高效液相色谱法测定水性涂料中的酚类防霉剂

建立了简便、准确的高效液相色谱法检测涂料样品中五氯苯酚(PCP)、四氯苯酚(TeCP)和邻苯基苯酚(OPP)。选用C18柱为分离柱,以甲醇-10 mmol/LNH4Ac为流动相进行梯度洗脱,二极管阵列检测器检测,检测波长为220 nm。在该色谱条件下,PCP、TeCP、OPP分析线性范围分别为0.02~200 mg/L,0.02~200 mg/L,0.04~200 mg/L;最低检测浓度分别为0.01、0.01、0.02 mg/L,分别相当于涂料中的质量分数为5.0×10-4%,5.0×10-4%,1.0×10-3%;方法加标回收率为96.6%~103.6%,相对标准偏差为0.98~4.3%(n=7)。本法能满足涂料中PCP、TeCP、OPP的分析测定。     

高效液相色谱-二极管阵列检测法测定L-丙氨酸与L-氨基丙醇

建立了柱前衍生同时测定L丙-氨酸、L氨-基丙醇的高效液相色谱方法。色谱条件为:Shim-pack VP-ODS柱(150 mm×4.6 mm.ID.,5μm);二极管阵列检测器;流动相为甲醇-磷酸盐缓冲溶液(NaH2PO4浓度为0.02 mol/L,pH 4.00 H3PO4调节)(体积比为30∶70),流速为0.5 mL/m in,检测波长为222 nm,柱温为30℃。L丙-氨酸与L氨-基丙醇的线性范围分别为2.30~178 mg/L和9.3~8690 mg/L;检出限分别为1.1 mg/L和1.6 mg/L;日内、日间测定的相对标准偏差(RSD)分别为0.22%、0.46%和0.02%、0.03%。     

超高效液相色谱法同时测定布洛芬注射液中布洛芬和精氨酸的含量

建立了一种同时测定布洛芬注射液中布洛芬和精氨酸含量的超高效液相色谱方法。精氨酸与衍生化试剂2,4-二硝基氟苯(DNFB)反应后,与布洛芬同时在超高效液相色谱-二极管阵列检测器(UPLC-PDA)上检测。采用BEH C18色谱柱(50 mm×2.1 mm, 1.7 μm),以乙腈-0.05 mol/L磷酸二氢钾缓冲液(pH 2.5)为流动相进行梯度洗脱,流速为0.4 mL/min,柱温为30 ℃,检测波长分别为357 nm(精氨酸衍生物)和220 nm(布洛芬)。结果表明,布洛芬与精氨酸分别在2.0～100.5 mg/L和1.7～84.5 mg/L范围内呈良好的线性关系,相关系数(r)均为0.9997;平均回收率分别为99.8%和99.6%,相对标准偏差(RSDs)分别为0.37%和0.25%;定量限(信噪比（S/N）=10)分别为0.1 ng和0.2 ng;检出限(S/N=3)分别为0.03 ng和0.05 ng。本方法快速、准确,重复性好,可较全面地评价布洛芬注射液的质量。     

高效液相色谱法测定人血浆中的芦氟沙星

 建立了测定人血浆中芦氟沙星质量浓度的高效液相色谱法 ,血浆用二氯甲烷提取 3次 ,以 UltrasphereODS(4.6mm i.d.× 2 5 0 mm)为色谱柱 ,流动相为甲醇 -1 0 mmol/L 溴化四丁铵 -三乙胺 (体积比为 3 2∶ 68∶0 .5 ) ,用磷酸调 p H2 .8,检测波长 2 95 nm,流速为 1 .2 m L/min,以培氟沙星为内标。血浆中芦氟沙星的线性范围为 0 .1～ 1 0 mg/L ,最低检测质量浓度为 0 .0 5 mg/L ,回收率为 99.7% ,日内、日间 RSD分别为 2 .3 3 %和3 .83 %。方法简便、快速、准确 ,适用于人血浆中芦氟沙星质量浓度的测定。     

非水介质毛细管电泳电化学检测日夜百服宁中的有效成分

用非水毛细管电泳电化学检测法分离检测了日夜百服宁中的有效成分，研究了电极电位，不同浓度的甲酰胺（FA），电解液浓度和酸度，电泳电压及进样时间对电泳分离的影响，得到了较为优化的测定条件。实验结果表明，在25mmol/L Tris-25mmol/L H3BO3(表观pH=8.5)运行介质中，日夜百服宁中的4种有效成分即扑热息痛（AP），盐酸伪麻黄碱（PH），氢溴酸右美沙芬（DM）和扑尔敏（CM）在12min内完全分离，检测电位为＋0．9V(vs.SCE)。线性范围分别为AP 0．5－200mg/L;PH 0.8-300mg/L;DM2.5-350mg/L;CM0.5-330mg/L；检测限分别为AP0.1mg/L;PH0.55mg/L;DM1mg/L;CM0.2mg/L。     

反相高效液相色谱法测定小鼠血浆及组织中的阿昔洛韦浓度

 建立了测定小鼠血浆、肝、肾、脾、肺等组织中阿昔洛韦 (ACV)浓度的高效液相色谱法。色谱柱为HypersilODS ,流动相为甲醇 水 冰醋酸 (体积比为 1∶99∶0 5 )混合溶液 ,流速为 1 5mL/min ,检测波长为 2 5 2nm。ACV血浆最低检测浓度为 2 0 μg/L ,各组织最低检测浓度为 5 0ng/g。血浆及组织匀浆中的ACV浓度在 0 1mg/L～ 4mg/L及 0 1μg/g～ 4μg/ g时线性关系良好 (r >0 99)。血浆及肝匀浆中的ACV回收率分别为 97 5 %～ 10 0 0 %和 10 0 0 %～ 10 6 0 % (n =5 )。该法精密度高 ,方便 ,快捷 。     

固相萃取-反相高效液相色谱法同时测定饲料中的角黄素和虾青素

建立了一种同时测定饲料中角黄素和虾青素的固相萃取-高效液相色谱法（HPLC）。样品由乙腈提取,经LC-NH2固相萃取小柱净 化,洗脱剂为乙腈-甲苯（体积比为3∶1）,洗脱液被浓缩后进行HPLC分析,色谱柱为ZORBAX Eclipse XDB-C18柱(150 mm×4.6 mm,5 μ m),流动相为乙腈-甲醇（体积比为95∶5）,流速1.0 mL/min,采用二极管阵列检测器检测,检测波长为474 nm;外标法定量。角黄素和 虾青素的线性范围分别为1.0～30.0 mg/L和1.0～20.0 mg/L,相关系数分别为0.9990和0.9991,回收率为90%～101%,相对标准偏差为 0.62%～3.68%,检出限分别为0.84和0.60 mg/L。该方法简便、快速、准确,可用于饲料中角黄素和虾青素的同时测定。     

高效液相色谱法测定人血浆及尿液中头孢呋辛和舒巴坦

建立反相HPLC-UV法同时测定人血浆及尿中头孢呋辛(CXM)和舒巴坦(SUL)的方法.采用Welch Materials XB-C18分析柱(150 mm×4.6 mm,5 μm ) ,流动相为乙腈-0.01 mol/L KH2PO4 (血浆测定15∶ 85(V/V),尿样测定10∶ 90(V/V),含0.04%三乙胺,以H3PO4调节至pH 3.2),流速1.0 mL/min,紫外检测波长SUL为220 nm、CXM及内标咖啡酸为274 nm.血浆样品在酸性条件下用乙醚提取浓集后进样,以内标法进行定量分析.尿样稀释后直接进样,以外标法进行定量分析.血浆测定中SUL和CXM浓度分别在0.25～200 mg/L和0.5～400 mg/L范围内线性良好; 萃取回收率分别为75.6%～88.1%和68.6%～77.4%; 批内与批间RSD均小于9%,方法回收率分别为94.6%～113.6%和91.9%～101.8%.尿样中SUL和CXM浓度分别在5～5120 mg/L和10～10240 mg/L范围内线性良好; 批内与批间RSD均小于3%; 方法回收率分别为92.9%～111.1%和98.0%～105.3%.本方法快速简便, 灵敏准确,可用于同时测定血浆及尿中SUL和CXM浓度,亦可用于药代动力学、生物利用度研究.     

固相萃取高效液相色谱-质谱法测定血浆中乙醇醛、甘油醛的含量

采用柱前衍生、固相萃取、高效液相色谱-质谱联用方法,建立了血浆中乙醇醛(GCO)、甘油醛(GCE)含量的测定方法。衍生试剂为3-m ethyl-2-benzoth iazolinone-hydrazone hydrochloride(MBTH);内标物为3-羟基丁醛;HPLC流动相为甲醇-醋酸铵(5 mmol/L),梯度洗脱;质谱电喷雾选择离子检测。比较了糖尿病大鼠和正常大鼠血浆中GCO、GCE的含量,正常大鼠血浆中GCO和GCE的含量分别为0.0574±0.0036μmol/L、0.0186±0.0019μmol/L;糖尿病大鼠血浆中GCO和GCE的含量分别为0.0763±0.0071μmol/L、0.0240±0.0023μmol/L,差异显著。     

固相萃取–高效液相色谱法测定豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的残留量

建立了测定豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的固相萃取–高效液相色谱法。样品以0.1 mol/L的盐酸溶液为提取剂,经C18固相萃取柱净化处理,以乙腈–10 mmol/L乙酸铵水溶液(体积比25∶75)为流动相,Tech Mate C_(18)–ST色谱柱分离,4-氯苯氧乙酸钠和6-苄基腺嘌呤的紫外检测波长分别为228 nm和267 nm,色谱峰面积外标法定量。在0.50~100.00 mg/L浓度范围内,4-氯苯氧乙酸钠的相关系数为0.999 8,精密度在1.3%~8.2%之间(n=6),回收率在103.1%~109.0%之间;在0.05~10 mg/L浓度范围内,6-苄基腺嘌呤相关系数为0.999 9,精密度在0.9%~3.8%之间(n=6),回收率在88.0%~95.4%之间。4-氯苯氧乙酸钠和6-苄基腺嘌呤的检出限(S/N=3)分别为0.24,0.02 mg/kg。该法可以同时完成豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的分析检测。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。     

微量钙的测定方法研究进展

介绍了1995-2006年期间测定微量和痕量钙的方法,如电感耦合等离子体-原子发射光谱法、原子吸收光谱法以及离子色谱法等的工作原理和特点,并说明了其测定微量钙的应用领域。并对微量钙的测定技术进行了展望(引用文献55篇)。