反相高效液相色谱法测定长柄扁桃仁产品中苦杏仁苷含量

本文采用反相高效液相色谱建立了长柄扁桃仁系列产品中苦杏仁苷含量的测定方法。长柄扁桃仁系列产品中的苦杏仁苷经甲醇提取,以V(甲醇)∶V(水)∶V(乙腈)=2∶85∶13为流动相进行洗脱,在220nm检测波长下,测得长柄扁桃仁中苦杏仁苷的平均质量分数为1.44%。方法线性范围为50～300μg/mL,线性相关系数r=0.9996,检出限为1.2μg/mL,平均回收率为98.97%(n=5)。     

高效液相色谱法同时测定扁桃仁中的水溶性维生素C,B1,B2和B6

建立了用高效液相色谱同时测定扁桃仁中4种水溶性维生素C,B1,B2和B6的方法。以酸水解法处理样品,在Inertsil ODS-3柱(25 cm×4.6 mm i.d., 5.0 μm)上,以0.05 mol/L KH2PO4 (pH 6.0)-甲醇(体积比为70∶30)为流动相进行等度洗脱,检测波长265 nm条件下,对陕西蒲城扁桃仁中的水溶性维生素C,B1,B2和B6的含量进行了同时测定。4种水溶性维生素在其质量浓度为5.0~50 mg/L时线性良好(r=0.9990~0.9997);添加水平为5.0~20.0 mg/kg时,平均回收率为91.77%～99.30%,相对标准偏差(n=3)为0.31%～1.98%。测得陕西蒲城产扁桃仁中维生素B2的含量为4.27～4.53 mg/kg,维生素B1的含量为0.799～0.838 mg/kg,未检出维生素C和维生素B6。该法简便、快速,准确性和重现性均较好,对果仁中水溶性维生素的测定具有一定的参考价值。     

HPLC测定藏药香菊活血丸中士的宁的含量

采用RP-HPLC法,色谱柱:Symmetry C18 (5 μm,4.6 mm×250 mm);流动相:V(甲醇)∶V(0.025 mol/L KH2PO4 (pH 2.8))=20∶80;检测波长260 nm;流速:0.7 mL/min,进样量10 μL,对香菊活血丸中士的宁进行含量测定.结果显示士的宁在0.004～0.128 μg (r=0.9993)范围内有良好的线性关系;平均回收率为101.73% (平均RSD=1.153%).本方法可用于香菊活血丸中士的宁的质量控制.     

高效液相色谱法测定人血浆中奥氮平的浓度

 用高效液相色谱法测定了人血浆中奥氮平的浓度。色谱条件 :采用岛津LC 6A型高效液相色谱仪 ;色谱柱为ZorbaxODS (15 0mm× 4 6mmi d ,粒径 5 μm) ;流动相为V(5 0mmol/L磷酸钠缓冲液 ,pH 7 2 )∶V(甲醇 )∶V(乙腈 ) =12∶10∶3的溶液 ;检测波长为 2 70nm ;流速为 1 0mL/min ;柱温 40℃ ;灵敏度 0 0 0 5AUFS ;纸速 2mm/min。实验结果显示 ,在上述条件下 ,该方法的线性范围为 15 μg/L～ 12 0 0 μg/L(r =0 9988) ,最低检测限为 3μg/L ,血浆中奥氮平的平均回收率为 (97 0 2± 3 11) % ,测定结果的日内平均相对偏差为 3 86 % (n =15 ) 。     

Determination of the Content of Gallic Acid in Huai Chrysanthemum by HPLC

为建立HPLC法测定怀菊花中没食子酸含量测定方法,采用Agilent C18柱(150 mm ×4.6mm,5μm),以V(甲醇)+V(超纯水+0.1％磷酸)=25 +75为流动相,流量:0.5 mL· min-1;柱温为25℃,检测波长:258 nm;进样量:10 μL,进行测定.结果表明,回归方程为y=3.054 2x-2.207 1,r2=0.999 1(n=6),线性范围0～20 μg,平均回收率97.28％,RSD为3.39％.样品中没食子酸质量分数为3.17 mg/g.方法快速、简便、准确、重现性较好,结果可靠,可为怀菊花中没食子酸的质量评价提供依据.     

反相高效液相色谱法同时测定柿叶中齐墩果酸和熊果酸

建立反相高效液相色谱法同时测定柿(Diospyros koki Linn.f.)叶中齐墩果酸和熊果酸的含量.采用Kromasil C18色谱柱(4.6 mm×250 mm,5 μm);流动相:V(甲醇):V(0.2%磷酸水溶液)=87:13;流速:0.8 mL/min;检测波长:210nm;柱温:30℃.齐墩果酸进样量在0.0848～1.696 μg范围内线性关系良好,r=0.9996,平均加样回收率为101.3%;熊果酸进样量在0.1408～2.816 μg范围内线性关系良好,r=0.9995,平均加样回收率为99.0%.3批样品测定结果表明,本法可作为柿叶中齐墩果酸和熊果酸含量测定的方法.     

反相高效液相色谱法测定人尿中利凡诺

建立了运用反相高效液相色谱法测定人尿中利凡诺的方法.采用Spherisorb C18色谱柱(250 mm×4.6 mm i.d.,5 μm);流动相: V(甲醇)∶V(乙腈)∶V(0.2 mol/L NH4Ac)=60∶37∶3;流速: 1.0 mL/min;柱温: 40 ℃;荧光检测器: 激发波长360 nm,发射波长500 nm.在5 ng/mL～1 μg/mL质量浓度范围内,呈现良好线性(r=0.9999),检出限为1 ng/mL.     

高效液相色谱法测定贝类中的软骨藻酸

 介绍了用反相高效液相色谱 (RP HPLC)测定贝类中软骨藻酸的方法。样品以V(甲醇 )∶V(水 ) =1∶1的溶液提取 ,经LC SAX强阴离子柱固相萃取净化 ,用RP HPLC定量分析。方法的最小检出限为 0 2 μg/ g ,在 1 0mg/L～ 2 5 0mg/L范围内有良好的线性关系 ,测定结果准确 ,重现性好 ,回收率大于 96 %。     

离心破乳-气相色谱法测定黑米中残留抑霉唑的研究

报道了离心破乳-气相色谱法测定黑米中残留抑霉唑的方法. 考察了不同离心速率、不同离心时间的破乳效率. 试样以V(正己烷):V(乙酸乙酯)＝1:1提取, 经毛细管气相色谱柱HP-5 (30 m×0.25 mm×0.25 μm)分离, μ-ECD检测器测定. 方法检出限为1.0×10-3 mg/kg (S/N=3). 在添标水平0.05、 0.25和0.50 mg/kg时的平均回收率为92.3%～104.3%, 相对标准偏差为6.9%～9.3%. 线性范围为0.02～1.0 mg/L (r2=0.9994). 方法适合黑米中残留抑霉唑的测定.     

高效液相色谱法测定水中硝基苯和苯胺含量

建立了高效液相色谱直接进样快速分析水样中苯胺和硝基苯的方法.操作条件为:进样量5 μL;流速1 mL/min;流动相为V(乙腈)∶ V(3.85 g/L乙酸铵+3 g/L乙酸)=65∶ 35混合液;苯胺用荧光分析,λex/λem =280/340 nm;硝基苯用紫外分析,波长为262 nm;分离柱为Eclipse XDB2-C8 柱(150 mm×4.6 mm, 5 μm);测试时间为3.2 min;样品前处理方法:1.0 mL水样与1.0 mL甲醇混匀,用微孔滤膜(0.45 μm, 有机系)过滤.苯胺和硝基苯标准曲线的线性相关系数均 >0.999.测试苯胺、硝基苯时,仪器精密度分别为1.56%和0.13%.方法的回收率在89%～110%之间.仪器对苯胺和硝基苯的检出上限分别是50和200 mg/L; 苯胺和硝基苯的方法检出限分别是18和21 μg/L.     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.     

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%).