日本大学分析化学教育现状简介与借鉴

科学技术的飞速发展使分析化学发展到了分析科学阶段[ 1] 。大学( 理工学科) 的分析化学教育应适应这一需要进行适当的调整, 使原本有学科交叉性质的分析化学( 科学) 具有更丰富的内涵[ 2, 3] ; 世界范围内的分析化学教育改革正在进行[ 4~ 9] , 改变原有的老师/ 教0( Teaching)、学生/学0(Learning) 的传统教学模式, 使学生带着问题学习(PBL, Problem Based Learning ) 、带着课题实践( PBA, Project Based Approach) , 以提高他们的学习兴趣, 提供培养创新能 力的氛围; 同时利用多媒体等现代教学手段, 既能增加单位时间内的信息量, 也可使学生形象地了解在实际中不可能接触到的大型分析仪器的结构和工作原理。作者于1994 至1998 年在日本国立群马( Gunma) 大学大学院( 研究生院) 学习, 亲身感受到现今日本大学的分析化学教育状况, 并一直关注最近几年日本大学分析化学教学改革进程。现将日本理工类大学分析化学的教育现状简介如下, 同时探讨日本大学分析化学教育改革中值得参考借鉴的经验, 与读者共同思考我国大学分析化学教育改革的有效途径

基于电感耦合等离子体质谱的生物分析

生命过程的正常运行离不开神秘但精致的生物机制调控,她就像一架庞大且精准的机器控制着生命的孕育、生长和死亡。这极为精致的生物机制吸引了无数科学家去尝试揭开她的神秘面纱。所幸的是,伴随着科学家从生物学、物理学和化学等不同角度的不懈探索,她的芳容已可见一斑。在分子和细胞水平上,科学家们以生物遗传(基因组学等)和蛋白国家自然科学基金项目(21035006;21275120); 国家基础研究计划“973”项目(2014CB932004

Quantification of selenium-tagged proteins in human plasma using species-unspecific isotope dilution ICP-DRC-qMS coupled on-line with anion exchange chromatography

Inductively coupled plasma dynamic reaction cell-quadrupole mass spectrometry (ICP-DRC-qMS) coupled on-line with anion exchange chromatography (AEC) has been developed for the quantification of selenium-tagged proteins in human plasma. Methane was employed as a reaction gas in the dynamic reaction cell to achieve the determination of Se-80 free of spectroscopic interference from Ar-40(2)+ and (BrH+)-Br-79. Five selenium species including selenoprotein P (SelP), glutathione peroxidase (GPx), selenoalbumin (SeAlb), and two unknown selenospecies (U1 and U2) in a pooled plasma sample from five healthy people were separated using AEC, and the distribution of selenium in SelP, GPx, SeAlb, U1 and U2 (about 45.5%, 19.1%, 15.1%, 2.9% and 8.1%) was determined by ICP-DRC-qMS using species-unspecific isotope dilution (Se-80/Se-77). Based on the detection limit (DL) of selenium (0.54 ng mL(-1)), we estimated that the DLs for SelP and GPx were 0.59 pmol mL(-1) and 1.7 pmol mL(-1), respectively. Through the stoichiometry of the selenium atom in the selenium-tagged proteins, SelP (2.7 +/- 0.1 mu g mL(-1)) and GPx (5.4 +/- 0.2 mu g mL(-1)) were successfully quantified.National Natural Science Foundation of China [20535020, 20775062]; National 863 project [2006AA06Z404]; National Basic Research Program of China [2003CD415001

In vivo phytochelatins and Hg-phytochelatin complexes in Hg-stressed Brassica chinensis L.

In vivo phytochelatins (PCs) and their corresponding Hg-PC complexes were characterized using RPLC-ESI-MS/MS in the roots of Brassica chinensis L. under the stress of a mercury cysteine complex (HgCys(2)) and/or a mercury humic acid complex (Hg-HA). Results indicated that the presence of Cys and/or HA decreased the Hg uptake in both the roots and shoots of B. chinensis but increased the generation of PCs in the roots compared with those where only HgCl2 was in the culture solutions. A series of Hg-PC complexes were synthesized in vitro for predicting the possible Hg-PC formed in vivo in the HgCys(2) and/or Hg-HA stressed roots of B. chinensis. The discovery of in vivo oxidized PC2, PC3 and PC4 and their corresponding HgPC2, HgPC3, HgPC4 and Hg2PC4, which were confirmed by their specific isotope distribution, provided definite evidence for understanding the defense and accumulation mechanism of B. chinensis to Hg, in which the induced PCs play an important role not only in Hg detoxification through forming Hg-PC complexes but also for reducing the oxidative stress induced by Hg2+.National Natural Science Foundation of China [20535020, 20775062]; National 863 Hi-Tech Project [2006AA06Z404]; National Basic Research Program of China [2009CB416000

镧在菠菜叶绿体中的分布及其对光合作用的影响

在体研究了稀土元素镧(La)对菠菜叶绿体Hill反应活力、Mg2+-ATPase和Ca2+-ATPase活性的影响,并用电感耦合等离子体质谱(ICP-MS)测定了叶绿体各亚细胞器中La的含量.实验结果表明,低(15mg·L?1)、中(30mg·L?1)浓度的LaⅢ对菠菜叶绿体Hill反应活力、Mg2+-ATPase和Ca2+-ATPase活性有明显的促进作用,而高浓度时(60mg·L?1)则表现出显著的抑制作用;叶绿体中大部分La位于光系统Ⅱ(PSⅡ)中,占叶绿体中La总量的90%左右.利用排阻色谱-紫外/电感耦合等离子体质谱联用技术(SE-HPLC-UV/ICP-MS)对La在PSⅡ中的存在点位进行了研究,发现La在PSⅡ中有两种不同的结合点位:La不仅可以部分竞争取代PSⅡ中与叶绿素结合蛋白相结合的Mg,而且还可能竞争结合到PSⅡ中Ca和Mn的结合点位上来影响光合作用效率

Research progress of integrated membrane process on high-value development of fish processing by-products

集成膜工艺不仅可以发挥各种膜过程的优势,而且利用集成的协同作用,能够更高效地解决水产加工副产物高值化开发中的分离纯化难题,同时具有节能、低耗、清洁等优点。文章分析了集成膜工艺在水产加工副产物高值化开发中的典型应用,并探讨了实现集成膜工艺产业化应用的关键环节。Integrated membrane process,making use of both individual and synergic advantages of membrane operations,provided more effective separation solution for high-value development of fish processing by-products and had merits of energy saving,low consumption,clean production and so on.Reviewed the typical applications of integrated membrane process on high-value development of fish processing by-products,further discussed the key issues of achieving the industrial application of integrated membrane process.福建省海洋与渔业厅重点项目(闽海渔合同[2010]2-21号);厦门海洋研究开发院项目(K11102

Synergistic defensive mechanism of phytochelatins and antioxidative enzymes in Brassica chinensis L. against Cd stress

Brassica chinensis L. was chosen and exposed to different concentrations of Cd exposure to evaluate its Cd-accumulating capacity and its potential cellular defensive mechanisms. Cd accumulation in the shoots and roots of B. chinensis was up to 1348.3 +/- 461.8 and 3761.0 +/- 795.0 mg per killogram of dry weight, respectively, under 200 mu mol/L of Cd exposure. Increasing Cd accumulation in the plant was accompanied by rapid accumulation of phytochelatins (PCs), and the sequestration of Cd by PCs provided a primary cellular mechanism for Cd detoxification and tolerance of B. chinensis. Furthermore, malondialdehyde formation, hydrogen peroxide content and antioxidative enzyme activities such as superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase were observed in the shoots of Cd-stressed B. chinensis. Increasing enzyme activities in response to concentrations of 5 to 50 mu mol/L Cd showed an efficient defense against oxidative stress, suggesting that the antioxidative system was a secondary defensive mechanism. These resulted in reduced free Cd damage and enhanced Cd accumulation and tolerance. Glutathione plays a pivotal role in these two detoxification pathways. In general, these results suggested that PCs and the antioxidative system are synergistic in combatting Cd-induced oxidative stress and that they play important roles in Cd detoxification of B. chinensis, and also give a deep understanding of the natural defensive mechanisms in plants under heavy metal stress

Strategy for absolute quantification of proteins: CH3Hg+ labeling integrated molecular and elemental mass spectrometry

Currently, molecular mass spectrometry is preferred by many for relative quantification but is not appropriate for "absolute" quantification of proteins. In this article we demonstrate a proof of concept for the absolute quantitative analysis of proteins via CH3Hg+ labeling and integrated application of molecular and elemental mass spectrometry. The smallest size of CH3Hg+ among monoalkyl mercurials and the specific and covalent interaction with sulfhydryl (-SH) in proteins results in forming a simple complex of CH3Hg+:-SH 1:1 when all -SH are exposed, as confirmed by ESI-MS. Based on the known number of -SH per protein, the absolute protein concentration can be obtained via Hg determination using ICP-MS, in which CH3HgCl could be simply used as an external standard. When bovine pancreatic ribonuclease A, lysozyme and insulin, which have an increasing number of various disulfide linkages in their molecules, were taken as model proteins, their corresponding absolute detection limits (3 sigma) reached 0.6, 1.2 and 0.4 pmol, respectively. These characteristics may be expected to provide an alternative approach for absolute protein quantification, especially specific biomarker determination, in the near future

Vapour generation at a UV/TiO2 photocatalysis reaction device for determination and speciation of mercury by AFS and HPLC-AFS

In this study we report a method for direct vapor generation of mercury species on nano TiO2 under UV irradiation in the presence of a formic acid and sodium formate mixture as a hole scavenger. A novelly designed UV/TiO2 photocatalysis reaction device (UV/TiO2 PCRD) was used as an effective sample introduction unit and an interface for mercury species determination by atomic fluorescence spectrometry (AFS) and speciation by HPLC-AFS for the first time. The detection limits of 10, 20, 30 and 70 pg mL(-1) of mercury chloride, methylmercury chloride, ethylmercury chloride and phenylmercury chloride, respectively, were achieved by AFS using flow injection mode. Compared with the traditional KBH4/NaOH-HCl system, UV/TiO2 PCRD is a superior alternative for online vapor generation of Hg species

SEC-ICP-MS and ESI-MS/MS for analyzing in vitro and in vivo Cd-phytochelatin complexes in a Cd-hyperaccumulator Brassica chinensis

In this study, in vitro synthesized Cd-phytochelatin (PC) complexes and in vivo Cd -PC complexes in Cd-stressed Brassica chinensis, which has been identified as a Cd hyperaccumulator, were characterized using SEC-ICP-MS and ESI-MS/ MS. The PCs (n = 1 -5) obtained from Cd-stressed B. chinensis together with CdCl2 were used to synthesize the in vitro Cd -PC complexes, and the formation of CdGS(1-2), (CdGS)(2), Cd1-2PC2, Cd1-3PC3, Cd1-3PC4 and Cd1-3PC5 was observed. In addition, for the first time, in vivo CdPC3 and CdPC4 complexes, as well as Cd-free PCs (n = 2-5) and desGlu-PC3 were detected in the extracts of Cd-stressed B. chinensis and confirmed by means of their corresponding isotopic peak distribution and MS/ MS spectra. Nitrogen saturated ammonium bicarbonate buffer (pH 7.8), instead of Tris-HCl and phosphate buffer, was used as a suitable mobile phase in order to stabilize the Cd -PC complexes and e. ectively avoid possible oxidation of PC analogues during SEC fractionation. Results obtained in this study give definite evidence elucidating the important roles which PCs play in plant defensive mechanisms to Cd stress. SEC-ICP-MS and ESI-MS/ MS were demonstrated as powerful and promising techniques for screening and identifying the in vivo metallopeptides, with accurate isotopic distribution assignment, in metal toxicological studies