改性聚氨酯固相微萃取吸附材料的合成及光谱分析

以羟基硅油、甲苯-2,4-二异氰酸酯（TDI）、聚己二酸乙二醇酯和1,6-己二醇为原料,以辛酸亚锡为催化剂,环己酮为溶剂,合成了有机硅-聚氨酯聚合物固相微萃取吸附材料。采用红外光谱法对聚合产物进行了结构表征。建立了分光光度法测定有机硅-聚氨酯共聚物中游离异氰酸酯基（NCO）含量的定量分析方法,吸光度与异氰酸基含量呈线性关系,相关系数为R2=0.9996。该方法相对标准偏差小于5%,回收率为99.4%～105%。考察了显色剂用量、体系的酸度、显色时间等因素对NCO测定结果的影响。     

紫外光度法测定水中石油类物质的方法改进

针对紫外分光光度法测定水中石油类污染物时遇到的标准油选择和测定结果与红外光度法不一致的问题,研究了用红外光谱法中使用的混合烃作为标准物质、用硅酸镁吸附柱去除动植物油的可行性。结果表明,用混合烃作为紫外分光光度法的标准物质是可行的;用硅酸镁吸附柱可有效去除紫外分光光度法中动植物油对测定的干扰。石油醚萃取液经硅酸镁吸附柱吸附动植物油后,紫外分光光度法的测定结果与红外光谱法测定结果相一致。     

蛋白质增敏钼-邻苯二酚紫体系的研究及应用

在pH=2.8的clark-lubs缓冲介质中,牛血清白蛋白能显著增敏钼-邻苯二酚紫的显色体系,据此建立了分光光度法测定钼的新方法。仔细考察了反应酸度、邻苯二酚紫浓度、牛血清白蛋白浓度及反应时间等因素对测定的影响。最大吸收波长在680 nm处,与钼-邻苯二酚紫体系相比,红移了120 nm。10 mL溶液中,钼质量在0～40μg范围内服从比尔定律,测定的表观摩尔吸光系数为2.11×104L/(mol.cm)。所拟方法简便、快速、灵敏度高,用于合金钢样品中微量钼的测定,结果与认定值一致。     

邻苯三酚红-溴化十六烷基吡啶分光光度法测定农业样品中铁

对铁 ( )与邻苯三酚红的显色反应条件进行了研究。在溴化十六烷基吡啶存在下 ,于 p H 5 .0的乙酸-乙酸钠缓冲介质中 ,铁 ( )与邻苯三酚红形成绿色配合物 ,其最大吸收波长为 64 8nm,表观摩尔吸光系数为 3 .2 0× 10 4L· (mol·cm) -1 ,铁 ( )浓度在 0～ 2 5 μg· (2 5 m L) -1范围内符合比耳定律。在酒石酸钾钠和氟化钠的存在下 ,方法具有良好的选择性 ,应用于粮食、植株样品和环境水样中微量铁的测定 ,结果满意     

车间空气中氨浓度测定方法改进

用纳氏试剂分光光度法代替纳氏试剂目测比色法测定车间空气中氨浓度，并采用了单管直接抽取空气样品的方法，使操作简单。并对分析过程中的干扰因素进行了消除，经过作标准曲线、空白试验和计算方法检测限，证明此方法准确度较高。     

黑茶乙醇提取物以及其抗氧化性的研究

目的：研究黑茶的抗氧化性作用.方法：采用溶液超声波提取法提取出黑茶的乙醇提取物,再用分光光度法测定不同浓度的黑茶乙醇提取物对羟基自由基、DPPH自由基的抑制率以及还原能力.结果：在一定范围内,随着黑茶提取物的含量增加其对自由基的抑制作用以及还原能力都逐渐增强.当提取液体积为0.20 mL时,提取液对羟基自由基的抑制达到最大为51.70％.在黑茶提取液体积达到0.16 mL时,其对DPPH自由基的抑制达到最高为87.44％.黑茶提取物的还原能力,在一定浓度范围内呈现正相关性A=0.040 3＋2.007 4V,相关系数为0.999 6.结论：黑茶乙醇提取物具有较好的抗氧化性.     

紫外分光光度法测定双酚 AF

碱性条件下,双酚 AF 紫外光谱的吸收峰会发生红移,从225 nm 移至248 nm,据此建立了简单、灵敏、快捷、选择性较好的测定双酚 AF 可见分光光度法,并研究了氨水用量、反应时间、反应温度对吸光度的影响。结果表明：双酚 AF 的最大吸收波长为248 nm,线性范围是0.6～7．2 mg／L,相关系数 r 为0.9998,为检测食品塑料包装中双酚 AF 的残留提供了新的实验方法。     

虎红定量光度法测定乳糖酸阿奇霉素

基于乳糖酸阿奇霉素与虎红形成离子缔合物,该离子缔合物的最大吸收在波长560nm处,此处其吸光度与质量浓度呈现线性关系,提出了一种测定乳糖酸阿奇霉素的定量光度法。详细研究了该显色反应的各种影响条件,在条件优化基础上建立了乳糖酸阿奇霉素的测定方法,结果表明乳糖酸阿奇霉素质量浓度的线性范围在5.0~25.0g·L-1之间。所拟方法成功地应用于乳糖酸阿奇霉素注射剂的测定。     

Origin of Hole-Trapping States in Solution-Processed Copper(I) Thiocyanate and Defect-Healing by I2 Doping

Solution-processed copper(I) thiocyanate (CuSCN) typically exhibits low crystallinity with short-range order; the defects result in a high density of trap states that limit the device's performance. Despite the extensive electronic applications of CuSCN, its defect properties are not understood in detail. Through X-ray absorption spectroscopy, pristine CuSCN prepared from the standard diethyl sulfide-based recipe is found to contain under-coordinated Cu atoms, pointing to the presence of SCN⁻ vacancies. A defect passivation strategy is introduced by adding solid I₂ to the processing solution. At small concentrations, the iodine is found to exist as I⁻ which can substitute for the missing SCN⁻ ligand, effectively healing the defective sites and restoring the coordination around Cu. Computational study results also verify this point. Applying I₂-doped CuSCN as a p-channel in thin-film transistors shows that the hole mobility increases by more than five times at the optimal doping concentration of 0.5 mol.%. Importantly, the on/off current ratio and the subthreshold characteristics also improve as the I₂ doping method leads to the defect-healing effect while avoiding the creation of detrimental impurity states. An analysis of the capacitance-voltage characteristics corroborates that the trap state density is reduced upon I₂ addition.     

Development of a water-in-oil-in-water multiple emulsion system integrating biomimetic aqueous-core lipid nanodroplets for protein entity stabilization. Part II: process and product characterization

The aqueous-core enclosed in lipid nanoballoons integrating multiple emulsions of the type water-in-oil-in-water mimic, at least in theory, the environment within viable cells, thus being suitable for housing hydrophilic protein entities such as bioactive proteins, peptides and bacteriophage particles. This study reports a complete physicochemical characterization of optimized biomimetic aqueous-core lipid nanoballoons housing hydrophilic (BSA) protein entities, evolved from a statistical 2³×3¹ factorial design study (three variables at two levels and one variable at three levels) that was the subject of the first paper of a series of three, aiming at complete stabilization of the three-dimensional structure of protein entities attempted via housing the said molecular entities within biomimetic aqueous-core lipid nanoballoons integrating a multiple (W/O/W) emulsion. The statistical factorial design followed led to the production of an optimum W/O/W multiple emulsion possessing quite homogeneous particles with an average hydrodynamic size of (186.2?±?2.6) nm and average Zeta potential of (?36.5?±?0.9) mV, and exhibiting a polydispersity index of 0.206?±?0.014. Additionally, the results obtained for the diffusion coefficient of the lipid nanoballoons integrating the optimized W/O/W multiple emulsion were comparable and of the same order of magnitude (10^?12 m² s^?1) as those published by other authors since, typically, diffusion coefficients for molecules range from 10^?10 to 10^?7 m² s^?1, but diffusion coefficients for nanoparticles are typically of the order of magnitude of 10^?12 m² s^?1.