荧光检测-高效液相色谱法测定水果、蔬菜中抗蚜威残留量

建立了水果、蔬菜中抗蚜威残留的荧光检测-高效液相色谱法。样品以乙腈提取,固相萃取氨基小柱(LC-NH2)净化,Waterscarbamateanalysis(3.9mm×150mm,4μm),V(甲醇)∶V(水)∶V(乙腈)=16∶68∶16为流动相,柱温30℃,流速为1.5mL/min进行分离,用荧光检测器进行检测,激发波长和发射波长分别为317nm,392nm。回收率在98.5%~105.4%,相对标准偏差为3.0%~4.6%,检出限为0.01mg/kg。     

克菌丹和灭菌丹的气相和液相色谱分析方法

采用气相色谱法和高效液相色谱法两种方法分别对克菌丹和灭菌丹进行定性定量分析。气相色谱法均以邻苯二甲酸二戊酯为内标物,色谱柱采用3%OV-101 chromosorb AW DMCS 150~177μm,1 m×3 mm玻璃柱,柱温为195℃,汽化温和检测温均为230℃,克菌丹和灭菌丹的回收率分别为99.2%~100.7%和98.8%~99.9%;方法相对标准偏差分别为0.46%和0.59%。高效液相色谱法中使用Nova-PaK C18250 mm×4.6 mm色谱柱,以V(甲醇)∶V(水)=85∶15为流动相,检测波长为225 nm。克菌丹和灭菌丹的回收率分别为99.5%~100.6%和98.9%~99.7%;方法相对标准偏差分别为0.68%和0.51%。     

加速溶剂萃取-高效液相色谱法测定土壤中咪唑乙烟酸残留量

建立了加速溶剂萃取-高效液相色谱法测定土壤中咪唑乙烟酸除草剂残留量的检测方法.加标土壤样品以V(甲醇)∶V(冰乙酸)＝5∶1作提取剂,在温度50 ℃,压力9 MPa下静态萃取10 min,提取物用高效液相色谱二极管阵列检测器进行分析.色谱柱为ODS柱,流动相为V(甲醇)∶V(水)∶V(冰乙酸)＝50∶46∶4,流量: 1 mL/min;检测波长: 254 nm.结果表明: 1和10 μg/g的加标回收率分别为90%和86%,相对标准偏差分别为4.1%和4.5%,检出限可达0.006 μg/g.     

高效液相色谱法测定酿酒酵母中S-腺苷-L-蛋氨酸

利用高效液相色谱(HPLC)法对酿酒酵母(Saccharomyces Ceverisiae,SC)发酵样品中S-腺苷-L-蛋氨酸(SAM)的测定方法进行研究。流动相为甲醇∶40 mmoL/LNH4H2PO4-8 mmoL/L 1-庚烷磺酸钠=20∶80(V/V),流速为1.0 mL/min,检测波长为254 nm,用外标法进行定量。方法的相对标准偏差和平均回收率分别为0.82%和98.22%。该方法简便有效,适用于SAM系列产品生产中的质量控制。     

高效液相色谱法测定季戊四醇和二季戊四醇

建立了分离测定季戊四醇和二季戊四醇的反相高效液相色谱法。在C18烷基键合相分离柱上,以乙腈∶水[5∶95(V/V)]为流动相,流速为1.0ml·min-1。紫外检测波长为196nm,方法的相对标准偏差季戊四醇和二季戊四醇分别为2.4%和4.5%。加标回收率分别为96.36%和95.78%。方法用于二季戊四醇生产工艺条件的选择和反应液浓度的控制分析。     

高效液相色谱法测定高脂类酱腌菜中苯甲酸、山梨酸的含量

建立了高效液相色谱法测定高脂类酱腌菜中苯甲酸、山梨酸含量的测定方法.样品用乙醚高速匀浆的方法提取后,通过改变其酸碱度而改变其在有机相和水相中分配比的方法,去除脂肪等杂质的干扰,采用C18分离柱,用甲醇∶乙酸胺溶液(5∶95,V/V)作为流动相,检测波长为230 nm,同时测定苯甲酸、山梨酸.2种组分的检出限分别为为0.3 mg/kg0、.25 mg/kg,回收率在94.1%~105.0%之间,测定结果的相对标准偏差为1.3%~2.1%.     

高效液相色谱法测定九味石灰华散中羟基红花黄色素A和红景天苷的含量

建立了测定中药复方制剂九味石灰华散中羟基红花黄色素A和红景天苷含量的高效液相色谱方法.采用Kromasil C18色谱柱(5μm,250 mm×4.6 mm),以乙腈∶0.1%磷酸溶液(12∶88,V/V)为流动相,流速1.0 mL/min,羟基红花黄色素A的检测波长为403 nm,红景天苷的检测波长为275 nm.羟基红花黄色素A和红景天苷分别在0.288~180μg/mL和4.8~1 200μg/mL范围内呈良好的线性关系(r值为0.999 8~0.999 9),最低检出限分别为0.03μg/mL和0.5μg/mL(S/N=3),加标回收率分别为95.7%~97.4%和95.9%~98.6%.该方法简便、准确、重现性好,可用于九味石灰华散的质量控制.     

布洛芬注射液包材相容性研究中铅、镉、砷、锑的测定

建立中性硼硅玻璃包材加速试验后布洛芬注射液中铅、镉、砷、锑含量的检测方法。采用微波消解仪以硝酸分解样品,用石墨炉原子吸收光谱仪测定铅、镉含量,测定波长铅为283.3 nm,镉为228.8 nm,铅、镉分别在5.0~50.0,0.5~5.0μg/L范围内有良好的线性,相关系数分别为0.999 7,0.996 2,检出限分别为0.26,0.01μg/L,测定结果的相对标准偏差分别为1.06%,2.40%(n=6),加标回收率分别为100.2%~101.9%,97.1%~105.1%。用原子荧光光谱仪测定砷、锑含量,测定波长砷为193.7 nm,锑为217.6 nm,砷、锑在1~10μg/L范围内均有良好的线性,相关系数分别为0.999 9,0.999 5,检出限分别为0.03,0.01μg/L,测定结果的相对标准偏差分别为1.04%,2.65%(n=6),加标回收率分别为94.2%~96.5%,92.6%~96.5%。该测定方法快速,灵敏度高,适用于内包装材料加速试验后药品中重金属元素含量变化的研究。     

高效液相色谱法测定化妆品中防腐剂的研究

采用高效液相色谱法测定化妆品中山梨酸、苯甲酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯等6 种防腐剂,用Zorbax ODS柱(150×4.6 mm i.d.,5μm),磷酸二氢钾∶乙腈=90∶10(V/V)为流动相,加入磷酸调pH值为2.0,检测波长254 nm。样品用乙醇水冰乙酸(70∶29.5∶0.5,V/V)提取,回收率为90.8%~105.7%,相对标准偏差为3.1%~8.5%。     

发酵液中香兰素的反相高效液相色谱分析方法研究

建立了测定发酵液中香兰素含量的反相高效液相色谱方法。采用Symmetry C18柱(5μm,4.6 mm i.d.×150 mm),以V(甲醇)∶V(水)=35∶65为流动相,流速为1.0 mL/min,紫外检测波长为280 nm,柱温为室温,进样量10μL。香兰素在5.0~1000 mg/L范围内,峰面积与质量浓度呈良好的线性关系,相对标准偏差RSD为0.68%,回收率在99.88%~100.28%之间。该方法适用于微生物发酵法合成香兰素的质量控制及发酵工艺的改进。     

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%.     

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.     

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.     

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.     

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.     

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.     

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.     

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.