尿酸-铁氰化钾-鲁米诺化学发光测定亚硝酸盐

在酸性介质中，亚硝酸盐氧化亚铁氰化钾为铁氰化钾，利用尿酸-铁氰化钾-鲁米诺化学发光体系，建立了一种间接测定亚硝酸盐的新方法。讨论了酸度、反应物浓度、干扰离子等因素的影响。方法的检出限为0.05μg/L，对样品进行了平行测定（n=11），其相对标准偏差为1.8%-3.2%，线性范围为0.001-10ng/L。方法简便，易于操作，并具有较高的灵敏度和选择性。用于环境水样及食品中亚硝酸盐的测定，回收率为95.7%-105.8%，结果令人满意。     

人血清中镁钙铁铜锌的ICP-AES法同时测定

使用ICP－AES法同时测定了血清样品中的镁、钙、铁、铜、锌，加标回收率为95%-101%，11次测定的RSD（n=11）小于2.7%；方法操作方便，分析速度快，结果准确。     

毛细管气相色谱法快速测定西瓜及饮料中的甜蜜素

建立了毛细管气相色谱法测定西瓜和饮料中甜蜜素的方法.甜蜜素在0.1-10.0g/L范围内线性关系良好,相关系数R2= 0.999 2.以10倍信噪比计算,方法的定量限为0.5 mg/kg.两种果味饮料样品测定结果的相对标准偏差分别为0.87%,1.03%(n=6),西瓜样品的加标回收率为96.0%-103.8%,饮料样...     

密封恒温分光光度法快速测定化学需氧量

建立了密封恒温消解样品,测定化学需氧量（CDDcr)的分光光度法。应用正交试验法确定了密封恒温法消解试样的最佳条件,此方法有机物的氧化率为98.33%-99.50%。CODcr值在0-800mg/mL范围内符合比耳定律。样品测定的相对标准偏差为0.39%（n=12),加标回收率为97.50%-99.56%。用该法测得的CODcr值与标准回流法所得结果一致。     

原子荧光光谱法测定多金属矿标准样品中的砷、汞、铋

采取减少试样反应量及必要的分离手段，以原子荧光光谱法测定基体成分复杂、待测元素含量差异较大的多金属矿标标准样品中的砷、汞、铋，砷、汞、铋的检出限分别为0.2、0.01、1.3ng/mL，测定结果的相对标准偏差分别为1.88%-4.04%、2.1%-5.8%、1.1%-8.9%，线性相关系数均大于0.9970。标准样品的测定结果与推荐值基本吻合。该方法具有简单、快速、准确、精密度好等优点。     

高效液相色谱串联质谱法测定血清中内美通

研究了高效液相色谱串联质谱联用测定人血清中内美通的方法。用乙醚提取血清中的内美通,米非斯酮做内标,电喷雾离子化,选择内美勇母、子离子对m/z309-m/z241;内标的母、子离对对m/z430-m/z372;串联质谱采用多反应扫描监测方法,定量测定人血清的内美通。该方法测定速度快,灵敏度高,选择性好。方法的标准曲线线性范围3.5-177μg/L（r^2=-0.999);检出限0.8μg/L;进行6次平行测定,日间RSD=2.3%-13.7%,RD=4.8%-3.0%;日内RSD=5.5%-14.8%,RE=3.1%-6.7%;回收率内美通是91.0%,内标米非斯酮是90.6%。4min完成一个样品测定。     

流动注射在线萃取—火争原子吸收法测定食用盐中的锌

基于锌与1-（2-吡啶偶氮）-2-萘酚（简称PAN）形成的配合物可被氯仿萃取，从高盐基体样品中分离富集锌，利用自行设计的分相器，实验确定了最佳的流动注射在线萃取-火焰原子吸收光度法测定锌的流呼系统和化学反应条件。在选定的工作条件下，其RSD和检出限分别为4.3%（c=0.6μg/mL，n=11)和0.03μg/mL，测定速度为25样/h。用于实际样品的测定，加标回收率为97%-106%。     

ICP-AES测定废Al2O3基催化剂中Pt、Pd

研究了废Al2O3基催化剂中Pt,Pd的ICP－AES测定新方法。以王水溶解样品，在HCl(5 95)介质中，用工作曲线法对废Al2O3基催化剂中的Pt,Pd直接进行测定，不需进行基体匹配。方法的检出限分别为：Pt 0.1μg/mL，P 0.045μg／mL；样品的加标回收率为Pt 95.2%-105.5%,Pd 95.3%-100.6%;RSD(n=6)均＜9％。     

气相色谱/质谱法测定熏肉中的多环芳烃

建立了熏肉中多环芳烃的气相色谱/质谱(GC/MS)测定方法。样品经正己烷-丙酮(体积比为1∶1)超声波提取、氧化铝柱净化后,用GC/MS分离测定。优化了25种多环芳烃(PAHs)化合物的分离测定条件。结果 25种PAHs回收率范围为48.5%-106.5%;日内(n=7)相对标准偏差为3.75%-7.95%。方法具有灵敏度高、准确度好、能同时分离测定20余种多环芳烃化合物的优点,适合于熏肉中多环芳烃化合物的分析测定。     

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。     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.