极谱法测定人发中痕量铜的研究

研究了痕量铜与CNS-及TriTonX 30 5非离子表面活性剂形成多元配合物 ,用示波极谱分析法测定痕量铜的新方法 .新方法铜的析出限为 1× 10 -10 g/mL ,工作曲线线性响应浓度范围为 5× 10 -9～ 5× 10 -7g/mL ,回收率为 98%～ 10 3% .直接用于人发、血清等样品中痕量铜的测定 ,其结果与原子吸收分光光度法测定结果对照相吻合     

分娩时母血脐血铜、锌微量元素变化的研究

测定了健康正常分娩的产妇49例的母血，脐带血和正常未孕妇女50例的血清铜，锌含量，结果表明，分娩期母血清中铜，锌，铜/锌比值低于未际妇女，有显著差别，铜未见差别，母血清中铜与铜/锌比值均高于脐血清中值，有显著差别，母血清中锌明显低于及早血清中值并有显著差别，分娩期血清中铜，锌值与胎儿体重关系无显著差异；胎膜早破与非胎膜早破无妊娠合并症者血清中铜，锌未发现差别，提示妊娠母亲血清中微量元素锌，铜与胎儿的生长发育有关。     

316名健康儿童血清锌、铜正常参考值调查分析

用原子吸收法对淮阴市区幼儿园316名健康儿童,进行了血清锌、铜含量的测定,建立了正常参考值范围。儿童血清锌、铜正常含量分别为0.941±0.210μg/mL、1.276±0.225μg/mL。儿童血清锌、铜在男女之间无显著性差异(P>0.05)。     

血清铜、锌、硒与恶性淋巴瘤关系的研究

测定６８例恶性淋巴瘤患者血清铜、锌、硒及铜／锌比值水平,采用ｔ检验和非条件Ｌｏｇｉｓｔｉｃ回归因素分析方法对测定结果进行分析。结果表明恶性淋巴瘤患者血清铜、铜／锌比值升高,而血清锌及硒水平降低。血清铜和铜／锌比值升高与肿瘤的负荷状态及病期明显有关,提示血清铜和铜／锌比值的测定对监测恶性淋巴瘤患者的病情变化有一定价值,非条件Ｌｏｇｉｓｔｉｃ多因素分析表明,血清锌、硒可能是恶性淋巴瘤发病的保护因素;而     

PAN-乳化剂OP分光光度法连续测定血清中的锌和铜

血清中的微量锌和铜是生物化学和临床医学研究的重要元素。近年的研究发现,人类血清中铜锌含量有一定比值,此比值与人体代谢和病理变化密切相关,因而测定血清的铜锌比值比单独测定血清中铜或锌的含量更有实用价值。本文报告在pH 8.5～9.0缓冲溶液中,使Zn~(2+)、Cu~(2+)与PAN生成红色不溶性络合物,选乳化剂OP增溶,再利用两络合物对二乙基氨基二硫代甲酸钠(DDTC)的稳定性不同而连续测定血清中锌和铜。与报导的测定     

双波长系数补偿法同时测定铜铁

研究了以5-Br-PADAP为显色剂,双波长系数补偿法同时测定铜、铁.根据试验结果,选择铜测定波长对为542/570nm,铁测定波长对为560/512nm.对混合物中铜、铁测定,本法比相应的双波长法灵敏度高,铜提高87%,铁提高38%.铜线性范围为0.5～15.0μg/25ml,铁线性范围为0.5～15.0μg/25ml,应用于食品中铜、铁的测定,均得到较满意的结果.     

同位素稀释热电离质谱法测定人血清中痕量铜和锌

采用热电离同位素稀释质谱法(ID-TIMS)准确测定了欧盟标准物质与测量研究院(EC-JRC-IRMM)组织的国际测量评估计划IMEP-17人血清样品中的痕量铜和锌。由于锌和铜都是易受污染的元素,本工作建立了仅用少量硝酸消解的低流程本底和适于热电离质谱测量的生物基体血清中痕量铜和锌的样品前处理方法;采用适当比例的硅胶和磷酸作为电离增强剂,在热电离质谱(TIMS)测量时获得了较高强度且稳定的铜和锌离子束;血清中痕量铜和锌的测量结果可直接溯源到国际单位mole。2种人血清样品中铜和锌测量结果的不确定度(k=2)分别为0.94%、0.83%和0.49%,测量值被EC-JRC-IRMM采用作为该样品的标准值。     

FIA-双流通池同时测定血清中的锌和铜

本文以2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚(5-Br-PADAP)为显色剂,乳化剂OP为增溶剂,二乙基二硫代氨基甲酸钠(DDTC)为竞争络合剂,采用双流通池(一个流通池用来测定锌和铜络合物吸光度之和,另一个测定锌络合物吸光度),在一次进样中同时测定血清中锌和铜的含量。测定频率为45样/小时,测定铜和锌的线性范围分别为0.02~0.10μg/mL和0~0.12μg/mL。本法具有操作简单、快速、灵敏度高和易于推广等优点。     

气动雾化进样-微波等离子体炬原子发射光谱法测定催化剂中铜和钠

研究了用微波等离子体炬原子发射光谱法(MPT-AES)测定催化剂中铜和钠含量的方法. 考察了测定铜和钠的实验参数, 选择了测定的最佳条件, 并考察了共存离子的干扰情况. 催化剂使用压力溶弹处理, 并用标准加入法来消除基体干扰. 实验结果表明, 铜和钠的检出限分别为2.0、 4.2 μg/L, 方法的RSD均小于2.2%, 线性范围分别为0.01～12.0 mg/L和0.02～8.0 mg/L. 样品测定的RSD均小于2.9%, 加标回收率均在96.1%～102%之间.     

火焰原子吸收光谱法测定锡阳极泥中铜的含量

建立了火焰原子吸收光谱法测定锡阳极泥中铜元素的分析方法。对锡阳极泥样品,采用盐酸、硝酸、高氯酸分解,氢溴酸挥发除去锡和锑的溶样方式,火焰原子吸收光谱仪测定铜,测定范围为1%～5%,并考察了仪器条件、不同酸浓度、干扰元素对铜含量测定的影响。实验结果表明铜的检出限为0.013μg/mL,加标回收率为95.5%～104%,相对标准偏差为0.81%～2.1%,方法准确度高、精密度好,能够很好地满足锡阳极泥中铜元素的测定。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.