气相色谱-质谱法测定血浆中双氯芬酸钠的含量

提出了应用气相色谱-质谱法测定血浆中双氯芬酸钠含量。血浆样品中双氯芬酸钠经盐酸提取,并加入三甲基硅烷衍生化试剂进行衍生化,所得衍生化产物经萃取、净化后供气相色谱分离及质谱测定。采用选择离子质谱扫描方式,供试品双氯芬酸钠-三甲基硅烷衍生物定量选择离子检测质荷比为m/z367,内标物布洛芬-三甲基硅烷衍生物定量选择离子检测质荷比为m/z263。双氯芬酸钠的线性范围为0.005～5.0mg·mL-1,检出限(3S/N)为0.5μg.L-1。方法回收率在94.6%～97.4%之间,日内、日间相对标准偏差(n=6)均小于5%。     

反相高效液相色谱/电喷雾质谱法测定血浆中盐酸舍曲林

采用反相高效液相色谱-电喷雾质谱法(LC-ESI/MS)测定人体血浆中盐酸舍曲林。以盐酸丙咪嗪为内标,按内标法定量。血浆样品经pH 10.00碳酸钠溶液碱化,加入甲基叔丁基醚萃取,离心分离,取上清液吹干,用流动相溶解进样。色谱柱:RP-Extend-C18(150 mm×4.6 mm,5μm),柱温:40℃;流动相:pH 3.00的三氟乙酸溶液-甲醇(40∶60,V/V),流速0.6 mL/m in。质谱采用选择离子监控模式,检测离子的核质比(m/z)分别是281(丙咪嗪)和159(舍曲林)。舍曲林和丙咪嗪的保留时间分别是5.4 m in和3.8 m in;舍曲林标准曲线线性范围为1~80μg/L;检出限为1.0μg/L(S/N>10);日间、日内相对标准差均小于6.0%,相对回收率为90%~106%;提取回收率在75%~93%范围内。此法适合人体药代动力学的血浆样品的分析,结果准确、可靠。     

液相色谱-串联质谱法确证分析环境水样中痕量克百威北大核心CSCD

采集水样后,立即按比例在每升水样中加入1.0mol·L-1硝酸溶液5mL,并于4℃温度下保存。取此水样9.0mL,加入甲酸-乙腈(1+99)混合液1.0mL,混匀,经0.2μm滤膜过滤。滤液按工作条件在Shim-pack XR-ODS II色谱柱上分离,以0.01%(体积分数)甲酸溶液-乙腈(3+7)混合液作流动相进行洗脱。洗脱液按选定条件泵入质谱离子源,在ESI+模式下,克百威的准分子离子为m/z 222.2[M+H]+,MS/MS裂解最强和次强碎片离子分别为m/z 123.0和m/z165.1,两者的峰强比为Im/z123.0∶Im/z165.1=100∶20。选择离子对m/z 222.2/123.0和m/z222.2/165.1作为定性分析离子对,并选择前者作为定量分析离子对。所提出的克百威的可能裂解途径采用Q Exactive高分辨质谱予以确认。在水样分析中,根据分析对象色谱分离的保留时间(2.67min)和裂解后的碎片离子及其峰的强度比,与克百威标准溶液的结果比较,即可判定水样中是否存在克百威。定量分析的结果表明:克百威质量浓度在0.05~10.0μg·L^(-1)内与对应的峰面积呈线性关系,其检出限(3S/N)为0.01μg·L^(-1)。用标准加入法进行回收试验,测得回收率在88.4%~96.5%之间。精密度试验的结果表明:其日内相对标准偏差(n=6)在0.90%~5.6%之间,日间相对标准偏差(n=6)在1.8%~7.3%之间。     

固相萃取纯化-高效液相色谱-串联质谱法测定尿液中痕量雷公藤红素

提出了尿液中雷公藤红素的高效液相色谱-串联质谱测定方法。尿液样品经Waters Oasis HLB固相萃取柱富集、净化后,以XDB C18反相色谱柱(150 mm×4.6 mm,5μm)为分离柱,以0.5 g.L-1乙酸-乙腈(25+75)混合溶液为流动相,以氢化可的松为内标,采用负离子模式大气压化学电离源在多反应监测模式下进行检测,雷公藤红素和内标的定量离子对分别为m/z449/405和m/z419/329。线性范围为0.2~50.0μg.L-1,检出限(3S/N)为0.07μg.L-1。日内精密度(n=6)和日间精密度(n=15)分别小于9.3%和11.4%。     

同位素稀释结合固相萃取快速测定动物组织中β2-兴奋剂

本文采用同位素稀释结合固相萃取技术,测定动物组织中特布他林、克伦特罗、沙丁胺醇、莱克多巴胺4种β2-兴奋剂。动物组织加同位素内标D3-沙丁胺醇和D9-克伦特罗,经甲醇提取后,正己烷脱脂,过SLS离子交换固相萃取柱净化,用BSTFA 1%(φ)TMCS衍生,采用GC/MS进行测定,内标法定量。实验表明,动物组织中添加2.0~10.0μg/kg浓度水平的β2-兴奋剂,方法回收率在72.5%~97.9%,相对标准偏差1.0%~11.4%,线性范围为12.5~500μg/L,样品中特布他林、克伦特罗、沙丁胺醇、莱克多巴胺最低检出限分别为0.5μg/kg、1.0μg/kg、0.5μg/kg和1.0μg/kg。     

液相色谱-串联质谱法确证分析环境水样中痕量克百威

采集水样后,立即按比例在每升水样中加入1.0mol·L-1硝酸溶液5mL,并于4℃温度下保存。取此水样9.0mL,加入甲酸-乙腈(1+99)混合液1.0mL,混匀,经0.2μm滤膜过滤。滤液按工作条件在Shim-pack XR-ODS II色谱柱上分离,以0.01%(体积分数)甲酸溶液-乙腈(3+7)混合液作流动相进行洗脱。洗脱液按选定条件泵入质谱离子源,在ESI+模式下,克百威的准分子离子为m/z 222.2[M+H]+,MS/MS裂解最强和次强碎片离子分别为m/z 123.0和m/z165.1,两者的峰强比为Im/z123.0∶Im/z165.1=100∶20。选择离子对m/z 222.2/123.0和m/z222.2/165.1作为定性分析离子对,并选择前者作为定量分析离子对。所提出的克百威的可能裂解途径采用Q Exactive高分辨质谱予以确认。在水样分析中,根据分析对象色谱分离的保留时间(2.67min)和裂解后的碎片离子及其峰的强度比,与克百威标准溶液的结果比较,即可判定水样中是否存在克百威。定量分析的结果表明:克百威质量浓度在0.05~10.0μg·L~(-1)内与对应的峰面积呈线性关系,其检出限(3S/N)为0.01μg·L~(-1)。用标准加入法进行回收试验,测得回收率在88.4%~96.5%之间。精密度试验的结果表明:其日内相对标准偏差(n=6)在0.90%~5.6%之间,日间相对标准偏差(n=6)在1.8%~7.3%之间。     

超声衍生萃取-气相色谱-质谱法测定土壤中茅草枯含量

以乙二胺四乙酸四钠盐为配位体,五氟苄基溴为衍生剂,取土壤样品(4.0g),石英砂(2g),Na4-EDTA(0.2g)和水1.0mL混匀并放置,使其水分挥发尽后加入丙酮4mL,300g·L-1五氟苄基溴溶液100μL和300g·L-1碳酸钾溶液100μL,进行超声衍生萃取。取上清液1.0mL,吹氮至近干,加入正己烷1.0mL,再次吹氮至近干,定容至1mL,按仪器工作条件进行测定。用HP-5MS毛细管色谱柱进行分离。质谱测定中用负化学离子源。线性范围为2.5~200μg·kg-1,检出限(3S/N)为0.34μg·kg-1。以土壤样品为基体,用标准加入法进行回收试验,测得回收率在89.1%~106%之间,测定值的相对标准偏差(n=7)在9.9%~11%之间。     

加速溶剂萃取分离-气相色谱-质谱法测定土壤中多溴二苯醚和六溴联苯的含量

称取经风干和剔除砂、石等杂质并研磨通过0.18 mm孔径筛的土壤样品2.000g与2.0g硅藻土混合,加入2 000μg·L-1同位素内标溶液(MBDE-MXFS)50μL和5 000μg·L-113C12-BDE-209标准溶液40μL,用正己烷-二氯甲烷(1+1)混合液进行加速溶剂萃取(ASE)。将所得萃取液浓缩至1~2mL,通过多层复合酸碱硅胶层析柱净化,用正己烷100mL洗脱,收集洗脱液,使其浓缩至1~2mL,再经氮吹浓缩至0.1mL,加入2 000μg·L-1 13C12-BDE-138进样内标溶液50μL,定容至1.0mL,进样进行气相色谱-质谱分析。测定三溴至七溴代二苯醚(BDEs)和六溴联苯(BB-153)时,按气相色谱-电子轰击离子源-低分辨质谱工作条件并选用Rtx-1614色谱柱(30m×250μm,0.10μm);测定BDE-209时,按气相色谱-负化学电离源-低分辨质谱工作条件并选用Rtx-1614色谱柱(15m×250μm,0.10μm)。测得BDE-209的线性范围为50.0~1 000μg·L-1,其余7种PBDEs和BB-153的线性范围均为5.00~500μg·L-1;检出限(3s)在0.04~0.51μg·L-1。用标准加入法进行回收试验,测得回收率为82.6%~112%;测定值的相对标准偏差(n=5)为1.8%~8.6%。     

气相色谱-串联质谱法测定尿样中氰离子的含量

尿样1.00 mL,加入1.0 g·L-1乙酸-α-萘酯溶液10μL,涡旋混合10 min后,加入0.1 mol·L-1硫酸铜溶液0.1 mL,0.3 mol·L-1萘胺溶液0.5 mL,50.0 g·L-1亚硝酸溶液1 mL和1 mol·L-1盐酸溶液0.1 mL,涡旋混合3 min。所得溶液在4℃冷藏10 min,再于50℃加热10 min。离心后,取有机相采用DB-5MS毛细管色谱柱进行气相色谱分离。质谱分析中采用选择反应监测模式。氰离子的质量浓度在0.1~10 mg·L-1范围内与其色谱峰面积呈线性关系,检出限(3S/N)为0.015 mg·L-1。按标准加入法进行回收试验,回收率在90.2%~106%之间,测定值的相对标准偏差(n=6)均小于3.5%。     

高效液相色谱-串联质谱法对家畜尿液中苯乙醇胺A残留检测研究

建立了高效液相色谱-串联质谱(HPLC-MS/MS)检测猪尿、牛尿和羊尿中苯乙醇胺A残留的方法。尿液经酶解、加入内标物、乙酸乙酯萃取、MCX固相萃取柱净化后,供HPLC-MS/MS检测。采用电喷雾离子源正模式,在多反应检测(MRM)模式下分析,苯乙醇胺A定性离子对分别为m/z 345/150和345/327,定量离子对为m/z 345/327;苯乙醇胺A内标物定性离子对为m/z 348/330,定量离子对为m/z 348/330。苯乙醇胺A含量在0～50.0μg/L范围内的线性关系良好(R2=0.9990);检出限为0.03μg/L,定量限为0.1μg/L。在猪尿、牛尿和羊尿中的回收率分别78.4%～82.9%,85.7%～93.3%和79.8%～84.9%;相对标准偏差分别为0.8%～4.2%,1.6%～5.6%和2.9%～5.8%。     

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.     

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。     

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.     

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^-。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

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)。     

Stages of thermal decomposition of sodium oxo-salts of sulphur

Thermal behaviour of sodium oxo-salts of sulphur: Na₂SO₄, Na₂S₂O₇, Na₂S₂O₆, Na₂SO₃, Na₂S₂O₅, Na₂S₂O₄, Na₂S₂O₃, Na₂S₃O₆ and of sulphides Na₂S and Na₂S₂ was studied on heating up to 1000°C. The experiments were performed with anhydrous compounds obtained from commercial products by recrystallisation and dehydration. The stage mechanisms of decomposition of anionic sub-lattices of the salts have been proposed basing on the Górski’s morphological classification of simple species. The thermal stability and the stage decomposition mechanisms were correlated with the structure and the potential chemical properties of the salt anions. The thermal decomposition processes were studied by means of thermal analysis, and the decomposition products were identified by means of X-ray phase analysis.