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41.
42.
柠檬酸溶解废锂离子电池正极材料的研究 总被引:1,自引:0,他引:1
探求废锂离子电池正极材料LiMn2O4在柠檬酸溶液中的溶解条件,为废旧电池的进一步回收利用奠定基础。采用单因素与正交实验相结合的方法,对废锂离子电池正极材料LiMn2O4在柠檬酸溶液中的溶解条件进行研究,结果表明,废锂离子电池正极材料LiMn2O4在柠檬酸溶液中适宜的溶解条件为:柠檬酸浓度1.0mol.L-1、溶解温度45℃、H2O2加入量5.0%、料液比60g.L-1,在此条件下正极材料LiMn2O4在柠檬酸溶液中的溶解率达到99.56%。对柠檬酸溶解废锂离子电池正极材料LiMn2O4的机理进行了探讨,认为在加入H2O2之前,尖晶石LiMn2O4中的Mn3+发生歧化反应生成Mn2+以及MnO2,而Mn4+在溶液中水解生成MnO2。MnO2与柠檬酸发生氧化还原反应生成丙酮二羧酸及Mn2+。加入H2O2之后,H2O2作为还原剂能够将剩余的MnO2全部还原为Mn2+,使正极材料LiMn2O4在柠檬酸溶液中的溶解率得以提高。 相似文献
43.
Fuqiang Wang Zhonghua Shi Fan Hu Zhengrong Xia Ling Wang 《Analytical and bioanalytical chemistry》2013,405(5):1683-1693
Extraction of phosphopeptides from rather complex biological samples has been a tough issue for deep and comprehensive investigation into phosphoproteomes. In this paper, we present a series of Ti-doped mesoporous silica (Ti-MPS) materials with tunable composition and controllable morphology for highly efficient enrichment of phosphopeptides. By altering the molar ratio of silicon to titanium (Si/Ti) in the precursor, the external morphology, Ti content, internal long-rang order, and surface area of Ti-MPS were all modulated accordingly with certain regularity. Tryptic digests of standard phosphoprotein α- and β-casein were employed to assess the phosphopeptide enrichment capability of Ti-MPS series. At the Si/Ti molar ratio of 8:1, the optimum enrichment performance with admirable sensitivity and capacity was achieved. The detection limit for β-casein could reach 10 fmol, and 15 phosphopeptides from the digest of α-casein were resolved in the spectrum after enrichment, both superior to the behavior of commercial TiO2 materials. More significantly, for the digest of human placenta mitochondria, 396 phosphopeptides and 298 phosphoproteins were definitely detected and identified after enrichment with optimized Ti-MPS material, demonstrating its remarkable applicability for untouched phosphoproteomes. In addition, this research also opened up a universal pathway to construct a composition-tunable functional material in pursuit of the maximum performance in applications. Figure
From human placenta mitochondria to MS 相似文献
44.
Yong Lin Kunbo Wang Yujun Yan Haiyan Lin Bin Peng Zhonghua Liu 《Journal of separation science》2013,36(18):3026-3034
SDS and sodium deoxycholate (SDC) as two representative detergents have been widely used in LC–MS/MS‐based shotgun analysis of membrane proteomes. However, some inherent disadvantages limit their applications such as interference with MS analysis or their weak ability to disrupt membranes. To address this, the combinative application of SDS and SDC was developed and evaluated in our study, which comprehensively used the strong ability of SDS to lyse membranes and solubilize hydrophobic membrane proteins, and the high efficiencies of an optimized acetone precipitation method and SDC in sample clean‐up, protein recovery, and redissolution and digestion of precipitated proteins. The comparative study using a rat‐liver‐membrane‐enriched sample showed that, compared with other three commonly used methods including the filter‐aided sample preparation strategy, the combinative method not only increased the identified number of total proteins, membrane proteins, and integral membrane proteins by an average of 19.8, 23.9, and 24.8%, respectively, but also led to the identification of the highest number of matching peptides. All these results demonstrate that the method yielded better recovery and reliability in the identification of the proteins especially highly hydrophobic integral membrane proteins than the other three methods, and thereby has more potential in shotgun membrane proteomics. 相似文献
45.
Zilong Tang Zhonghua Zhu Lin Yan Shuhong Chang Hanwen Liu 《Journal of heterocyclic chemistry》2013,50(5):1116-1120
A series of novel substituted 3,4‐dihydro‐2H‐1,3‐benzoxazines were prepared in moderate to good yields by aza‐acetalizations of aromatic aldehydes with 2‐(N‐substituted aminomethyl)phenols in the presence of chlorotrimethylsilane or SnCl4. It was found that chlorotrimethylsilane was more effective for the reaction, especially for the reaction of fluorobenzaldehyde, and thereby, an efficient method for the preparation of 3,4‐dihydro‐2H‐1,3‐benzoxazines was developed. The structures of the compounds were determined by FT‐IR, 1H NMR, 13C NMR, MS, and elemental analysis. 相似文献
46.
免疫亲和柱净化-液相色谱-串联质谱法同时测定猪肉中6种玉米赤霉醇类化合物残留量 总被引:1,自引:0,他引:1
建立了猪肉中6种玉米赤霉醇类化合物残留量的免疫亲和柱净化-液相色谱-串联质谱(IAC-LC-MS/MS)分析方法。酶解后的样品用乙醚提取,提取液浓缩后用三氯甲烷溶解,NaOH溶液反萃取,经免疫亲和柱富集和净化后,采用LC-MS/MS进行测定,外标法定量。在Shimadzu Shim-pack VP-ODS C18反相柱上分离,梯度洗脱,流动相为乙腈和2 mmol/L乙酸铵溶液;质谱采集为电喷雾负离子多反应监测模式。6种目标物的线性范围为0.5~200μg/L,相关系数(R)大于0.999,定量限(LOQ)在0.05~0.63μg/kg之间;添加浓度在1.0~5.0μg/kg范围内,方法回收率为71.3%~93.7%,相对标准偏差在3.7%~9.7%之间。该方法灵敏度高、重现性好,适用于猪肉样品中痕量玉米赤霉醇类药物残留的测定。 相似文献
47.
把纳米铜和石墨烯修饰在玻碳电极表面,制备了纳米铜/石墨烯复合修饰电极。采用电化学方法,在!1.5~0 V的循环扫描电位条件下,氧化石墨烯(GO)和Cu2+同时在玻碳电极上被电化学还原,形成石墨烯(Gr)和纳米铜(CuNPs)复合膜。所制备的修饰电极对葡萄糖等单糖化合物具有较高的电催化活性,且电极稳定性和重现性均良好。将此修饰电极作为电化学检测器,与高效阴离子交换色谱联用,分离测定了5种单糖化合物(岩藻糖、阿拉伯糖、半乳糖、葡萄糖和甘露糖)。结果表明,岩藻糖和阿拉伯糖的线性范围为0.1~100 mg/L,半乳糖、葡萄糖和甘露糖的线性范围为0.5~100 mg/L,5种单糖化合物的线性相关系数均大于0.998,相对标准偏差RSD(n=6)为1.9%~2.5%,检出限在0.02~0.10 mg/L之间;将此方法用于测定样品桑黄粗多糖的单糖组成,测得5种单糖的回收率为84.8%~94.5%,准确度和精密度均较好。 相似文献
48.
49.
Kefan Guo Yao Chen Zheng Zhou Shu Zhu Zhonghua Ni Nan Xiang 《Electrophoresis》2022,43(21-22):2184-2194
Current three-dimensional micromixers for continuous flow reactions and nanoparticle synthesis are complex in structure and difficult to fabricate. This paper investigates the design, fabrication, and characterization of a novel micromixer that uses a simple spatial Tesla valve design to achieve efficient mixing of multiple solutions. The flow characteristics and mixing efficiencies of our Tesla valve micromixer are investigated using a combination of numerical simulations and experiments. The results show that in a wide range of flow rates, viscoelastic solutions with different concentrations can be well mixed in our micromixer. Finally, experiments on the synthesis of chitosan nanoparticles are conducted to verify the practicability of our micromixer. Compared with nanoparticles prepared by conventional magnetic stirring, the size of nanoparticles prepared by micromixing is smaller and the distribution is more uniform. Therefore, our Tesla valve micromixer has significant advantages and implications for mixing chemical and biological reactions. 相似文献
50.
采用UωB97X-D/6-311+G**方法, 研究了气相、 甲苯和水中OH自由基(·OH)引发CH3SSCH3自由基阳离子(CH3SSC +, DMDS?+)裂解的反应机理, 并讨论了溶剂效应对反应的影响. 结果表明, ·OH和DMDS·+首先形成自由基耦合产物CH3S(OH)SCH3+(R1)和氢提取产物复合物[CH2=SSCH3+H2O]+(R2); 随后R1裂解直接发生 S—S键断裂协同质子转移, 而R2裂解依次发生构象变化、 C=S键亲碳加成和S—S键断裂协同质子转移. 去质子化的裂解产物为CH3SOH, CH2=S和HSCH2OH. 甲苯略微降低了裂解反应速控步骤的自由能垒. 水溶剂有利于R1裂解, 但不利于R2裂解, 尤其是单个水分子参与反应. 在气相、 甲苯和水中, 以·OH和DMDS·+为初始反应物, 虽然速控步骤的自由能垒为167.6~202.8 kJ/mol, 但裂解反应均是放热反应(?154.3~?31.4 kJ/mol). 相似文献