偏最小二乘法-BP 神经网络用于多组分药物测定

先将输入向量采用偏最小二乘法进行成分分析,再与ＢＰ神经网络法相结合,用于测定甲硝唑,头孢唑啉钠,维生素Ｂ６三给分。三给分的平均回收率及ＲＳＤ分别为９９．３％,０．７１％;９９．１％,０．９３％;９９．３％,２．８％。     

利用微波消解和高效液相色谱荧光检测法测定环境水样中痕量硒

基于微波消解和正相液相色谱－荧光检测测硒法,实现了对环境水样中亚纳克级硒的测定。考察了ＨＮＯ３和Ｈ２ＳＯ４－Ｈ２Ｏ２两种消化体系及其工作条件,方法检出限分别可达 ７．２和 １０．４ ｐｇ Ｓｅ,对标准参考物质的回收率分别为９９．４±２．０和９７．８±２．５％,在０～１．５ｎｇＳｅ范围内有线性关系（Ｒ２＜０．９９６）。对北京地区 ４种不同类型水体水样含硒量进行了分析测定（２ｍＬ样品）,其浓度范围为 ０．２０～０．９０μｇ／Ｌ,标准加入回收率为９９．１％～１０３．４％。     

自模式分辨红外光谱法在VC,VB2不分离测定中的应用

本文研究了自模式曲线分辨红外光谱法在维生素Ｃ－Ｂ２混合物体系中的应用，合理地估计了背景吸收。测定了不同配比维生素Ｃ－Ｂ２混合物组分，平均回收率分别为维生素Ｃ１０１．７±４．４％、维生素Ｂ２９９．４±３．５％，优于Ｂｅｃｋｍａｎ公司的标准曲线法：维生素Ｃ９３．０±２１．１％、维生素Ｂ２１０４．３±１５．２％。     

液相色谱法测定生物发酵液中水溶性维生素的研究

本文采用反相离子对色谱测定了生物发酵液中的七种水溶性维生素。提出了用自行装填的酸性氧化铝（０．１９～０．１５ｍｍ）前置柱，和５％乙酸洗脱样品的前处理方法；并就有关的色谱条件进行了选择。色谱柱为ＮｏｖａＰａｋＣ１８；流动相Ａ液为０．０５ｍｏｌ／Ｌ庚烷磺酸盐（ＰＩＣＢ７），冰乙酸调ｐＨ＝２．５；Ｂ液为甲醇＋三乙胺（１００＋０．５）；梯度洗脱；ＵＶ２５４ｎｍ、２９０ｎｍ、３６０ｎｍ同时测定。线性范围为０．１～１０μｇ，各种维生素的ＲＳＤ在１．２％～３．０％之间（ＶｉｔａｍｉｎＢ１２除外），回收率大于９０％。     

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。     

花生中黄曲霉毒素B1、B2、G1、G2的多功能净化柱-高效薄层色谱分析

建立了一种测定食品中黄曲霉毒素（ ＡＦＴ） Ｂ１ 、Ｂ２ 、Ｇ１ 、Ｇ２ 的多功能净化柱（ ＭＦＣ） 净化, 单相展开的薄层色谱法。 以乙腈－ 水（ 体积比９ ∶１） 提取样品中ＡＦＴ, 经ＭＦＣ 净化浓缩后, 采用ＨＳＧ６０ 薄层板, 以丙酮－ 氯仿（ 体积比９ ∶１） 展开, 薄层扫描仪荧光检测扫描定量。该法用于花生样品的检测,４ 种毒素的分离良好; 线性范围：０ ．０５ ～１ ．０ ｎｇ, 相关系数≥０ ．９９９ １; 检出限均达到０ ．５ ×１０ － ９ ; 相对标准偏差为４ ．６７ ％ ～１０ ．２１ ％ ; 样品加标０．５ ×１０ － ９ ～１０ ×１０ － ９ , 平均回收率为８６ ．５ ％ ～９９ ．０％ 。     

抑制-褪色光度法测定维生素C

基于维生素Ｃ对罗丹明Ｂ和Ｋ２Ｓ２Ｏ８间经Ａｇ＋催化的褪色反应的抑制作用,提出了一种测定痕量维生素Ｃ的新的褪色光度法。维生素Ｃ浓度在０～１．２０ｍｇ／Ｌ范围内服从比耳定律,检出限 ２．０ ×１０－１０ｇ／ｍＬ。该法用于蔬菜样中维生素Ｃ的测定结果满意,其测定结果与碘量法的测定结果相同。     

荧光光度法直接测定环境水中苯酚和十二烷基苯磺酸钠的含量

本文研究了用荧光分光光度法直接测定环境水中苯酚和十二烷基苯磺酸钠（ＳＤＢＳ）二种水中污染物。在ｐＨ〉１１直接测定ＳＤＢＳ含量，波长为λｅｘ／λｅｍ＝２３０／２９５ｎｍ，检出限４．４ｎｇ／ｍＬ，线性范围０￣２．２μｇ／ｍｌ。在ｐＨ＝６，波长为λｅｘ／λｅｍ＝２３０／２９５ｎｍ，测得二者合量，从合量中减去ＳＤＢＳ含量即得苯酚含量，检出限４．０ｎｇ／ｍｌ，线性范围０￣０．８５μｇ／ｍＬ，回收率达９９％￣     

钴－5－（4－硝基苯偶氮）－8－（4－甲苯磺酰氨基）－喹啉配合物的极谱波研究

钴（Ⅱ）在ＨＡｃ－ＮａＮＯ＿２－吐温－８０－ＮＰＴＳＱ体系中有一灵敏的阴极极化导数波，其峰电位－１．００Ｖ（ｖｓ．ＳＣＥ），钴浓度在４．０×１０￣（－９）～３．０×１０￣（－７）ｇ／ｍＬ范围内与峰电流有良好的线性关系。本文讨论了测定钴（Ⅱ）的最佳实验条件，对极谱波的性质进行了初步探讨，并作了维生素Ｂ＿（１２）中钴的测定，测定结果的相对标准偏差为３．７４％，回收率为９６～１０８％。     

感耦等离子体质谱法测定高纯氧化镥中14个痕量稀土杂质

本文报道了用感耦等离子体质谱法（ＩＣＰ－ＭＳ）测定高纯氧化镥中１４个稀土杂质的方法。镥基体对测定元素无谱线干扰，但对测定信号产生显著抑制作用。加入内标后有效地补偿了这种基体抑制效应，方法检出限为０．００５～０．０３ｎｇ／ｍＬ。样品加标为０．０１μｇ时，回收率为９０％～１０３％。精密度（ＲＳＤ）为１．４％～４．２％。方法简单，不需分离富集，样品消耗量少（１０ｍｇ）。１４个稀土元素的总测定下限（１０）可达０．５８μｇ／ｇ可直接测定纯度为９９．９％～９９．９９９９％的氧化镥中稀土杂质。     

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.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.