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)。     

鱼腥草中3种有效成分含量的测定

建立鱼腥草不同品种、不同部位绿原酸、芸香苷和槲皮素的测定方法. 以90% EtOH为溶剂, 采用索氏提取器提取, 利用HPLC测定3种活性成分的含量. 采用DiamonsilTMC18 (4.6 mm×150 mm, 5 μm)为色谱柱, 流动相分别为0.06 mol/L V(NaH2PO4)∶V(MeOH)＝7.3∶2.7、 V(MeOH)∶V(H2O)∶V(HAc)＝48∶50∶2, 流速为1 mL/min, 绿原酸检测波长为326 nm, 芸香苷和槲皮素为254 nm. 绿原酸、芸香苷、槲皮素的线性范围分别为4.6～30.7 μg/mL、 0.30～7.5 μg/mL、 0.034～0.85 μg/mL, 平均回收率和RSD分别为99.3%、 1.0%, 98.9%、 1.6%, 98.7%、 0.7%. 该方法可用于鱼腥草原料选择和制剂质量的控制.     

KBrO3氧化甲基紫褪色动力学光度法测定食品中痕量钒

基于0.004 mol/L的柠檬酸介质中,痕量V(Ⅴ)催化KBrO3氧化甲基紫的褪色反应,建立了测定痕量V(Ⅴ)的动力学光度法。方法的检出限为1.23μg/L,线性范围为0～0.16μg/mL。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响,确定了该体系反应的最佳条件。在25 mL溶液中,测定2.0μg V(Ⅴ)的RSD为1.9%(n=11)。方法可用于测定小麦和苹果中的痕量V(Ⅴ),RSD为1.1%～2.7%,标准加入回收率为97.6%～99.0%。     

反相高效液相色谱法同时测定水样中辛硫磷和氯菊酯

采用AgilentSBC8(5μm,4.6mmi.d.×150mm)色谱柱,以V(乙腈)∶V(水)=70∶30为流动相进行分离,二极管阵列检测器(PDA)在210nm波长处检测,建立了反相高效液相色谱法同时测定辛硫磷和氯菊酯的分析方法。辛硫磷和氯菊酯的线性范围分别为0.1～10μg mL和0.02～10μg mL,检出限分别为0 05和0.01μg mL,实际水样的加标回收率为90.3%和95.3%,相对标准偏差为1.3%和3.2%(n=7)。     

高效液相色谱法测定红霉素、甲红霉素和罗红霉素的研究

建立了高效液相色谱-荧光法同时测定红霉素、甲红霉素、罗红霉素的方法。该方法以9-芴代甲氧苯酰氯(FMOC-CL)为衍生试剂,以V(乙腈)∶V(磷酸二氢钾)=3∶1为反应体系,于50℃反应1 h。液相色谱分析条件为:Extend-C18柱(4.6 mm i.d.×150 mm),乙腈-25 mmoL磷酸二氢胺(pH 7)为流动相,梯度淋洗;柱温30℃,流速1.5 mL/min,激发波长255 nm、发射波长315 nm。线性范围分别为红霉素0.5~100μg、甲红霉素0.5~100μg、罗红素0.1~150μg。检出限为红霉素1μg/mL、甲红霉素1μg/mL、罗红霉素0.25μg/mL。加标回收率为90%~97%,相对标准偏差为3.5%~7.9%。     

液相色谱-串联质谱法同时测定红茶和绿茶中7种硫代氨基甲酸酯类除草剂

建立了红茶和绿茶中7种硫代氨基甲酸酯类除草剂(禾草敌、克草敌、灭草敌、野麦畏、禾草丹、茵草敌和丁草敌)的高效液相色谱-串联质谱(LC-MS/MS)检测方法.样品制备后,取2.0 g样品,加6 mL水浸润1 h.然后加入2.5 g NaCl,并用20 mL乙腈分两次进行提取,提取液吹氮浓缩后过HLB柱,并用3 mL乙腈洗脱.洗脱液浓缩后用2.0 mL正己烷-丙酮(7∶ 3,V/V)溶解残渣,然后过Envi-Carb固相萃取柱,再用5 mL正己烷-丙酮洗脱,洗脱液浓缩后用乙腈-水(5∶ 5,V/V)定容.采用LC-MS/MS电喷雾电离,多反应监测模式对样品进行分析.以D_3-甲萘威为内标,测定7种硫代氨基甲酸酯除草剂的线性范围为0～200 μg/L,线性相关系数在0.9954～0.9988范围内,检出限在0.093～1.77 μg/L范围内.在添加浓度5～20 μg/kg范围内,7种硫代氨基甲酸酯除草剂的回收率均在77.3%～91.5%,相对标准偏差(RSD)小于15%.本方法被成功用于红茶和绿茶样品中硫代氨基甲酸酯除草剂的测定.     

高效液相色谱法测定菌肥中赤霉素和吲哚乙酸含量方法研究

建立了一种高效液相色谱法分离测定赤霉素(GA3)和吲哚乙酸(IAA)的方法.采用Agilent ZORBA×300SB-C18(4.6 mm×250 mm)色谱柱,以甲醇∶水=35∶65,(V/V,含2%冰醋酸)为流动相,柱温为25℃,流速为0.5 mL/min.系统讨论了流动相组成及pH对分离的影响.本法测定GA3和IAA的线性范围分别为25.0~1 000μg/mL、2.5~50.0μg/mL.方法回收率分别为85.63%、90.21%.并将该方法成功应用于菌肥中GA3和IAA的含量测定,为该类产品的质量控制提供了快速有效的方法.     

离子色谱法同时测定蛋白胨中氯离子、硫酸根离子、碘离子

建立离子色谱法测定蛋白胨中氯离子、硫酸根离子、碘离子3种阴离子的含量。采用氢氧化钾淋洗液发生器产生的KOH溶液为流动相,进行梯度淋洗,流量为1.0 mL/min。氯离子、硫酸根离子的质量浓度分别在0.5～200μg/mL范围内与色谱峰面积呈良好的线性关系,碘离子的质量浓度在0.75～50μg/mL范围内与色谱峰面积呈良好的线性,线性相关系数均不小于0.999,检出限分别为0.003,0.01,0.22μg/mL。样品加标回收率为92.94%～96.59%,测定结果的相对标准偏差为2.42%～5.70%(n=9)。该方法灵敏、高效,可用于蛋白胨中氯离子、硫酸根离子、碘离子的快速准确测定。     

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 ) 。     

超声提取-反相高效液相色谱法测定新疆大蓟中绿原酸和芦丁的含量

以黄酮提取量为指标,选用正交实验对新疆大蓟总黄酮的超声提取工艺进行优化,结果表明最佳提取条件为:超声电流250mA,料液比1∶30(g/mL),时间40min,总黄酮提取量为2.89mg/g。同时建立了高效液相色谱法测定新疆大蓟中绿原酸及芦丁含量的方法。采用SinoChrom ODS-BP色谱柱,甲醇-1%冰乙酸为流动相,检测波长为340nm,流速为0.9mL.min-1。方法测定绿原酸的线性范围为1.675～16.75μg/mL,相关系数R=0.99995;测定芦丁的线性范围为2～20μg/mL,相关系数R=0.9999,回收率分别为99.45%、99.65%。该法简单准确,适用于新疆大蓟中绿原酸及芦丁的定量分析。     

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.