高效液相色谱-质谱联用法检测免疫抑制剂及其合并用药

建立高效液相色谱-质谱联用法同时测定人血浆中免疫抑制剂及合并用药12种药物浓度的方法.选用Kromasil-C18色谱柱(50 mm× 4.6 mm×5 μm),以甲醇-乙腈-1mmol/L乙酸铵溶液为流动相,采用梯度洗脱进行分离,样本用甲醇沉淀蛋白后进样,流速:1.1 mL/min;柱温:35℃;进样量:20μL.选用3200QTrap型液相色谱-串联质谱仪的多反应监测(MRM)扫描方式进行检测.12种药物的线性范围为0.2～1000μg/L;定量下限为0.2 μg/L.准确度与精密度结果显示方法日间、日内RSD均小于15％;相对偏差-13％～9.33％,稳定性较好.本方法快速、灵敏,专属性强、重现性好,可用于人体血浆中免疫抑制剂及其常用合并用药共12种药物浓度的测定.     

液相色谱-串联质谱法测定牛奶中伏马菌素FB1和FB2及其水解代谢物

建立了MAX混合阴离子固相萃取柱净化-高教液相色谱-串联质谱法测定牛奶中伏马菌素FB1和FB2及其水解代谢产物HFB1和HFB2的方法.牛奶样品经水稀释后,经MAX柱直接净化,甲醇洗脱得到FB1和FB2,经液相色谱-串联质谱负离子扫描测定,1％乙酸甲醇洗脱得到HFB1和HFB2,经液相色谱-串联质谱正离子扫描测定.结果表明,添加浓度为0.1～5.0 μg/L,牛奶中FB1和FB2及其水解代谢产物的回收率为76.4％～92.3％;相对标准偏差(RSD,n=5)为5.9％～12.5％;方法检出限(LOD)均为0.03 μg/L;定量限(LOQ)均为0.1 μg/L.本方法操作简单,灵敏度、回收率和重复性均良好.     

环境水样中百菌清残留的单滴微萃取-反相液相色谱测定

应用单滴微萃取(SDME)-反相液相色谱(RPLC)检测了环境水样中的百菌清残留.优化了单滴微萃取条件:环己烷萃取剂6 μL、单滴体积2 μL、搅拌速率350 r/min、萃取时间40 min、水溶液温度35 ℃、无盐度.水样经单滴微萃取后,使用Hypersil C18柱反相液相色谱分离测定百菌清.反相液相色谱条件:100%甲醇流动相、流速1.0 mL/min、柱温25 ℃、224 nm检测.方法的线性范围、检出限、相对标准偏差和富集倍数分别为1.0 ～50 μg/L、0.02 μg/L、6.1%和427倍.采用该法对环境水样中的百菌清残留进行了测定,环境水样的加标回收率为98% ～106%.     

高效液相色谱-串联质谱法同时测定红小豆中残留的6种咪唑啉酮类除草剂

建立了同时测定红小豆中6种咪唑啉酮类除草剂残留的高效液相色谱-串联质谱分析方法。样品经0.1 mol/L NH4HCO3(pH 5)-甲醇(体积比为70∶30)溶液提取,二氯甲烷液-液萃取和凝胶渗透色谱净化后,采用Inertsil ODS-3色谱柱(2.1 mm×150 mm, 5 μm)分离,以甲醇-0.1%乙酸为流动相梯度洗脱,离子阱质谱在选择离子模式下测定。咪唑啉酮类除草剂在10～200 μg/L(灭草喹在5～100 μg/L)内线性关系良好,相关系数为0.9987～0.9997;方法的检出限为0.2～0.5 μg/kg;在红小豆中3个加标水平的平均加标回收率为81.6%～99.4%,相对标准偏差为3.1%～7.8%。该方法简便、灵敏度高、精密度好,适用于红小豆中多种咪唑啉酮类除草剂残留的测定。     

高效液相色谱-化学发光法检测牛奶中磺胺类药物残留

以4种磺胺类药物(Sulfonamides, SAs), 即磺胺脒(Sulfaguanidine, SGD)、磺胺嘧啶(sulfadiazine, SDZ)、磺胺噻唑(sulfathiazole, STZ)和磺胺二甲嘧啶(Sulfamethazine,SMZ)为分析物,基于其在碱性介质中对Ag配合物-鲁米诺(Luminol)与Ni配合物鲁米诺两化学发光体系发光强度均具有抑制作用的性质,建立了高效液相色谱-化学发光法检测牛奶中4种磺胺类药物的方法.将化学发光体系作为高效液相色谱的新型检测器,并对两种化学发光体系的检测器性能进行了比较.4种磺胺药物经高效液相色谱分离后,分别与Ag-Luminol及Ni-Luminol化学发光体系作用.色谱条件为:反相C18分离柱(250 mm × 4.6 mm,5 μm);0.1%甲酸-甲醇为流动相(V/V);梯度洗脱;流速1 mL/min.化学发光条件:Ag、Ni-Luminol两体系中,Ag配合物浓度1.4×10.-4 mol/L(含0.12 mol/L NaOH);Ni配合物浓度1.5×10.-5 mol/L(含0.12 mol/L NaOH);Luminol浓度均为1.2×10.-7 mol/L;试剂流速均为1.0 mL/min.在最佳的分离检测条件下,Ag-Luminol体系检测4种磺胺类药物的检出限分别为0.15、0.96、1.10和1.50 μg/mL,加标回收率为81.0%~101.5%;Ni-Luminol体系检测SGD、SDZ、STZ 3种磺胺类药物的检出限分别为1.5、17.2和16.8 μg/mL,加标回收率为83.9%~110.8%.相比之下,Ag-Luminol体系作为高效液相色谱检测器更佳.应用本方法对牛奶中4种磺胺类药物残留量进行检测,结果令人满意.     

超高效液相色谱串联质谱法同时测定马尾藻中4种内源性植物激素

建立了利用超高效液相串联质谱法(UPLC-MS/MS)同时测定马尾藻中4种植物激素(吲哚乙酸、吲哚丁酸、脱落酸、玉米素)的方法.马尾藻样品经过70％甲醇提取后,经PCX+PAX固相小柱净化,使用反相C18色谱柱分离.以5 mmol/L乙酸铵(含0.01％甲酸)和甲醇作为流动相进行梯度洗脱,采用多反应离子监测模式(MRM)分析测定.在0.01 ～ 1.0 μg/mL内,各种植物激素的相关系数均大于0.9990.4种植物激素的回收率为84.3％～102.1％,相对标准偏差为1.1％～6.4％.本方法的检出限为0.025～0.2μg/kg.     

超高效液相色谱-串联质谱法同时快速测定卷烟烟丝中的6种生物碱

建立了超高效液相色谱-串联质谱( UPLC - MS/MS)同时快速测定烟草中6种生物碱的方法.对样品前处理条件和仪器分离条件进行了优化,样品经去离子水超声提取后,于UPLC BEH C18色谱柱上分离,在多反应监测模式下采用同位素内标法定量以排除基质效应.结果表明,6种生物碱的线性范围为0.1～8 000 μg/L,...     

超高效液相色谱法同时测定盐酸丁丙诺啡舌下含片中丁丙诺啡和纳洛酮的含量

建立了同时检测丁丙诺啡和纳洛酮的超高效液相色谱的分析方法.分析柱为Waters Acquity BEH C18超高效液相色谱柱,紫外检测波长为280 nm,流动相为甲醇-甲酸(0.2%)水,梯度洗脱,两种分析物在3 min内即可达到良好分离.纳洛酮和丁丙诺啡的线性范围分别为1～25 μg/mL,2～50 μg/mL,线性相关系数分别为0.9992,0.9995.检出限为0.2μg/mL.考察了甲醇和乙腈两种流动相体系对样品的分离效果,发现甲醇流动相体系的响应高于乙腈流动相体系.在优化条件下,对丁丙诺啡舌下含片以及加标后样品进行测定,且对其方法学进行考察,加标平均回收率在91.3%～100.1%之间,RSD小于5%.     

磁固相萃取-高效液相色谱联用测定尿样中的1-羟基芘

采用磁固相萃取-高效液相色谱-荧光检测方法(MSPE-HPLC-FD)分析了尿样中芘代谢物1-羟基芘(1-Hydroxyperene 1-OHP).2mL尿样以0.1 mol/L醋酸钠溶液(pH 4.5)稀释至4 mL,酶水解后,再以0.1 mol/L醋酸钠溶液(pH 5.0)稀释至10mL,采用十八烷基膦酸改性的磁性介孔纳米粒子(50 mg)为萃取介质,对其进行MSPE富集,涡旋萃取1 min,甲醇解吸3min.解吸液经氮气吹干重新定容后,进行液相色谱分析.本方法在0.01～ 1.00 μg/L范围内线性良好(R2=0.9996);检出限为0.001μg/L日内相对标准偏差小于9.7％(n=5),日间相对标准偏差小于12.9％.将本方法应用于多个人体尿液样品中1-OHP含量的检测,结果满意.为确保结果的科学性和可靠性,测定结果用尿肌酐含量进行了归一化.     

液相色谱-质谱法对电子电气产品塑料部件中有机锡的测定

建立了液相色谱-质谱法同时测定电子电气产品塑料部件中3种有机锡的方法.样品经四氢呋喃溶解,并经甲醇沉淀杂质后,用液相色谱-质谱仪进行测定和确证.色谱柱为ZORBAX 300-SCX柱(250 mm×4.6 mm×5 μm i.d.),流动相为体积比80 : 20的甲醇-20 mmol/L醋酸铵(含0.01%冰乙酸),等度洗脱,流速为1.0 mL/min,选择离子监测模式.三丁基锡、三苯基锡、三辛基锡的线性范围分别为0.1 ～10.0、0.1 ～10.0、0.05 ～5.0 mg/L(相关系数r~2≥0.999 2),方法定量下限(LOQ)依次为0.005%、0.005%、0.0025%;平均加标回收率为80% ～100%,相对标准偏差为1.6% ～11.5%(n=6).     

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。     

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^-。     

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.     

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.     

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.     

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.     

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)。