火焰原子吸收分光光度法测定饲料中的钙含量

采用硝酸锶作干扰制剂，不经分离，直接用火焰原子吸收分光光度法测定饲料中的钙含量。该方法的线性范围为0-7.0μg/ml。线性回归方程为A=37.5169C 1.1143，相关系数r=0.9998，相对标准偏差为0.59%-1.53%，回收率为98%-100.5%。该方法简便、快速。     

反相离子对高效液相色谱法测定硫酸软骨素

以四甲基氯化铵作为离子对试剂，采用乙腈-2.28mmol/L四甲基氯化铵水溶液（5:95)作为流动相，选用C18色谱柱分离硫酸软骨素和杂质，建立了测定硫酸软骨素含量的反相离子对高效液相色谱方法。该方法的线性范围为0.4-8.0μg，回收率为98.8%-100.3%，相对标准偏差为0.17%-0.53%。该方法的精密度和准确度较高。     

反相高效液相色谱法测定强化奶粉中β-胡萝卜素含量

采用碱皂化石油醚提取,Kromasil C18柱分离,以甲醇∶氯仿=75∶25等度淋洗,二极管阵列检测器检测,测定了强化奶粉中β-胡萝卜素含量.对最佳皂化用碱量、皂化时间、α、β-胡罗卜素及β-胡罗卜素异构体分离条件进行了探索.该方法回收率为91.6%~96.3%,其标准偏差、变异系数分别为1.64%及1.76%.方法简便、快速,精密度及准确度在允许范围内,适用于奶粉中β-胡罗卜素的测定.     

ICP-AES法测定锌阳极中的铝、镉、铁、铜、铅

通过分析高频功率、雾化压力、辅助气流量和泵速等试验条件，建立了ICP-AES法测定锌阳极中铝、镉、铁、铜、铅的方法。用该方法测定锌阳极中的铝、镉、铁、铜、铅，其RSD分别为0.17%、0.63%、2.7%、5.2%、2.5%，回收率分别为99.3%-101.2%，99.3%-100.3%、97.1%-102.2%、97.8%-102.9%。对锌阳极试样进行测定，该方法的测定结果与GB4951-85方法的测定结果基本一致。     

络合滴定法快速测定重晶石中的钡

采用沉淀、给 合滴定法，间接快速地测定了重晶石中钡的含量。对重晶石熔样方式、络合反应条件及共存干扰离子的消除方法进行了研究。该方法快速、准确，加收率为98.5%-100.7%，RSD小于2.48%。     

IC5000型离子色谱仪在水环境监测中的应用

利用IC5000型离子色谱仪建立了水环境中F^-、Cl^-、NO3^-－N和SO4^2-的定量分析方法，相对标准偏差为0.54%-3.63%，回收率为97.2%-104.1%。对该仪器使用中常见的问题及解决方法作了论述。     

火焰原子吸收分光光度法测定复合肥料中的钾含量

以K404.4nm作为分析线，研究了火焰原子吸收分光光度法测定复合肥料中钾含量的方法。该方法的线性范围为0－208mg/L，线性回归方程为A＝0.0026c-0.0100，相关系数r=0.9992，RSD为2.4%-5.0%，回收率为95.6%-101.3%。该方法的测定结果与四苯硼酸钾重量法基本一致，且方法简便、快速。     

高效液相色谱法检测南极磷虾油中总虾青素含量

建立了一种检测南极磷虾油中总虾青素含量的高效液相色谱方法。样品采用Na OH-甲醇溶液皂化后加入Na HSO4终止反应,反应液经正己烷液液萃取净化,采用C18液相色谱柱分离,二极管阵列检测器在476 nm波长进行测定,虾青素在5 min内得到较好分析。考察了皂化时间对虾青素酯皂化效率的影响,研究结果显示,皂化30 min为最佳反应时间。虾青素含量在0.2~20.0 mg/L范围内与其峰面积呈良好的线性关系,相关系数为0.999 9,检出限为0.005 mg/kg,定量下限为0.2 mg/kg。日内精密度(RSD)≤3.4%,日间RSD≤4.3%,南极磷虾油样品的加标回收率为90.2%~95.2%。该方法的线性范围宽、准确性好、精密度高,样品前处理方法简便,适用于南极磷虾油中总虾青素含量的分析检测。     

电感耦合等离子体质谱测定中草药中痕量稀土元素的研究

本文报道了微波消解／ICP－MS测定中草药中痕量稀土元素的新方法。在优化实验条件下，方法的检出限为0.71-15.2pg/mL，相对标准偏差为0.80%-3.3%，加标回收率为87.4%-106%。该法具有操作简便、快速、灵敏度高、准确度好和多元素同时测定等优点。     

离子色谱法测定大气硫酸盐化速率方法的改进

用离子色谱法测定大气硫酸盐化速率时，采用淋洗液常温浸泡过夜制备样品溶液，回收率为96.7%-102.0%，该样品溶液制备法使离子色谱法测定大气硫酸盐化速率简单、易行。     

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.     

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.     

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.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

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.