反相高效液相色谱法测定血浆中的辅酶Q10

建立了一种检测血浆中辅酶Q10含量的高效液相色谱法。血浆经甲醇脱脂蛋白后,以正己烷萃取,萃取液依次经硅胶柱净化、C18柱固相萃取,再进行高效液相色谱分析。色谱柱为Hypersil ODS2柱(5 μm,150 mm×4.6 mm i.d.),以异丙醇-甲醇(体积比为45∶55)溶液作流动相,辅酶Q9作内标,检测波长为275 nm。在0.1-50.0 mg/L质量浓度范围内,辅酶Q10与辅酶Q9的峰面积比与相应CoQ10的质量浓度呈良好的线性关系(r2=0.999),血浆中辅酶Q10的检测限为0.03 mg     

血浆辅酶Q10的高效液相色谱快速测定

建立了一种简单快速测定血浆辅酶Q10(CoQ10)的反相高效液相色谱方法.血浆经正丙醇萃取,上层清液直接进样分析.色谱柱为Hypersil ODS2 5μm,150 mm ×4.6 mm i.d,以异丙醇-甲醇(体积比19)作流动相,275 nm作检测波长,外标法定量.在0.05～20 mg/L范围内,峰高与质量浓度呈良好的线性关系(r=0.999 8),血浆中辅酶Q10的检出限为0.03 mg/L(S/N=3).该方法简单、快速、精密度高(RSD＜5%),适宜于血浆辅酶Q10含量的检测.     

全血中维生素E和辅酶Q10含量的高效液相色谱法测定

建立了一种同时测定全血中维生素E和辅酶Q10的高效液相色谱法.样品经乙醇沉淀蛋白,以正己烷萃取,氮气吹干后,流动相溶解,以甲醇-乙醇(体积比20 : 80)为流动相,在C18柱 (5 μm, 250 mm×4.6 mm i.d.)上进行色谱测定.维生素E和辅酶Q10的线性范围皆为1.0 ～50.0 mg/L,检出限分别为0.21、0.15 mg/L,相对标准偏差分别为5.2%、5.9%;全血样品的维生素E和辅酶Q10加标回收率分别为97%～115%和90%～112%.     

分子印迹固相萃取技术检测江水、尿液及牛奶中雌激素残留

以β-雌二醇和炔雌醇的分子印迹聚合物为填料制备固相萃取小柱,选择60%(V/V)甲醇-水溶液作为雌激素的淋洗液,甲醇-乙酸(9:1,V/V)为洗脱液,洗脱两次可彻底洗脱固相萃取小柱中目标分子.以建立的萃取条件对上海黄浦江水、尿液、牛奶中雌激素进行富集,结合高效液相色谱法,建立了基于分子印迹固相萃取技术检测上述实际样品中...     

高效液相色谱法测定饲料用灌木中色素的研究

研究了用固相萃取预分离,高效液相色谱法测定饲料用的灌木中植物的色素的方法;饲料用的灌木样品中的色素用Sep Pak C18固相萃取小柱预分离和富集,以WatersNova Pak C18液相色谱柱为固定相,V(甲醇)∶V(异丙醇)=1∶1和水梯度洗脱为流动相分离。方法可同时测定叶黄素、α 胡萝卜素、β 胡萝卜素、叶绿素 a、叶绿素 b、紫黄质、新叶黄素(新黄质)等色素,方法标准回收率为94%～104%,相对标准偏差为1 9%～2 5%。已用于几种饲料用的植物色素的测定。     

柱切换高效液相色谱法测定人血浆中布洛芬对映体浓度

建立了柱切换高效液相色谱法测定人血浆中布洛芬对映体浓度的方法。以对溴苯甲酸为内标,样品经醋酸钠缓冲液酸化后,用V(正己烷)∶V(异丙醇)=95∶5萃取。以Chiralcel OJ-H柱(Daicel Chemicals,250mm×4.6mm,5μm)为分析柱,UltimateTM SiO柱(50mm×4.6mm,5μm)为预处理柱;流动相为V(正己烷)∶V(异丙醇)∶V(三氟醋酸)=96.5∶3.5∶0.1,流速为0.5mL/min;预处理流动相为V(正己烷)∶V(异丙醇)=99.5∶1,流速为1mL/min;柱切换时间为1.70~4.09min;紫外检测波长为230nm。布洛芬消旋体和S-( )-布洛芬标准曲线线性范围分别为0.21~20mg/L和0.10~10mg/L;日内RSD小于6.5%,日间RSD小于6.1%;方法回收率为93.3%~107.1%,萃取回收率为80.0%~86.6%。本法简便、准确,重现性好,可用于布洛芬对映体人体药代动力学研究。     

非极性流动相高效液相色谱法定量测定辅酶Q10

采用高效液相色谱外标法定量测定辅酶Q10的含量.色谱条件:4.6mm×25cmZorbox CN柱;流动相:V(正己烷)∶V(异丙醇)=99.5∶0.5;流速:1.0mL·min-1;紫外检测器275nm下检测;ABS:0.04.样品检测线性范围为8μg～0.05μg;相关系数r=0.9998;回收率100.35%;精密度RSD=1.48%.     

高效液相色谱法测定全血中加替沙星

提出了用环丙沙星为内标及用荧光检测的加替沙星(GXTC)的高效液相色谱测定方法.全血样品中GXTC用pH 7.0的磷酸盐缓冲溶液萃取并经固相萃取小柱净化,用甲酸及甲醇(4+96)混合溶液作淋洗液淋洗萃取小柱,所得淋出液用吹氮法蒸干,残渣溶于1.0 mL甲醇中,分取10.0μL溶液供高效液相色谱测定.测定中用甲醇、乙腈及甲酸(2+998)溶液三者以15比15比70的体积比混合后作为流动相,在Cloversil C18柱(150 mm×3.0 mm,5 μm)上进行分离.荧光检测激发波长为288 nm,发射波长为478 nm.加替沙星在15.0～240.0μg·L-1范围内呈线性,方法回收率在97.0%～102.0%之间,日内相对标准偏差(n=6)小于6.0%,方法的测定限(10S/N)为15.0μg·L-1.     

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猪尿中克伦特罗对映异构体残留量

建立了测定猪尿中克伦特罗对映异构体残留量的高效液相色谱分析方法.在碱化的条件下,用乙酸乙酯提取10 mL猪尿样品,提取液经稀HCl反萃取,萃取液直接过SCX固相萃取小柱,再用5%氨化甲醇洗脱,洗脱液经氮气吹干后用200 μL甲醇定容.采用Astec CHIROBIOTICTM V手性色谱柱,以V(甲醇)∶ V(冰乙酸)∶ V(三乙胺)=99.94∶ 0.02∶ 0.04为流动相进行HPLC分析,检测波长301 nm,外标法定量.克伦特罗单-对映体的峰面积与其浓度在70～5000 μg/L范围内呈良好的线性; 线性相关系数均大于0.9996; 猪尿样品中检出限为0.30 μg/L.猪尿中克伦特罗对映体在1.0～20.0 μg/L范围内的添加回收率为76.3%～91.5%; 相对标准偏差RSD均小于7%(n=5).     

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.     

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.     

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.     

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.