中草药中有机磷及氨基甲酸酯类农药残留量的GC-MS测定

气相色谱-质谱法同时测定中草药中多种有机磷及氨基甲酸酯类农药残留量.采用V(乙腈)∶V(丙酮)＝3∶7混合溶剂微波辅助提取,弗罗里硅土和中性氧化铝层析柱净化,气相色谱-质谱(GC-MS)联用检测,农药混标在0.01～1.0 μg/mL范围内线性良好,在0.5、0.1、0.05 μg/mL 3个水平添加平均回收率分别为86.5%～110.6%、81.2%～108.3%和72.9%～122.3%,相对标准偏差分别为2.6%～8.3%、4.6%～9.7%和2.3%～10.7%.     

微波辅助快速制备2D/1D ZnIn2S4/TiO2 S型异质结及其光催化制氢性能

The threat and global concern of energy crises have significantly increased over the last two decades. Because solar light and water are abundant on earth, photocatalytic hydrogen evolution through water splitting has been considered as a promising route to produce green energy. Therefore, semiconductor photocatalysts play a key role in transforming sunlight and water to hydrogen energy. To date, various photocatalysts have been studied. Among them, TiO₂ has been extensively investigated because of its non-toxicity, high chemical stability, controllable morphology, and high photocatalytic activity. In particular, 1D TiO₂ nanofibers (NFs) have attracted increasing attention as effective photocatalysts because of their unique 1D electron transfer pathway, high adsorption capacity, and high photoinduced electron–hole pair transfer capability. However, TiO₂ NFs are considered as an inefficient photocatalyst for the hydrogen evolution reaction (HER) because of their disadvantages such as a large band gap (~3.2 eV) and fast recombination of photoinduced electron–hole pairs. Therefore, the development of a high-performance TiO₂ NF photocatalyst is required for efficient solar light conversion. In recent years, several strategies have been explored to improve the photocatalytic activity of TiO₂ NFs, including coupling with narrow-bandgap semiconductors (such as ZnIn₂S₄). Recently, microwave (MW)-assisted synthesis has been considered as an important strategy for the preparation of photocatalyst semiconductors because of its low cost, environment-friendliness, simplicity, and high reaction rate. Herein, to overcome the above-mentioned limiting properties of TiO₂ NFs, we report a 2D/1D ZnIn₂S₄/TiO₂ S-scheme heterojunction synthesized through a microwave (MW)-assisted process. Herein, the 2D/1D ZnIn₂S₄/TiO₂ S-scheme heterojunction was constructed rapidly by using in situ 2D ZnIn₂S₄nanosheets decorated on 1D TiO₂ NFs. The loading of ZnIn₂S₄ nanoplates on the TiO₂ NFs could be easily controlled by adjusting the molar ratios of ZnIn₂S₄ precursors to TiO₂ NFs. The photocatalytic activity of the as-prepared samples for water splitting under simulated solar light irradiation was assessed. The experimental results showed that the photocatalytic performance of the ZnIn₂S₄/TiO₂ composites was significantly improved, and the obtained ZnIn₂S₄/TiO₂ composites showed increased optical absorption. Under optimal conditions, the highest HER rate of the ZT-0.5 (molar ratio of ZnIn₂S₄/TiO₂= 0.5) sample was 8774 μmol·g^-1·h^-1, which is considerably higher than those of pure TiO₂ NFs (3312 μmol·g^-1·h^-1) and ZnIn₂S₄nanoplates (3114 μmol·g^-1·h^-1) by factors of 2.7 and 2.8, respectively. Based on the experimental data and Mott-Schottky analysis, a possible mechanism for the formation of the S-scheme heterojunction between ZnIn₂S₄ and TiO₂ was proposed to interpret the enhanced HER activity of the ZnIn₂S₄/TiO₂heterojunctionphotocatalysts.      

横向加热石墨炉的分析性能研究

研究了横向加热石墨炉的恒温性能和分析性能，并与Ｍａｓｓｍａｎｎ型炉进行了比较，结果表明，横向加热石墨炉具有较好的恒温性能，其原子化时间短，原子化温度低，原子吸收信号的占有时间短，特征质量ｍ０值低。     

有机液体化学试剂馏程测定注意事项

对有机液体化学试剂馏程测定过程中应注意的一些问题如加热源选择、蒸馏速度控制、温度计选择、蒸馏收率以及同一样品不同特性测量结果的相关性分析等进行了分析，为正确测定馏程提供经验和依据。     

柴油机烟碳的微波加热燃烧Ⅲ.铜催化剂的影响

柴油机烟碳的微波加热燃烧Ⅲ．铜催化剂的影响吕晓慧马建新李平朱兵刘士宁（华东理工大学工业催化研究所，上海２００２３７）方明刘毅庭（香港科技大学研究中心）关键词柴油机烟碳，微波加热，催化燃烧，铜催化剂作者在前文［１，２］研究了柴油机烟碳的微波加热燃...     

微波辅助提取-GC/MS联用分析苍耳子中油脂成分的研究

采用微波辅助提取-GC/MS联用分析苍耳子中的油脂成分.以V(环已烷):V(丙酮)=1:1为提取溶剂,优化了微波辅助提取的条件.以正二十烷为内标,鉴定出了13种油脂成分,各组分相对保留时间的相对标准偏差(RSD)小于0.15%,相对峰面积的RSD＜3.0%.对不同批次以及不同产地的苍耳子样品进行了对比研究.该方法可用于苍耳子的鉴定和质量控制.     

有序自组装聚合物纳米结构

采用水辅助方法(water-assisted fabrication method),分别以4-十二烷基苯磺酸掺杂的聚苯胺(PANI-DBSA)和聚2-甲氧基-5-(2′-乙烯基-己氧基)苯乙炔(MEH-PPV)两种功能高聚物为成膜材料,冷凝水滴为模板,利用水滴在聚合物溶液表面的自组装,制备出了两种纳米层次以上的蜂窝状有序多孔聚合物薄膜.通过原子力显微镜和共聚焦荧光显微镜对其形貌、电学性质和荧光图像进行了表征.     

微波技术在有机化学反应中的应用

本文介绍了微波技术在干法有机反应、加速有机合成速率及合成短寿命放射性药剂中的应用,概述了微波技术中影响反应速率的因素等,说明了微波特有的能量及快速加热能力在化学反应研究中具有广泛的实际意义。     

表面活性剂的基体辅助激光解吸电离/质谱分析表征

利用基体辅助激光解吸电离／质谱（MALDI－MS）技术对表面活性剂的分析表征进行了详细研究。以2，5－二羟基苯甲酸作为基体，考察MALDI样品制备方法如液滴干燥法、快速干燥法及三明治法对测定结果的影响，发现三明治方法更适合表面活性剂的分析。MALDI可以准确测定离子型表面活性剂的分子量，同时对于非离子型表面活性剂，还可以测定其平均聚合度和分子量的分布。     

微波辅助萃取/气相-质谱联用分析蔬菜中的有机磷农药

 建立了微波辅助萃取 (MAE) /气相 质谱联用法 (GC MS)测定蔬菜样品中二嗪磷、对硫磷、水胺硫磷的分析方法 ,研究了不同溶剂的萃取效率。选择二氯甲烷为萃取溶剂 ,采用二因素三水平的正交设计实验优化了萃取溶剂体积和萃取时间。方法的线性范围分别为二嗪磷和对硫磷 4ng/ g～ 40 0ng/ g、水胺硫磷 2 0ng/ g～ 40 0ng/ g,检出限分别为二嗪磷 0 2 9ng/g、对硫磷 1 70ng/g、水胺硫磷 2 30ng/g。测定 2 0 0 0ng/g和 50 0ng/g加标蔬菜样品 ,回收率为 72 2 %～ 1 0 2 0 % ,RSD为 1 5 %～ 1 1 0 %。。