多功能柱净化-高效液相色谱法检测谷物中的玉米赤霉烯酮

建立了玉米和小麦中玉米赤霉烯酮（ZEN）的多功能柱净化-高效液相色谱检测方法。样品经乙腈-水混合溶剂（V（乙腈）：V（水）=84：16）提取，通过多功能净化柱（MFC）进行一次性净化，以Symmetry^R C18柱为分离柱，甲醇-水（V（甲醇）：V（水）=68：32）为流动相进行高效液相色谱分离和检测。玉米赤霉烯酮的质量浓度在0．01～4．0μg／mL范围内呈良好线性，相关系数为0．9996。检出限为0．04μg／g，在0、04—5．0mg／kg添加范围内的回收率为87．5％～98．6％，相对标准偏差为1．5％～8．3％。     

土壤中多种有机氯及拟除虫菊酯类农药的GC-ECD测定

气相色谱法同时测定土壤中多种有机氯及拟除虫菊酯类农药。对土壤的分析结果：有机氯农药的检出限0．001～0、003μg／mL，拟除虫菊酯类农药检出限0.008～0．02μg／mL，线性相关系数0．9978～0．9999。用y（石油醚）：V（丙酮）=3：1超声波提取，有机氯农药回收率94．2％～124．0％，相对标准偏差为3．3％～8．8％（n=5）；拟除虫菊酯类农药回收率95．2％～118．3％，相对标准偏差为5．7％～7．1％（n=5）；方法适用于土壤样品中农药残留测定。     

三岛柴胡种子中的柴胡皂甙(英文)

利用溶剂萃取、正相硅胶柱层析及RP -8硅胶柱层析 ,从伞形科柴胡属植物三岛柴胡的种子中分离出三种柴胡皂甙 ,即 :柴胡皂甙c ,柴胡皂甙d ,6″-乙酰基柴胡皂甙d。它们的结构通过IR、UV、MS、1HNMR、13CNMR等现代波谱技术以及与标准样品对照确定。     

离子色谱法测定土壤中植物激素乙烯利

土壤样品中的乙烯利在IonPac AS14分离柱（4mm），（3．5mmol Na2CO3＋1．0mmol NaHCO3）／L淋洗液的淋洗条件下得到较好的分离。在0～10μg／mL的范围内标准曲线呈线性，检出限为（0．08μg／mL）。精密度好，10．266μg／mL时，保留时间的RSD=0．86％；峰高的RSD=1．1％；峰面积的RSD=1．0％。在此条件下，其它阴离子对乙烯利的检测不干扰，样品的加标回收率为85．6％～87．9％。     

非水体系毛细管电泳-紫外检测法测定苯甲酸和苯甲醛

建立了用非水相体系高效毛细管电泳-紫外检测法同时测定苯甲酸和苯甲醛的新方法，考察了运行电压、非水相介质和电解质等因素的影响，在25℃下，以V（乙腈）：V（碳酸丙烯酯）=1：1的混合液为溶剂，缓冲体系中含15mmol／L十六烷基三甲基溴化铵体积分数1％乙酸，重力进样30S，运行电压20kV，毛细管总长45cm有效长度30cm，φ75μm，检测波长285nm。苯甲酸线性范围为5～40μg／mL，线性方程为：Y=13．473ρ＋13．336，相关系数r=0．9985，检出限为0．92μg／mL，RSD为3．8％。苯甲醛的线性范围75～1125μg／mL线性方程为：Y=5．2449ρ＋564．01，相关系数r=0．9997，检出限为15．60μg／mL，RSD为3．5％。已用于经空气氧化后的苯甲醛中苯甲酸和苯甲醛的测定。     

使用限进介质色谱柱的柱切换高效液相色谱法直接进样测定大鼠血浆中舒必利

提出一种直接进样测定大鼠血浆中舒必利浓度的高效液相色谱方法,使用限进介质色谱柱作为预柱在线去除血浆蛋白后,将舒必利通过柱切换转移到分析柱中进行分析。限进介质色谱柱为CAPCELLPAKMFSCX阳离子交换柱（20×4．0mmi．d．,5μm）,分析柱为Kromasil C18柱（150×4．6mm i．d．,5μm）,限进介质柱预分离时流动相为PH=6．88的50mmol／L磷酸盐缓冲液乙腈（100：5,V／V）,切换后分析流动相为PH=6．83的50mmol／L磷酸盐缓冲液-乙腈（100：10,V／V）。流速均为1mL／min,检测波长为240nm。该方法检出限为17ng／mL,定量限为50ng／mL。舒必利在50～1400ng／mL之间线性良好（r=0．9997）,高中低浓度的日内、日间相对标准偏差分别为1．5％～4．2％及2．0％～5．2％,方法回收率为98．8％～104．1％．     

高效液相色谱法同时测定快安抗感冒液中5种组分的含量

采用高效液相色谱法（HPLC）同时测定快安抗感冒液中对乙酰氨基酚、咖啡因、盐酸甲基麻黄碱、马来酸氯苯那敏和愈创木酚甘油醚的含量。色谱柱为NOVA－PAKC_18柱,流动相为V（已腈）：V（0．03mol／L磷酸氢二铵）：V（0．004mol／L庚烷磺酸钠）：V（三乙胺）=12：44：43．5：0．5,并用磷酸调节pH值至3．0;检测波长220nm,柱温35℃。在此色谱条件下,各组分均获得良好分离。平均回收率为98．0％～100．3％,相对标准偏差小于1．8％。     

硫脲树脂富集-电感耦合等离子体质谱法测定地质样品中的超痕量金、银、铂、钯

研究了硫脲树脂富集，ICP-MS同时测定地质样品中超痕量金、银、铂、钯的方法。确定了仪器的最佳条件，并从吸附酸度、时间、树脂用量、解脱条件、干扰情况等方面进行了详细的考察。方法的检出限（3a）分别为Au：0．1lng／mL；Ag：0．35ng／mL；Pt：0．095ng／mL；Pd：0．08ng／mL。方法的RSD为（n=12）Au4．1％、Ag2．1％、Pt3．1％、Pd3．8％。测定了国家一级地球化学标准物质中的痕量Au、Ag、Pt、Pd，结果与标准值相吻合。     

气相色谱法测定柴胡注射液中环己醇

建立了气相色谱法测定柴胡注射液中环己醇的定量分析方法，以正己烷为萃取剂，水蒸汽蒸馏浓缩富集提取液，用PEG－20M柱，氢火焰检测器（FID）检测。结果表明，柴胡注射液中环己醇质量浓度在10.0μg/mL-120.0μg/mL范围内呈良好的线性关系（r=0.998），回收率为92 .3%-95.1%，RSD为1.1%－1.2%。     

高效液相色谱法同时测定快安抗感冒液中5种组分的含量

 采用高效液相色谱法（HPLC）同时测定快安抗感冒液中对乙酰氨基酚、咖啡因、盐酸甲基麻黄碱、马来酸氯苯那敏和愈创木酚甘油醚的含量。色谱柱为NOVA－PAKC_18柱,流动相为V（已腈）：V（0．03mol／L磷酸氢二铵）：V（0．004mol／L庚烷磺酸钠）：V（三乙胺）=12：44：43．5：0．5,并用磷酸调节pH值至3．0;检测波长220nm,柱温35℃。在此色谱条件下,各组分均获得良好分离。平均回收率为98．0％～100．3％,相对标准偏差小于1．8％。     

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.     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.