气相色谱法测定新型多元复合液肥中二羧酸

 建立了新型多元复合液肥中丁二酸、戊二酸、己二酸的气相色谱分析方法。色谱条件：５％ＳＥ－３０不锈钢填充柱,程序升温,内标物为丙二酸二乙酯,３种二元酸二乙酯分别在２．３～９．３μｇ,１０．８～４３．２μｇ和２．８～１１．０μｇ质量范围内,其样品质量与样品峰面积和内标峰面积之比呈良好的线性关系,相关系数ｒ≥０．９９５５。     

不经分离,高敏,连续光度滴定混合物中钕和铁

提出以Ｆｅ（３＋）（Ｎｄ（３＋）－ＣＡＳ－ＣＰＢ－Ｃ２Ｈ５ＯＨ作为不经分离、高敏、连续光度配合滴定混合物中Ｆｅ（３＋）和Ｎｄ（３＋）的多元胶束配合指示体系。滴定Ｆｅ（３＋）和Ｎｄ（３＋）的适宜ｐＨ分别为２．３～３．２和６．０～８．６。用ＥＤＴＡ目视滴定Ｆｅ（３＋）时，终点处由蓝紫变粉红色，对比度大（Δλ＝１３０ｎｍ）、灵敏度高（配合物摩尔吸光系数ε（６３０）＝１．１４×１０５Ｌ·ｃｍ（－１）·ｍｏｌ（－１），至少可检测０．４μｇ／ｍＬ，滴定线性范围为０～２．８μｇ／ｍＬ。线性相关系数为０．９９９４；目视滴定Ｎｄ（３＋）时，终点处由绿色变橙黄，Δλ＞１８０ｎｍ，ε（６３０）＝７．６×１０４，至少可检测１μｇ／ｍＬ，滴定线性范围０～３．７μｇ／ｍＬ，线性相关系数０．９９９４。对于铁钕硼混合物样品则不经分离在６３０ｎｍ处连续光度滴定，可更精密、高敏、准确地确定终点，变异系数１．７６％～２．８６％，标准加入回收率９６％～１０４％，且简便、快速。     

萘普生及其酯类的手性分离和光学纯度测定

以磺化β－ 环糊精作为手性分离添加剂, 分别对萘普生、萘普生甲酯和萘普生氯乙酯进行了毛细管电泳手性分离研究, 当以含４０ ｇ／Ｌ 的磺化β－ 环糊精的０ ．０１０ ｍｏｌ／Ｌ 的三羟甲基氨基甲烷－ 柠檬酸为缓冲液（ｐＨ５．０） 时,上述３ 种化合物的手性分离度分别为２ ．１９ 、２ ．６０ 和１ ．９９ 。 手性化合物的出峰时间和校正峰面积的相对标准偏差分别为２ ．８４ ％ 和６ ．２６％ , 而两对映体的相对出峰时间和相对校正峰面积的相对标准偏差分别为０ ．５２ ％和１ ．８６ ％ 。 对萘普生和萘普生氯乙酯的实际样品进行了光学纯度测定, 测定结果与ＨＰＬＣ 进行了比较。     

单扫示波极谱法测定茶叶中铜

在ＰＨ６．８磷酸盐缓冲体系中，Ｃｕ（Ⅱ）－乙酰丙酮产生一灵敏的极谱波，峰电位为－０．２５Ｖ，检出下限为０．０００６４μｇ．ｇ＾－１，线性范围为０．００１３－３．２μｇ．ｇ＾－１，用单扫示波极谱法测定茶叶中铜，具有灵敏、准确、快速、简便、选择性好的特点。     

2，3－二氨基萘荧光分光光度法测定环境水样中的痕量亚硝酸盐

本文描述了用２，３－二氨基萘荧光分光光度法测定水样中亚硝酸盐的最佳测定条件，并测定了井水和湖水中的亚硝酸盐。测定样品的检出限为０．４μｇ／Ｌ，线性范围是１．０～１５００μｇ／Ｌ，相对标准偏差为１．６％，加标回收率为９５％～１０６％。本法简便、快速，准确度高，共存离子干扰小，样品无须萃取步骤。     

固体石蜡作粘合剂的纯碳糊电极的电化学活化及其应用于色氨酸的测定

研究了以固体石蜡作粘合剂的纯碳糊电极的电化学活主用于色氨酸直接测定的方法。活化后的电极对色氨酸的吸附能力大大增加，在ＨＡｃ－ＮａＣ溶液中，于＋０．３Ｖ富集后，于＝１．０１Ｖ出峰，用线扫伏安法测定时，二次微分溶电流，与色氨酸浓度在８－１０μｇ／Ｌ范围内成线性；检测限可达２μｇ／Ｌ；２倍的酪氨酸和其它氨基酸不干扰，用于氨基酸酸芭物样品和合成血清样品中色氨酸的测定，相对标准偏差小于２％。     

催化极谱测定痕量铬的研究

本文研究了含氨介质中铬（Ⅲ，Ⅵ）－α，α－联吡啶－亚硝酸钠体系的电化学行为。建立了测定痕量铬的方法。测定铬的范围为０．００４－０．０２８μｇ／ｍＬ和０．０４－０．２８μｇ／ｍＬ，检测下限为２．０×１０＾－＾３μｇ／ｍＬ，用以测定生物样品中痕量铬，变异系数为９．８％。     

染毒粮食中7种化学战剂的气相色谱分析方法

为了研究染毒粮食（大米、面粉）中７种化学战剂的检测方法,建立了相应的气相色谱分析方法。该法采用火焰光度检测器检测,ＢＰ－１０毛细管色谱柱分离,二氯甲烷萃取。模拟染毒大米、面粉中化学战剂测定相对误差为２．０％～１２．０％、８．１０％～２７．３％。相对标准偏差分别为０．９％～６．１０％、３．９５％～１６．８％。方法的最低检出浓度为０．０１～２μｇ／ｇ。所建方法操作简便,灵敏度高。     

用新试剂2-[(5’-氟-2’-砷酸基苯)偶氮]-1,8-二羟基-3,6-萘二磺酸荧光法测定硼

研究了试剂２－［（５’－氟２’－砷酸基苯）偶氮］－１，８－二羟基－３，６－萘二磺酸与硼的荧光性能．硼与试剂形成１：２的强荧光配合物，其λｅｘ／λｅｍ＝２３４ ｎｍ／３８０ ｎｍ， Ｂ（Ⅱ）含量在 ０～３６０μｇ／Ｌ范围内呈良好线性关系，检测限为２．０６μｇ／Ｌ，据此建立了测定微量硼的新方法。该方法应用于茶叶、铝合金及粮食等样品中微量硼的测定，结果满意．     

ICP-MS 法测定高纯氧化铕中稀土杂质的研究

深入考察了ＩＣＰ－ＭＳ法测定高纯氧化铕时基体对稀土杂质测定的影响,研究了Ｐ５０７萃淋树脂分离大量基体Ｅｕ２Ｏ３的实验条件,建立了采用内标补偿直接测定大部分稀土杂质和经Ｐ５０７萃淋树脂分离基体后测定被干扰离子Ｔｍ相结合的高纯Ｅｕ２Ｏ３中稀土杂质的ＩＣＰ－ＭＳ分析方法。方法检出限为０．００５～０．０２１μｇ／Ｌ,加标回收率为８４％～１１２％。ＲＳＤ为１．４％～８．１％。本法适用于质量分数为９９．９９％～９９．９９９９％的高纯Ｅｕ２Ｏ３中稀土杂质的分析。     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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%).     

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.     

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.