用于与全二维气相色谱联用的高通量飞行时间质谱仪的研制

研制了可与全二维气相色谱联用的高通量飞行时间质谱仪,并进行了性能水平测试。设计采用新型高灵敏度电子轰击源及具有垂直引入、双推斥脉冲、二级反射式结构的飞行时间质量分析器,结合高于20 kHz的推斥频率,可获得质量范围1~1000 amu,质量分辨>1000(m/z 219,ADC采集卡),检出限低于1 pg,线性动态范围超过4个数量级,同时最快可达400谱/s的高采集速度,完全满足全二维气相色谱与飞行时间质谱联用的检测要求。与一款完全国产化的全二维气相色谱仪联用,实现对石油、香精、环境等多个领域复杂样品的分析,获得令人满意的检测结果,显示了此质谱仪器与全二维气相色谱联用的适用性及其在复杂样品体系全组分分析中的应用潜力。     

一种新型光电离/微型正交加速飞行时间质谱仪的设计和性能测试

介绍了自行研制的光电离/微型正交加速飞行时间质谱仪的设计原理和性能。电离源采用光子能量为10.6 eV真空紫外灯,它可将待测分子电离只产生单电荷母体离子,不产生碎片离子。采用该光电离方法得到的质谱谱图比较简单,气体样品可以不经分离直接进行分析。离子正交引入结构的飞行时间质量分析器有效地提高了质谱分辨率。用32 cm无场飞行管,测量碘甲烷得到的质谱分辨率可达430。在谱图获得频率10 kHz的操作条件下,样品总分析时间20 s,得到苯和碘甲烷的检出限分别为10×10-6,5×10-6。软电离和微型化使得该质谱仪在可挥发性有机物的实时在线监测方面有广泛的应用。     

离子富集脉冲电源对提高飞行时间质谱仪灵敏度的影响

研究自制离子富集脉冲电源对飞行时间质谱仪灵敏度的提高效果。离子富集脉冲电源包括脉冲信号产生模块、放大隔离模块、开关驱动模块、高压电路模块和负载阻抗匹配模块,输出一路中压脉冲信号,两路对称高压脉冲信号。利用自制电喷雾电离源及激光解析电离源与飞行时间质谱仪联用,调试中压脉冲信号。结果显示,应用离子富集脉冲电源后仪器对不同样品的检测灵敏度可提高6~24倍。     

宽离子能量检测范围垂直引入反射式飞行时间质谱仪的研制

本实验室研制了国内首台宽离子能量检测范围飞行时间质谱仪。仪器采用紧凑式电子轰击源设计,配合离子透镜系统有效的调制离子流,飞行时间质量分析器采用了离子垂直引入式,双场加速和双场反射以及大尺寸MCP检测装置设计。仪器单离子信号半峰宽约2 ns,仪器分辨率优于1600FWHM,检测实际样品质量范围为1~127 amu(仪器理论质量检测上限优于800 amu),可检测离子能量范围优于2个数量级(3~140 eV)。若该TOF质量分析器与短瞬高压脉冲放电离子源耦合联用,可广泛应用于高能离子束的快速检测,如真空阴极放电对制备薄膜、离子注入材料的表征,导电材料的离子电荷态分布以及离子扩散速度的测定等。     

飞行时间质谱仪传输区射频电源的研制

设计了一种新型射频电源,主要由信号发生及放大模块、幅值调节模块、功率驱动模块构成,其结构紧凑、体积小、性能稳定、成本低。此射频电源分为低频和高频两部分,分别用以驱动自制飞行时间质谱仪传输区的两段四极杆,可调频率范围分别为150～900 kHz及1～2 MHz,峰峰值Vp-p可调范围分别为0～100 V和0～1 400 V。配合自制飞行时间质谱仪对实际样品进行测试,可稳定测得m/z 50～1 200范围内的离子,5.0×10-9～5.0×10-5mol/L浓度的样品离子线性良好。     

常见毒品离子阱飞行时间质谱分析手册

正本书重点阐述了离子阱飞行时间质谱(LCMS-IT-TOF)在毒品鉴定方面的应用,详细介绍了利用离子阱飞行时间质谱仪对49种毒品样品进行多级质谱分析的谱图,总结其裂解途径。每种样品包含了其基本的信息,如名称、分子式、结构式、CAS登记号、分子量、熔点、沸点、性状等等,以及各种质谱条件下的     

N4+的生成与检测

用从Nd:YAG激光器发出的波长532nm的激光(能量约为10mJ/pulse)溅射由BN、ZrN粉末分别压成的直径13mm、厚度约2～5mm的固体压片样品,生成了含氮团簇N4+。实验中,用高纯氮气为载气,辅助含氮团簇的生成并冷却激光溅射所产生的团簇。反射式飞行时间质谱仪监测反应过程证实N4+的存在,且其存在时间超过200μs。     

全二维气相色谱–飞行时间质谱法分析环境样品中短链氯化石蜡的方法

本发明公开了一种全二维气相色谱–飞行时间质谱法分析环境样品中短链氯化石蜡的方法,属于分析测试技术领域。该方法包括如下步骤:(1)环境样品中SCCPs的富集提取;(2)采用全二维气相色谱电子轰击电离源低分辨飞行时间质谱仪检测;(3)采用谱库检索和保留时间指数对样品中SCCPs组分定性;(4)采用内标标准曲线法测定样品中SCCPs总量。所用前处理方法萃取效率高,净化效果好,适用范围广;所用仪器分析效率高,分离效果好,抗干扰能力强;定性方法快速、准确,可不依赖于标准物质;定量方法检出限低,灵敏度高,线性范围宽,重复性好,可满足实际环境样品中SCCPs的分析要求。     

气溶胶单粒子化学成分的实时测量

自行设计了国内第一台可实时测量气溶胶单粒子化学成分的气溶胶飞行时间质谱仪,并用该仪器对两类燃烧过程产生的气溶胶粒子进行了实时测量。实验结果展示了本仪器能够同时实现实时在线测量和单粒子检测,从而克服了传统的离线检测方法如色谱法、化学方法的局限性。     

MALDI-TOF-MS测定溶菌酶的相对分子质量中在线纯化技术的应用

用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)测定溶菌酶的相对分子质量,采用硝酸纤维素膜作为溶菌酶的固相载体,在质谱仪上进行在线纯化溶菌酶样品,在测试前尽可能除去样品中的添加剂,以消除一些盐和蛋白质变性剂抑制样品峰的情形;此法简单、快速,并可明显增强离子峰的强度,提高测试的灵敏度。     

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.     

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.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

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^-。     

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.