高效液相色谱法检测胃液中色氨酸和利多卡因

采用高效液相色谱-紫外-荧光和高效液相色谱-紫外-质谱联用法,证明胃癌患者胃液中存在的荧光物质主要为色氨酸.建立了反相高效液相色谱-双波长同时紫外检测法定量分析胃液中色氨酸和利多卡因的方法.使用Kromasil C18柱(150 mm×4.6 mm, 5 μm),以含0.1%三氟乙酸的甲醇溶液与含0.1%三氟乙酸水溶液为流动相,梯度洗脱分析.色氨酸使用278 nm检测,浓度在0.5～200 mg/L范围内峰面积对浓度的线性相关系数为0.9994;利多卡因使用254 nm检测,浓度在20～5000 mg/L范围内相关系数为0.9992.色氨酸和利多卡因的检出限分别为0.15和5 mg/L;平均加标回收率分别为70.8%～110.4%(色氨酸) 和87.1%～116.2% (利多卡因).利用本方法对38例胃癌患者和48例非胃癌患者的胃液进行测试,两组胃液中色氨酸的含量存在一定的差异.     

高效液相色谱法测定化妆品中的12种紫外吸收剂

建立了高效液相色谱同时测定化妆品中12种紫外吸收剂含量的方法。样品用甲醇提取,高速离心,过滤,以SB-C8柱(250 mm×4.6 mm, 5 μm)为分离色谱柱,甲醇和0.1%(v/v)甲酸水溶液为流动相,梯度洗脱,以311 nm为检测波长进行定性、定量分析。该方法前处理简单、易操作,12种紫外吸收剂分离效果良好;在1.0～500 mg/L范围内呈线性关系,相关系数大于0.9995;方法检出限为0.002～0.1 mg/L;实际样品中的加标回收率为97.4%～107.5%,相对标准偏差为1.54%～4.98%。该方法简便、准确,能够满足化妆品中紫外吸收剂的检测要求。     

一种简便的双酚A高效液相色谱检测方法

建立了用紫外检测器高效液相色谱法(HPLC)代替荧光检测器HPLC法检测去除双酚A过程中,双酚A残留量的分析方法.采用Symmetry C18柱(5μm,4.6 mm i.d.×150 mm),以V(甲醇):V(水):V(乙腈):V(四氢呋喃)=40:44:8:8为流动相,流速为1.0 mL/min,紫外检测波长为276 nm,柱温为室温,进样量50μL.双酚A在0.500～20.0 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1.5%(n=6),回收率在99.98%～100.13%之间,该方法简便、准确、价廉,可用于去除环境中双酚A的跟踪检测.     

固相萃取-柱后衍生-反相高效液相色谱法测定脱水蒜粉中的亚硫酸盐

建立了测定脱水蒜粉中亚硫酸盐含量的柱后衍生-反相高效液相色谱分析方法.样品用HCl/甘露醇缓冲溶液提取,经固相萃取(SPE)小柱净化本底并富集待测物后,与甲醛缓冲液反应生成稳定的化合物羟甲基磺酸盐,采用高效液相色谱柱及柱后衍生分离,紫外检测器检测,外标法定量.色谱柱为:Agila Venusil MP-C18(4.6 mm×250 mm),流动相为0.005 mol/L四丁基氢氧化铵离子溶液(pH 4),检测波长为450 nm,结果表明,检出限为2.0 mg/kg,在0.1～10.0 μg/mL范围内线性关系良好,相关系数R2=0.9998,样品添加回收率为86.5%～97.6%,RSD为2.2%～4.0%(n=5).     

高效液相法测定牛肉干制品中10种杂环胺含量

建立了固相萃取-高效液相色谱同时分析牛肉干制品中10种杂环胺含量的方法。样品经二氯甲烷(含5%甲苯)萃取,丙基磺酸(PRS)柱和C18固相萃取小柱净化后,以甲醇-氨水定容,经TSK-gel ODS-80TM色谱柱分析,采用乙腈和0.05 mol/L醋酸-醋酸铵缓冲液(pH 3.5)作为流动相进行梯度洗脱,紫外-荧光检测器的串联方式检测杂环胺含量。结果表明,10种杂环胺在线性范围内线性关系良好,相关系数r＞0.999,检出限为0.02～2.46 ng/g。杂环胺的加标回收率为61.69%～101.81%,相对标准偏差(RSD)为0.28%～7.81%。8种市售牛肉干制品中均检测出1-甲基-9H-吡啶并［4,3-b］吲哚(Harman)和9H-吡啶并［4,3-b］吲哚(Norharman),可测杂环胺总量为16.65～60.38 ng/g。该方法线性范围广,灵敏度高,净化效果好,可满足实际样品分析的需求。     

食用菌中多菌灵残留的分散固相萃取/高效液相色谱法测定

建立了食用菌中多菌灵残留量的测定方法.采用乙腈提取样品,提取液经十八烷基硅烷(ODS)和乙二胺-N-丙基硅烷(PSA)吸附净化后,采用反相高效液相色谱-紫外可见检测器进行测定,外标法定量.色谱条件:色谱柱为Agilent Eclipse XDB C18柱(4.6 mm×150 mm,5 μm,i.d.),流动相为甲醇-0.02 mol/L磷酸盐缓冲溶液(pH 7.4)(体积比25 ∶ 75),流速1 mL/min,柱温30 ℃,检测波长282 nm.结果表明,多菌灵在0.05 ～10 mg/L质量浓度范围内线性良好,相关系数为0.999 9;方法的相对标准偏差(RSD)不大于3.4%,添加回收率为81% ～98%;多菌灵在食用菌中的检出限(LOD)和定量下限(LOQ)分别为0.03、0.10 mg/kg.该方法操作简单快速、准确度高,能够满足多菌灵残留限量标准的检测要求.     

高效液相色谱紫外检测法同时测定小鼠红细胞中S-腺苷甲硫氨酸和S-腺苷同型半胱氨酸

建立了高效液相色谱紫外检测同时测定红细胞中S-腺苷甲硫氨酸(SAM)和S-腺苷同型半胱氨酸(SAH)的方法。采用ZORBA×Eclipse×DB-C8色谱柱(150 mm×4.6 mm,5μm),以含3 mmol/L庚烷磺酸钠的40 mmol/L磷酸钠缓冲溶液(pH 3.72)-甲醇(95∶5,V/V)为流动相,流速0.9 mL/min,柱温35℃,紫外检测波长设置:0～8.00 min,450 nm;8.01～16.00 min,260 nm。SAH与SAM的线性范围分别为0.25～3.0 mg/L和0.50～10 mg/L,检出限分别为0.15和0.07 mg/L。方法日内和日间相对标准偏差(RSD)分别小于6.5%和7.4%,平均回收率为80.9%～116.2%。利用本方法对19例叶酸缺乏孕小鼠和11例健康对照孕小鼠红细胞进行测定。结果表明:叶酸缺乏组SAH明显高于健康对照组,而SAM两组间无显著差异。     

柱前衍生反相高效液相色谱-荧光检测法测定大鼠血浆中的奈替米星

建立了一种简便、灵敏的氯甲酸芴甲酯(FMOC-Cl)柱前衍生反相高效液相色谱-荧光检测血浆中奈替米星的新方法,同时研究了其药代动力学。对色谱条件进行了优化,采用ZORBAX Eclipse XDB-C8柱(150 mm×4.6 mm,5 μm),流动相为乙腈-水(体积比为85:15),流速为1.0 mL/min,荧光检测激发波长为265 nm,发射波长为315 nm,得到奈替米星的平均加标回收率为96.62%～100.84%(n=3),对奈替米星检测的线性范围为0.045～8.88 mg/L,相关系数为0.9993,方法的日内与日间精密度分别低于3%与3.5%,最低检出限(S/N=3)与定量限(以3倍检出限计)分别为0.01和0.03 mg/L。方法简便、快速、灵敏,样品用量少(30 μL奈替米星血浆溶液已能满足该药含量的测定以及药物代谢的研究),为大鼠体内奈替米星的药代动力学研究提供了可靠的分析手段。     

紫外/二极管阵列检测器液相色谱法分析甲苯法生产己内酰胺的精制副产物

建立了用二极管阵列检测器扫描紫外最大吸收波长,用高效液相色谱紫外检测器测定甲苯法生产己内酰胺精制单元副产物的方法.检测紫外最大吸收波长时使用Lichrospher C18柱(250 mm×4.5 mm i.d.,5μm),流动相为65%的甲醇水溶液,流速0.7 mL/min;定性定量使用Agilent Hypersil ODS C18柱(5μm4.0×250 mm),检测波长215 nm,流动相为V(甲醇):V(水)=38:62溶液,磷酸调节pH为5,流速0.4 mL/min.经理论推导,用保留时间结合各物质的紫外光谱定性,外标法定量.确定该副产物中主要含有环已胺、已内酰胺、苯甲酰胺、环己甲酰胺.环己胺的回收率为98%～99%,精密度为O.23%～1.51%,定量下限为0.05 mg;己内酰胺的回收率为98%～100%,精密度为0.51%～1.63%,定量下限为0.03 mg;苯甲酰胺的回收率为100%～101%,精密度为0.52%～2.02%,定量下限为0.03 mg;环己甲酰胺的回收率为97%～100%.精密度为0.73%～1.25%,定量下限为0.04 mg.     

高效液相色谱法测定铼

采用反相液相色谱法,在Agilent ODS C18(4.6×150mm)色谱柱上,以V(甲醇):V(水)=30:70为流动相,流速为0.8 mL/min,紫外检测波长为254砌对铼进行分离和检测.ReO4-在1～40 mg/L浓度范围内与峰面积线性关系较好(R=0.9992),回收率为101.4%～102.2%,重复性实验标准偏差(RSD)为1.11%.     

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.