B-藻红蛋白在表面活性剂中的光谱性质

对标题化合物在3种不同类型的表面活性剂中的可见吸收光谱进行了研究.实验条件下,阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)使B-藻红蛋白的最大吸收峰由545 nm蓝移至506 nm,随CTAB浓度增加,最大吸收值显著下降.阴离子表面活性剂十二烷基硫酸钠(SDS)在低浓度时对B-藻红蛋白的特征吸收峰形影响不大,当SDS的浓度2.0×10-3mol/L时,B-PE在564 nm的吸收峰消失.非离子表面活性剂Triton X-100对B-藻红蛋白的吸收峰形没有产生明显影响,并使吸收峰强度均有所增加.还初步探讨了B-藻红蛋白在3种表面活性剂中光谱变化的机理.     

铜(Ⅱ)-曙红B-洛美沙星的共振瑞利散射的研究与应用

在pH 4.0的BR缓冲介质中,洛美沙星能与铜(Ⅱ)形成螯合阳离子,再通过静电引力和疏水作用,与曙红B阴离子形成缔合物,导致共振瑞利散射(RRS)显著增强。在最大RRS峰380 nm处,散射光增强值(ΔI)与洛美沙星的浓度成正比,据此建立了共振光散射法测定洛美沙星,线性范围为8.99×10-8～3.00×10-6mol/L,检出限(3Sb/k)为2.69×10-8mol/L。该法用于检测牛奶中洛美沙星的含量,并取得满意结果。该方法简单、快速、灵敏度高。     

溴甲酚紫光度法测定阳离子表面活性剂的含量

在pH 6.40的NaH2PO4-Na2HPO4缓冲液中,溴甲酚紫与十六烷基溴化吡啶(CPB)和十六烷基三甲基溴化铵(CTAB)反应,形成离子缔合物,最大褪色波长均在588 nm处。CPB和CTAB的浓度分别在1.5×10-6mol/L~1.8×10-5mol/L和1.0×10-6mol/L~1.6×10-5mol/L遵守比耳定律,表观摩尔吸光系数分别为2.83×104L.mol-1.cm-1和3.23×104L.mol-1.cm-1,检测限分别为5.12×10-7mol/L和4.75×10-7mol/L,回收率为97.4%~104.1%。方法有高的灵敏度和良好的选择性,可用于水样中阳离子表面活性剂的测定。     

基于阳离子表面活性剂缔合微粒共振瑞利散射光谱法测定痕量O_3

以pH=4.0 HAC-NAAC缓冲溶液为介质,用硼酸碘化钾溶液(BKI)作为O3吸收剂。O3将I-氧化生成为I2,溶液中过量的I-与I2又可形成I-3,有阳离子表面活性剂(CS)如氯代十六烷基吡啶(CPCI),溴代十四烷基吡啶(TPB),十六烷基三甲基溴化铵(CTMAB),十四烷基苄基二甲基氯化铵(TDMAC)存在时,CS与I-3形成稳定的(CS-I3)n缔合微粒,在470 nm处有一个较强的共振瑞利散射峰(RRS),随着O3浓度的增大,体系中的I-3增多,I-3与CS形成的(CS-I3)n缔合微粒越多,470 nm处的RRS强度I增强,O3浓度与其增强值ΔI成线性关系,各体系的线性范围分别为15~50,50~100,5~25,1~50μmol·L-1,回归方程分别为ΔI=8.81c-4.01,ΔI=5.44c-3.11,ΔI=15.39c-1.55,ΔI=16.88c+0.51,检出限分别为4.9,12,2.85,0.56μmol·L-1O3。实验考察了共存物质的影响,当O3浓度为2.5×10-6mol·L-1,相对误差在±10%内时,4.0×10-5mol·L-1Hg2+,8.7×10-5mol·L-1Fe3+,5.0×10-5mol·L-1Ca2+,2.5×10-5mol·L-1Zn2+和Cu2+,2.8×10-6mol·L-1Pb2+和Cr3+,4.2×10-5mol·L-1Mg2+,Mn2+和Ba2+对体系的测定无干扰。说明该方法具有良好的选择性。选用TDMAC体系检测空气中的O3,结果令人满意。采用激光散射技术研究了(TDMAC-I3)n缔合微粒体系的粒径分布。当通入O3后,过量KI与O3反应形成I-3,I-3与TDMAC反应生成(TDMAC-I3)n缔合微粒,其粒径集中分布在1 106~3 091 nm之间。     

吖黄素盐酸盐共振瑞利散射光谱法测银离子含量

提出了共振瑞利散射光谱技术(RRS)测定Ag~+含量的新方法。在p H为2. 87～8. 95的Britton-Robinson(B-R)缓冲溶液中,吖黄素盐酸盐(AH,Acriflavine hydrochlorde)与Ag~+结合生成配合物,使溶液的共振瑞利散射(RRS)增强,并且在321 nm、489 nm处的散射峰强度显著增加。以321 nm为测定波长,Ag~+的浓度在0. 05～10 mg/L范围内,与RRS强度变化有良好的线性关系,对Ag~+的检出限(3σ)达0. 019 mg/L。研究了反应的适宜条件和影响因素,并用于环境水样中Ag~+含量的测定,回收率为93. 5%～106%。     

钴卟啉轴向配位反应的紫外可见及圆二色谱研究

用紫外-可见光谱和圆二色谱研究了氯乙酸胆甾酯钴卟啉和桥联冠醚钴卟啉在CHCl3中的光谱行为,探讨了氯乙酸胆甾酯钴卟啉和桥联冠醚钴卟啉与咪唑、苯骈咪唑轴向配位前后的光谱变化。实验结果表明:在反应体系中不同的配体具有不同的最佳浓度:氯乙酸胆甾酯钴卟啉体系中,咪唑、苯骈咪唑的最佳浓度分别为7.5×10-4mol/L,2.5×10-4mol/L,低于最佳浓度时有利于增强CD光谱的强度和对称性,高于最佳浓度则减弱了CD光谱的强度并且使峰形变复杂;同时卟啉和咪唑类分子的结构均对反应体系的紫外-可见光谱和圆二色光谱的峰形、强度和波长产生影响。     

基于多巴胺共振散射光谱法测定牛奶中的三聚氰胺

在氢氧化钠介质中,氯金酸与多巴胺发生氧化还原反应生成金纳米粒子而使体系在519. 4 nm处产生一个较强的共振散射峰。当加入三聚氰胺时,多巴胺和三聚氰胺通过氢键结合并形成稳定的多氢键化合物,使得结合的多巴胺还原能力降低而不能还原氯金酸,阻碍金纳米粒子的形成,导致体系519. 4 nm处的共振散射峰强度降低。据此建立了检测三聚氰胺的共振散射光谱法。在优化的实验条件下,c(三聚氰胺)在8. 33×10-7~1. 67×10-5mol/L范围内与该共振散射峰强度的降低值(ΔI519. 4 nm)呈良好线性关系,其相关系数为0. 996 1,检出限为2. 1×10-7mol/L。将该共振散射光谱法用于牛奶制品中的三聚氰胺的测定,回收率为96. 0%~108. 0%,相对标准偏差为1. 3%~2. 7%。     

基于复红作探针的双波长共振瑞利散射法测定药物中的盐酸米多君

以复红为探针建立了快速测定药物中盐酸米多君的高灵敏双波长共振瑞利散射(RRS)法。在pH 3. 46的酸性溶液中,复红与十六烷基溴化吡啶鎓及盐酸米多君作用生成三元离子缔合物,使RRS信号显著增强并产生具有双峰的新的RRS光谱。最大RRS峰位于620 nm,次大RRS峰位于370 nm,在此二波长处的RRS增强强度与0. 009～0. 35 mg/L盐酸米多君的质量浓度呈线性关系,检出限分别为0. 006 2 mg/L(370 nm)和0. 005 8 mg/L(620 nm),当用双波长叠加RRS法测定时,检出限为0. 003 0 mg/L。还研究了三元缔合反应的适宜条件、共存物质的影响及双波长RRS法的光谱特征。该方法可用于市售盐酸米多君药片中盐酸米多君含量的测定,回收率和相对标准偏差RSD%(n=5)分别为98. 3%～102%和1. 2%～1. 8%。     

曙红亚甲基蓝分光光度法测定水中阳离子表面活性剂

采用分光光度法测定水样中阳离子表面活性剂的含量。在弱酸性的HCl-NaAc缓冲介质中,阳离子表面活性剂十六烷基溴化吡啶(CPB)以及十六烷基三甲基溴化铵(CTAB)能与曙红亚甲基蓝反应,形成离子缔合物,后者的最大吸收波长分别为660 nm和658 nm,且阳离子表面活性剂的浓度与溶液的显色程度呈良好线性关系。在最大吸收波长处,CPB和CTAB的浓度分别在0~2.10×10-5mol/L和0~1.98×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为1.79×104L/(mol.cm)和1.38×104L/(mol.cm),检出限分别为8.27×10-7mol/L和9.88×10-7mol/L,平均回收率为99.5%~102.6%。方法具有较高的灵敏度和良好的选择性,可用于水样中阳离子表面活性剂的测定。     

CdTe/CdS量子点荧光猝灭法测定十六烷基三甲基溴化铵

以巯基乙酸为稳定剂,在水溶液中合成了CdTe/CdS量子点,基于十六烷基三甲基溴化铵(CTAB)与CdTe/CdS量子点的荧光猝灭作用,建立了用CdTe/CdS量子点作为荧光探针测定水中微量十六烷基三甲基溴化铵的新方法。考察了缓冲溶液、pH和量子点浓度等因素对体系荧光强度的影响。结果表明,在pH为6.8的磷酸二氢钾-硼砂缓冲溶液中,当CdTe/CdS量子点浓度为3.75×10-4mol/L时,体系的相对荧光强度与十六烷基三甲基溴化铵的浓度在5.49×10-7~4.12×10-5mol/L范围内呈现良好的线性关系,相关系数为0.999 7,检出限为5.43×10-8mol/L。方法应用于水中微量十六烷基三甲基溴化铵测定,回收率在96.7%~101.7%。     

长春地辛-赤鲜红体系的吸收、荧光和共振散射光谱的研究及其分析应用

在pH 2.7的BR缓冲溶液中,长春地辛与赤鲜红相互作用形成离子缔合物,导致其吸收光谱的变化,荧光光谱猝灭,以及共振瑞利散射(RRS)光谱显著增强.其吸收峰位于520 nm,荧光峰的最大激发波长和发射波长分别位于523和551 nm,最大RRS峰位于325 nm;且吸光度增加、荧光光谱猝灭程度以及散射光谱增强程度均与长春地辛浓度增加呈线性关系,其线性范围分别为:0.8～4.0、0.2～3.0、0.08～2.0 μg/mL,检出限分别为:0.089、0.072、0.019 μg/mL.据此可建立分析测定痕量长春地辛的新方法,将共振瑞利散射法用于尿样中长春地辛含量的快速测定,结果满意.对反应机理进行了初步探讨.     

双子表面活性剂为乳化剂时PS乳液的制备与形貌研究

以双子表面活性剂[磺酸盐型双子表面活性剂(GS)、磺酸型双子表面活性剂(GSA)]、单子表面活性剂[十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS)]作为乳化剂,采用透射电镜(TEM)、凝胶渗透色谱(GPC)等方法重点研究了GS对苯乙烯(St)乳液聚合反应、聚苯乙烯(PS)乳胶粒子的形状、尺寸大小及其分布等影响。结果表明:当m(St)∶m(GS)=5:1、乳液聚合温度为80℃时,PS乳胶粒子的平均粒径为27.92 nm,粒径分布系数为0.154;与传统单子表面活性剂相比,以双子表面活性剂为乳化剂时,所得PS乳液的粒子尺寸更小、尺寸分布更窄以及相对分子质量更高,并且乳液中出现了异形乳胶粒子。     

Electrospinning of chitosan-poly(ethylene oxide) blend nanofibers in the presence of micellar surfactant solutions

Nanofibers were fabricated by electrospinning a mixture of cationic chitosan and neutral poly(ethylene oxide) (PEO) at a ratio of 3:1 in aqueous acetic acid. Chitosan ((1 → 4)-2-amino-2-deoxy-β-d-glucan) is a multifunctional biodegradable polycationic biopolymer that has uses in a variety of different industrial applications. Processing conditions were adjusted to a flow rate of 0.02 ml/min, an applied voltage of 20 kV, a capillary tip-to-target distance of 10 cm and a temperature of 25 °C. To further broaden the processing window under which nanofibers are produced, surfactants of different charge were added at concentrations well above their critical micellar concentrations (cmc). The influence of viscosity, conductivity and surface tension on the morphology and physicochemical properties of nanofibers containing surfactants was investigated. Pure chitosan did not form fibers and was instead deposited as beads. Addition of PEO and surfactants induced spinnability and/or yielded larger fibers with diameters ranging from 40 nm to 240 nm. The presence of surfactants resulted in the formation of needle-like, smooth or beaded fibers. Compositional analysis suggested that nanofibers consisted of all solution constituents. Our findings suggest that composite solutions of biopolymers, synthetic polymers, and micellar solutions of surfactants can be successfully electrospun. This may be of significant commercial importance since micelles could serve as carriers of lypophilic components such as pharmaceuticals, nutraceuticals, antimicrobials, flavors or fragrances thereby further enhancing the functionality of nanofibers.     

阳离子型Gemini表面活性剂对交联聚合物溶液性质的影响

采用核微孔滤膜过滤实验、落球粘度计及动态光散射法,研究了阳离子型Gemini表面活性剂对交联聚合物溶液(LPS)的封堵性能、粘度及交联聚合物线团(LPC)大小的影响。结果表明,加入50 mg/L和100 mg/L的Gemi-ni表面活性剂后,LPS对核微孔滤膜的封堵性能增加,但是当Gemini表面活性剂质量浓度为200 mg/L时,LPS对孔径为1.2μm的核孔膜的封堵性能变化不大。LPS-Gemini表面活性剂复合体系的粘度低于不加表面活性剂的交联聚合物溶液。动态光散射法测得LPS-Gemini表面活性剂复合体系中LPC的平均流体力学半径为180 nm,比不加表面活性剂的LPS中的LPC的粒径小。     

锌酞菁的微波合成及牛白蛋白测定研究

以邻苯二腈、硫酸锌为原料,采用微波固相法合成了锌酞菁。将锌酞菁磺化所得的磺酸基锌酞菁溶液与牛白蛋白作用将导致共振瑞利散射显著增强。在470nm处存在一共振散射强峰,牛白蛋白在0.25～20μg/mL的浓度范围内与散射强度（ΔI）呈线性关系,磺酸基锌酞菁溶液对牛白蛋白的检测限为0.17μg/mL,并且方法有较好的选择性。由此建立一种用共振散射光谱测定牛白蛋白的简便、快速的新方法。     

表面活性剂在纳米氧化铅粉体合成中的应用

在PbAc4与Na2CO3反应体系中，加入表面活性剂（SAA）作为胶团分散剂，实验结果表明：随SAA质量分数增大，产物四氧化三铅（Pb3O4）粒径逐渐变小，当SAA质量分数达到一定（临界下限）值时，就可以得到纳米级Pb3O4；当SAA质量分数达到一定（监界上限）值时，Pb3O4粒度不再变小。复配表面活性剂质量分数下限为3．0％、上限为5．2％时，红丹粒径最小，平均粒度25nm，为单分散球形粒子。非离子表面活性剂质量分数下限为4．1％、上限5．2％，可得到片状纳米Pb3O4粒子。阴离子表面活性质量分数下限3．1％，上限5．2％，纳米Pb3O4粒子为串珠状。     

Some new developments in surfactant analysis

Three new analytical methods for surfactants have been developed and evaluated, and the stoichiometry in cationic titration of a dianionic surfactant has been determined. The three methods include: (a) a rapid method for pyrolytic cleavage of hydrophobic groups from surfactants to hydrocarbons, which can be used for quantitative identification of the hydrophobic groups; (b) a molecular weight method for alkylphenoxy and alkoxy polyethoxylates based on sulfation followed by cationic titration; and (c) a microcationic titration method designed for low levels (1–10 microequivalents) of anionic surfactants, which possesses certain advantages over conventional methods. Previously stoichiometry in cationic titration has been reported only for monoanionic surfactants. In a study of a dianionic surfactant,n-octadecylbutane 1,4-disulfate, each sulfate group was found to react in a 1:1 equivalent ratio with a cationic titrant.     

尿微量白蛋白检测新方法研究及临床评价

研究了吖啶橙(AO)与人血白蛋白(HSA)相互作用所引起的共振瑞利散射(RRS)光谱,在pH7.87~8.10范围内,加入HSA导致AO共振瑞利散射剧烈增强,在λem=λex=525 nm处,存在RRS增强峰,其散射光强度增加值与蛋白质的浓度呈线性关系,据此建立了一种测定蛋白质的RRS法,方法的线性范围为0~10.0 mg/L,检出限8.1μg/L。对共振瑞利散射法(RRS)测定尿微量白蛋白的方法进行临床评估,旨在为尿微量白蛋白测定选择一种简便快速、准确和易推广的方法。95例糖尿病患者及50名对照均留取8 h尿样本,用RRS和RIA法测定,并进行比较和分析。结果显示,RRS和RIA尿微量白蛋白测定方法均具有高精密度、高准确性,两种方法的结果明显相关。与RIA法比较,RRS法简便、快速,没有放射性污染,且仪器、试剂易得,比较适合临床常规实验室应用。     

Polymer/surfactant interactions

Polyelectrolytes and oppositely charged surfactants form precipitation complexes which, in many cases, can be completely resolubilized by excess surfactant. In general, maximum precipitation appears to correspond to a single layer of surfactant adsorbed on the polymer, and the resolubilized form to a double layer of surfactant. Prior to formation of the latter, the complexes are highly surface active. An analysis of the solubility diagrams of a cationic hydroxyethyl cellulose derivative, and a homologous series of sodium alkyl sulfates, has provided a value of the adsorption energy, Φ, of these surfactants into the first layer. The value of Φ, viz., 1.1 kT per CH₂ group, is somewhat higher than the corresponding value for micelle formation. Studies with a number of surfactants show that polymer/surfactant interaction is most favorable (a) the longer the hydrocarbon chain of the surfactant, (b) the straighter the chain, and (c) when the head group is terminal to the chain. Departures from these conditions reduce the extent of interaction and render difficult resolubilization of the complex. From results on a range of polymers, it is concluded that resolubilization of the precipitated complex is also difficult if the charge density of the polymer is too high.     

The adsorption behavior of dialkyl dimethyl ammonium chloride-nonionic surfactant binary systems

From the practical standpoint of fabric softener formulation, a comparative study was made on adsorption behavior toward fabrics of binary systems consisting of di(hydrogenated tallow) dimethyl ammonium chloride (purified Arquad 2HT) and typical polyoxyethylenated nonionic surfactants which are commonly used as auxiliary agents for softeners. Soxhlet extraction of treated fabrics and quantitative analysis by high-performance liquid chromatography (HPLC) gave significant results indicating many of these nonionic surfactants, assumed to be inherently unadsorbable in rinse-cycle treatment, were highly adsorbable even at a high bath ratio by being applied with the water-insoluble cationic surfactant. Moreover, it was also disclosed that the hydrophobic structure of nonionic surfactants is another factor, other than hydrophobicity, determining adsorption. Furthermore, the mechanism of this nonionic adsorption was elucidated on the basis of results of structural analyses of binary dispersions by differential scanning calorimetry (DSC), X-ray diffraction, electron spin resonance spectroscopy (ESR) and transmission electromicroscopy (TEM) in addition to partition measurements of the surfactants into the dispersed and the continuous aqueous phases. It was concluded that the primary driving force for this nonionic adsorption is an association with the lamellar of Arquad 2HT and that the cationic vesicles act as “anchors” in adsorption.