     

An investigation of the promotional effect of propylene or propane traces on the activity of sulfatedPt/g-Al2O3andPt-Sn/g-Al2O3inCH4combustion

Summary A strong promoting effect of the presence of C₃H₈or C₃H₆was determined for the combustion of CH₄in excess oxygen, over pre-sulfated 1%Pt/g-Al₂O₃and pre-sulfated 1%Pt-2%Sn/g-Al₂O₃catalysts.</o:p>     

A study of the spinel materials LiTi2O4 and Li43Ti53O4 by photoelectron spectroscopy

HeI-excited valence-band ultraviolet photoelectron spectra and MgKα-excited Ti-2p X-ray photoelectron spectra are reported for the spinel materials LiTi₂O₄ and $\text{Li}{}_{\mathrm{<mtext>4</mtext><mtext>3</mtext>}}\text{Ti}{}_{\mathrm{<mtext>5</mtext><mtext>3</mtext>}}\text{O}{}_4$. The presence of a Fermi edge in the ultraviolet photoelectron spectrum of LiTi₂O₄ confirms the metallic nature of this material, although the measured density of states at the Fermi energy is much lower than that expected from an independent-electron interpretation of the magnetic susceptibility. This difference is attributed to a strong interaction of the conduction electrons with the lattice vibrations. The localization of conduction electrons that occurs in the final state in the Ti-2p X-ray photoelectron spectrum of LiTi₂O₄ is attributed to a Coulomb interaction with a core hole.     

LixZryOz三元化合物的制备及表征

采用高温固相法制备了4种高纯度晶相组成的LixZryOz三元化合物,研究了焙烧温度、时间、反应物的种类和初始反应物物质的量比对产物组成的影响,进一步用XRD、SEM及BET分析方法对产物的晶相结构、表面形貌及比表面积进行了表征.实验结果表明,Li2CO3与ZrO2在适当条件下可以合成得到单斜相Li3ZrO3;以LiOH替代Li2CO3,在适当条件下可以分别合成得到四方相Li2ZrO3和三斜/单斜相Li6Zr2O7;进一步以Zr(NO3)4·5H2O代替Zr02,可将单斜相Li6Zr2O7的制备时间由96 h缩短至24 h.SEM照片显示产物硬团聚明显,粒径分布在1～10μm间,BET分析表明样品比表面积处于1.0～9.0 m2·g-1间分布,反应过程中锂的过量以及长时间高温焙烧是引起产物粒径长大和产生硬团聚的主要原因.     

Synthesis and characterization of Ti1−2xNbxNixO2−x/2 solid solutions

Doped-rutile has been traditionally used in ceramic pigments for its intense optical properties. In this paper, we compare the classical ceramic synthesis of Ti_1−2xNb_xNi_xO_2−x/2 system with the sol-gel methodology, which allows a reduction of the anatase-rutile transformation temperature. The composition was optimised in order to obtain a unique rutile phase with the minimum amount of pollutant Ni(II) and enhanced chromatic coordinates. Incorporation of the doping ions in the rutile structure was corroborated by XRD and Rietveld refinements. The species responsible for the colour mechanism were studied by different techniques. UV-VIS spectroscopy showed the characteristic features of Ni²⁺ ions, whose existence was corroborated by EPR and magnetic measurements. From these results, (Ni,Nb)doped-TiO₂ powder samples can be now shaped as thin films, monoliths, etc. by using sol-gel methodology without modifying their properties. This study introduces new possibilities of coloured TiO₂-based solid solutions in new combined advanced applications (colouring agent and photocatalyst, etc.).