SOLUBILIZATION OF OIL IN DISCONTINUOUS CUBIC LIQUID CRYSTAL IN POLY(OXYETHYLENE)n OLEYL ETHER SYSTEMS

The structural change of the discontinuous cubic (I₁) phase upon addition of oil (heptane, decane, and hexadecane) is investigated by small-angle x-ray scattering. In polyoxyethylene oleyl ether (C_18.1EO_n) systems having long polyoxyethylene chain (n =19.2, 30.1, and 50.8), the I ₁ phase is formed in a wide concentration range. Only in C_18.1EO_nEO_19.2EO_n systems, the structure of the I₁ phase changes from body-centered to face centered cubic lattice upon addition of oil. According to the analysis of the change in effective cross-sectional area, the solubilization of hexadecane increases the repulsion between polyoxyethylene chains, while solubilization of heptane makes it decrease. The solubilization of decane keeps the repulsion constant. Since the repulsion hampers the curvature change due to the solubilization, the solubilization capacity is in the order, heptane>decane>hexadecane. The oil penetration and nonpenetration into the palisade layer are also discussed in term of the change in the effective volume of the lipophilic part in the surfactant molecule.     

Graphene Decorated with Nickel Nanoparticles as a Sensitive Substrate for Simultaneous Determination of Sunset Yellow and Tartrazine in Food Samples

In this paper, ultrathin graphene (GN) nanosheets were uniformly decorated with nickel (Ni) nanoparticles, as confirmed by scanning electron microscopy and transmission electron microscopy. This GN? Ni hybrid exhibited excellent accumulation and catalytic capacity for the simultaneous detection of sunset yellow and tartrazine, two colorants commonly found mixed in foodstuffs. The electrochemical reaction mechanism of sunset yellow and tartrazine were studied in detail on the GN? Ni nanocomposite modified glassy carbon electrode. In square wave voltammetry measurements, the oxidation peak potentials of sunset yellow and tartrazine were separated by about 250 mV. This novel proposed voltammetric method has good selectivity which was successfully applied for the simultaneous determination of sunset yellow and tartrazine in some food sample extracts.     

低速逆流色谱分离制备栀子黄色素中的藏花素

建立了低速逆流色谱技术(SRCCC)从栀子黄色素中快速分离制备藏花素的方法。两相溶剂系统由叔丁基甲基醚-正丁醇-乙腈-水(2:2.5:1:5, v/v/v/v)组成,以上相为固定相,下相为流动相。在转速为50 r/min和流速为5 mL/min的条件下,从5 g栀子黄色素粗样中分离得到2.47 g藏花素,纯度为96.8%。该方法制备量大、安全、高效,有可能成为工业级分离制备藏花素的一种有效手段。     

超快速液相色谱-串联质谱法测定黄酒和葡萄酒中山梨酸等9种防腐剂和甜味剂

建立了一种专属、灵敏的同时测定黄酒和葡萄酒中安赛蜜、糖精、甜蜜素、阿斯巴甜、苯甲酸、山梨酸、甜菊糖苷、纽甜和脱氢乙酸等9种防腐剂和甜味剂的超快速液相色谱-串联质谱(UFLC-MS/MS)分析方法。不同类型的黄酒和葡萄酒经纯水稀释后,以乙腈和0.01%三氟乙酸-2.5 mmol/L乙酸铵水溶液为流动相,采用梯度洗脱方式在Shim-pack XR-ODSII色谱柱(100 mm×2.0 mm, 2.2 μm)上进行分离,以电喷雾负离子多反应监测(MRM)模式进行质谱分析。实验表明,9种防腐剂和甜味剂在检测范围内均具有良好的线性关系(r2＞0.998);方法的检出限(以信噪比大于3计)为0.03～15.0 μg/L,定量限(以信噪比大于10计)为0.1～50.0 μg/L;在黄酒中的回收率为96.2%～100.5%,相对标准偏差(RSDs)为0.6%～5.4%;在葡萄酒中的回收率为96.0%～104.0%, RSDs为0.7%～4.8%。同时研究了这9种防腐剂和甜味剂的二级质谱特征,阐释了其二级质谱裂解途径。本方法灵敏度高、重现性好、分析速度快,可用于黄酒和葡萄酒中防腐剂和甜味剂的快速确证检测。     

活性嫩黄K-4G在碳糊电极上的电化学研究

研究活性染料常用的嫩黄基础谱带——活性嫩黄K-4G,在具有较小表面积（约为0．07cm^2）的碳糊电极上的电化学响应行为。在-1．0～1．3V的扫描电位窗内,活性嫩黄K-4G显示良好的电氧化还原性质,电极反应速率为吸附控制,电极反应机理为先质子化后电氧化还原。     

达旦黄与氨基糖苷类抗生素相互作用的共振瑞利散射光谱研究及其应用

在弱酸性介质中,达旦黄(TY)和氨基糖苷类抗生素(AGs)本身的共振瑞利散射(RRS)均很微弱。但两者相互作用形成离子缔合物时,溶液的RRS显著增强,并产生了新的RRS光谱。不同AGs的反应产物具有相似的光谱特征,其RRS峰位于278和469 nm;与此同时,它的倍频散射(FDS)也明显增强,并且最大FDS峰位于392 nm处,但二级散射(SOS)变化不明显。RRS较FDS具有较高的灵敏度,而且在一定范围内,AGs的浓度与散射强度(ΔIRRS)成正比。对于不同抗生素的检出限在17.2~23.3μg.L-1之间,用于氨基糖苷类注射液和血清样品中AGs的测定,测得结果的RSD(n=5)值均小于3.5%,回收率在96.3%~97.2%之间。     

Observation of the ν3 Raman band of S3− inserted into sodalite cages

The S₃⁻ radical anion is observed in several systems: non‐aqueous polysulfides solutions, doped alkali halides, ultramarine pigments (UP) for which S₃⁻ is the blue chromophore and S₂⁻ is the yellow one and pigments of zeolite 4A structure. The S₃⁻ ion has C_2V symmetry, and therefore its three vibrational modes should be observed in the Raman and in IR spectra. In resonance Raman spectroscopy, only the symmetric stretching mode ν₁ and the bending mode ν₂ have been observed, whereas the anti‐symmetric stretching mode ν₃ has never been observed whatever the system. In this work, we confirm that ν₃ is not observed in solutions with resonance Raman spectroscopy. However, our investigation of several blue UP, with various concentrations of S₂⁻, shows that there is a superposition of two bands at ca 590 cm⁻¹: the first is assigned to ν (S₂⁻) and the second to ν₃ (S₃⁻). With the 457.9 nm excitation line, for which the resonance conditions are simultaneously fulfilled for S₂⁻ and S₃⁻, the band at ca 590 cm⁻¹ is the sum of the contributions of both ν (S₂⁻) and ν₃ (S₃⁻) vibrations, while, with the 647.1 nm line, which only satisfies the resonance conditions of S₃⁻, the band at ca 584 cm⁻¹ must be assigned only to ν₃ (S₃⁻). Furthermore, ν₃ (S₃⁻) is observed in green UP and in pigments of zeolite structure. The ν₃ vibration of S₃⁻, which is observed neither in polysulfide solutions nor in doped alkali halides in resonance Raman conditions, can therefore be observed when this species is inserted into the β‐cages of the sodalite or of the zeolite 4A structures. So, the band at ca 590 cm⁻¹ cannot always be assigned to S₂⁻ in these systems. This implies that the concentration of S₂⁻ in UP must be reconsidered. Copyright © 2007 John Wiley & Sons, Ltd.     

高效液相色谱法测定红花中的羟基红花黄色素A

建立了菊科植物红花中的主要有效成分羟基红花黄色素A的高效液相色谱定量分析方法。用90 ℃水提取,以甲醇-0.5%磷酸水溶液(体积比为40∶60)为流动相,检测波长400 nm。该方法的最低检出限为4 ng (按S/N=3计)。在羟基红花黄色素A的质量浓度为0.04-0.40 g/L(相当于绝对进样量为0.8-8.0 μg)时线性良好,方法回收率高,重现性好。对26个不同产地和购买地的红花中的羟基红花黄色素A进行了测定,结果表明不同来源的红花中羟基红花黄色素A含量的差异较大。     

A new heteroleptic cuprous complex with strong yellow photoluminescence

In the title heteroleptic cuprous complex, (acetonitrile‐κN)({2‐[2‐(diphenylphosphanyl)phenoxy]phenyl}diphenylphosphane‐κ²P,P′)[2‐(pyridin‐4‐yl‐κN)‐1,3‐benzoxazole]copper(I) hexafluoridophosphate, [Cu(C₃₆H₂₈OP₂)(CH₃CN)(C₁₂H₈N₂O)]PF₆, conventionally abbreviated [Cu(POP)(CH₃CN)(4‐PBO)]PF₆, where POP is the diphosphane ligand {2‐[2‐(diphenylphosphanyl)phenoxy]phenyl}diphenylphosphane and 4‐PBO is the N‐containing ligand 2‐(pyridin‐4‐yl)‐1,3‐benzoxazole, the asymmetric unit consists of a hexafluoridophosphate anion and a whole mononuclear cation, where the Cu^I centre is coordinated by two P atoms from the POP ligand, by one N atom from the 4‐PBO ligand and by the N atom of the coordinated acetonitrile molecule, giving rise to a CuP₂N₂ distorted tetrahedral coordination geometry. The electronic absorption, photoluminescence and thermal stability properties of this complex have been studied on as‐synthesized samples, which had previously been examined by powder X‐ray diffraction. A yellow emission signal is attributed to an excited state arising from metal‐to‐ligand charge transfer (MLCT).     

基于多孔硅Bragg反射镜的光学免疫检测方法

通过共价固定方法将羟基红花黄色素A(HSYA)抗血清蛋白固定到多孔硅Bragg反射镜的孔洞中, 定量分析了不同浓度的羟基红花黄色素A人工抗原与特异性抗羟A多克隆抗体反应后多孔硅Bragg反射镜的反射谱峰位的红移情况. 对比研究了固定阴性血清蛋白的多孔硅Bragg反射镜基底在加入抗原后的反射谱峰位变化情况, 结果表明, 基于多孔硅Bragg反射镜的光学免疫检测具有很好的特异性, 且同目前普遍使用的ELISA方法相比, 具有免标记且检测时间短等优异性能, 同时该研究也为开发红花成分快速检测的免标记多孔硅生物传感器奠定了基础.