离子色谱法测定污水中阴、阳离子的前处理

研究了离子色谱技术在污水中常见阴、阳离子监测方面的应用。根据大量实验数据提出了水样前处理方法，确定了色谱条件。污水样品经前处理后，阴离子测定结果的相对标准偏差为0.71%-4.4%，回收率为94．6％－108.6%。     

阀切换在化肥分析专用多通道全自动气相色谱仪中的应用

阐述了阀切换在化肥专用多通道气相色谱仪中的原理、硬件、软件、流程和色谱图。现场使用表明,利用微机控制阀切换进行多点采样进样分析,能减少手动进样与人工处理数据的误差。     

虚拟仿真软件辅助液相色谱分离条件的绿色优化实验

由于耗时长、废液多等制约因素，大学高效液相色谱(HPLC)实验均未涉及分离条件的优化，实验中学生只是“照方抓药”完成操作练习，其面向特定分离对象构建HPLC分析方案的实践能力并未得到有效培养。为此，我们提出一种改进方案：将色谱进样练习和大黄蒽醌类化合物的检测实验有机结合起来，在不延长学时的前提下，采用虚拟仿真软件HPLC Simulator进行色谱条件优化。学生在进样练习实验中通过分工协作获取不同温度、不同流动相配比条件下的保留时间数据；在全体同学共享实验数据的基础上，利用HPLC Simulator软件实现色谱分离条件的绿色优化。软件模拟输出的最优色谱条件在第二次课上得到实验验证。这种改进措施将原本枯燥无味的色谱进样练习升华为探索性的实验，激发了学生的学习热情。可使学生在有限的学时内掌握色谱条件的优化方法，培养学生利用信息技术解决实际问题的能力，提高信息化背景下的实验教学质量。另外，通过分工协作数据共享可以更好地培养学生的团队合作精神。     

静态箱法气相色谱法自动检测农田N2O排放

Ｎ２Ｏ自动观测系统由微机控制电路和气路，使采样箱、气相色谱仪（ＧＣ）和积分仪自动工作，系统可连续采样分析，自动存储色谱数据，并可同时测定存储温度和辐射等气象数据，系统从放置于田间可自动开关箱盖的采样箱中，依次抽取空气样品，经除水、ＣＯ２处理后送入气相色谱仪分析Ｎ２Ｏ浓度，箱中浓度随时间的变化计算Ｎ２Ｏ的排放通量。     

高效液相色谱—电感耦合等离子体发射光谱联用的瞬时信号采集和处…

本文对高效液相色液相色谱－电感耦合等离子体原子发射光谱联用技术进行了研究。对所用ＩＣＡＰ－９０００型等离子体原子发射光谱仪的控制采样程序进行了部分修改，采集的数据通过异步串行通讯方式由ＡｐｐｌｅⅡ微机传送至ＩＢＭＰＣ２８６机进行处理。发展的时信号３采集程序能满足ＨＰＬＣ的检测要求，并净这一联用技术成功的用于砷的形态分析。     

微机控制动态配气装置的研究

按照ISO6145标准，设计，研制了微机控制动态配气装置，实现了微机对动态配气装置主要动态参数的实时监控，存储和结果处理，将该动态配气装置与静态容量法配气装置进行了比较，两种方法配制的标准气体的量值一致，对动态法配气的量值不确定度进行了评定。     

微计算机联机的毛细管等速电泳数据采集、处理系统的研制

现有的商品化毛细管等速电泳仪有的已配有微机控制单元,以实现对部分实验条件和步骤的控制以及数据自动采集和处理等。由于直流电导检测器的检测电极直接与电解液接触,悬浮工作于相当高的电压上,因而通常采用的方法是将检测器测得的电压信号先经电压频率转换后,利用光电耦合来实现测量系统与电泳分离系统的高压隔离,现有文献报道及商品化的等速电泳仪的联机系统中采用ADC(模拟     

中兽药口服液中非法添加化学药物高分辨质谱筛查

建立了适用于中兽药口服液中167种非法添加化学药物的超高效液相色谱-四极杆静电场轨道阱质谱高通量筛查方法。样品采用0.5%甲酸乙腈-水进行振荡超声提取，电喷雾电离源（ESI）、正负离子同时扫描方式进行数据采集。通过与自建的167种化合物的基本信息及色谱-质谱信息数据库进行比对，对色谱-质谱条件、提取溶剂的种类和净化条件进行优化。将经前处理后的口服液样品上机测试后，采用Trace Finder筛查软件对数据结果进行分析。结果显示，50 ng/mL非法添加药物（头孢类和内酰胺类药物为100～200 ng/mL）上机时可定性检出。不同药物配方因基质影响，其非法添加药物的检出率略有差异。该方法可基本实现中兽药口服液中非法添加化学药物的高通量快速筛查，具备操作简便、快速高效的特点，为其他兽药剂型中非法添加药物的筛查奠定了基础。     

微机上分子实体模型的实现

本文采用简单、快速的方法在微机上实现光照与明暗处理的分子实体模型，并给出了明暗层次丰富的分子柱状模型、球柱模型和ＣＰＫ模型的显示实例。     

一维1H同核选择性激发核磁共振方法在混合物分析中的应用

在无需复杂样品前处理、无色谱分离的条件下，一维¹H同核选择性激发核磁共振技术可对复杂混合物样品实现无损、高效、灵敏的分析。本文综述了不同的一维同核选择性激发方法，根据各方法脉冲序列组成的复杂程度，分为基本和组合两大类。介绍了各方法的基本原理、特点与应用，并总结了它们在混合物分析中的应用价值。     

2D WIN-NMR: BRUKER's PC-based display and processing package for 2D NMR data matrices

Summary Off-line retrieval and processing of data is a considerable advantage of a computer used separately from the spectrometer. 2D WIN-NMR — BRUKER's PC based display and processing package for 2D NMR data matrices — has been designed to fulfill two particular criteria: a variety of different display options allow an interactive interpretation of the 2D data and the best graphical document can be created at the end of the working session. This is accomplished making extensive use of WINDOWS based data transfer capability. For analyzing data separate from the spectrometer it is also necessary to be able to process 2D NMR datasets. 2D WIN-NMR includes all of the standard processing functions an NMR spectroscopist needs and is an easy-to-handle tool for scientific work.     

Mass spectrometric analysis of high-purity helium and hydrogen, using a dynamic sampling and calibration system

A dynamic gas sampling system has been designed for use with a mass spectrometer (A.E.I. Model MS2G). It is capable of sampling directly from gas streams at pressures in the region of 800 torr and has been satisfactorily used for the analysis of high-purity helium and hydrogen containing less than 50 vpm total impurity. The overall sensitivity is 1 vpm or better. The design permits the mass spectrometer to be used with its normal gas sampling system when required. A dynamic gas blending rig, incorporating a recirculation and purification system, has been developed for the calibration of the mass spectrometer over the range 5-100 vpm of impurity content.     

Networking Mass Spectrometer Data Systems for Improved Productivity and Electronic Archiving of Data

Several Finngan-MAT mass spectrometer data systems were networked together to achieve the following two primary objectives: (1) to allow access to mass spectrometry data and data processing functions from remote locations without affecting simultaneous data acquisition at the instruments, and (2) to electronically archive mass spectrometry data at a central location on a high-capacity, fast-access device that allows rapid retrieval of archived data for all data processing operations at all locations. UNIX workstations, IBM PC/AT-compatible computers, and Data General Nova minicomputers were connected via Ethernet interfaces to allow rapid data transfer among all systems as well as X-Windows access to UNIX-based systems. Bridging techniques were used to isolate possible high-traffic areas of the network and to enable security measures for adequate protection of files. Additionally, serial connections were made through a Northern Telecom phone system to provide remote terminal access to the Data General Nova-based systems. Use of these connectivity techniques significantly improved productivity by allowing retrieval, processing, and printing of data from remote locations, such as office areas, without affecting data acquisition, processing, and printing performed simultaneously at the instruments. For archival purposes, data files are electronically stored on high-capacity magneto-optical disks for rapid retrieval. A highcapacity fixed disk is also available for centralized temporary data file storage. A Digital Equipment Corporation DECstation 2100 UNIX workstation was used as the file server for centralized data storage while being simultaneously utilized as the data system computer for one of the mass spectrometers. Utilization of this UNIX-based file server system in conjunction with Ethernet connectivity techniques provides a centralized, rapid-access, high-capacity, cost- and space-efficient method for electronic archival of mass spectrometry raw data recorded at all of the instruments.     

Evaluation of a surface-sampling probe electrospray mass spectrometry system for the analysis of surface-deposited and affinity-captured proteins

A combined self-aspirating electrospray emitter/surfacing-sampling probe coupled with an ion trap mass spectrometer was used to sample and mass analyze proteins from surfaces. The sampling probe mass spectrometer system was used to sample and detect lysozyme that had been deposited onto a glass slide using a piezoelectric spotter or murine gamma-interferon affinity captured on a glass slide using surface-immobilized anti-gamma-interferon antibody. The detection level for surface-deposited lysozyme (spot size < or =200 microm) was approximately 1.0 fmol (approximately 100 fmol/mm2) as determined from the ability to measure accurately the protein molecular mass from the mass spectrum acquired by sampling the deposit. These detection limits may be sufficient for certain applications in which protein fractions from a separation method are collected onto a surface. Radiolabeled proteins were used to quantify the surface density of immobilized antibody and the efficiency of capture of the gamma-interferon on glass and higher surface area ceramic supports. The capture density of gamma-interferon at surface saturation ranged from about 23 to 50 fmol/mm2 depending on the capture surface. Nonetheless, mass spectrometric detection of affinity capture protein was successful in some cases, but the results were not reproducible. Thus, improvement of the sampling system, ionization efficiency and/or capture density will be necessary for practical sampling of affinity-captured proteins. The means to accomplish improved sampling system detection limits and to increase the absolute amounts of protein captured per unit area are discussed.     

Thermal reactions by automated mass spectrometric thermal analysis

Combination of differential thermal analysis (DTA) with time-of-flight mass spectrometry and data storage on magnetic tape is used to study thermal decompositions.A modified Du Pont 900 DTA cell is used for reactions at atmospheric pressure with evolved gas sampling into a small time-of-flight spectrometer.For fast reactions a specially developed DTA cell is operated within the mass spectrometer and operates at high vacuum.A combination of both operational modes yields pressure dependencies of chemical decomposition.Examples studied include inorganic compounds and complexes, organometallics and organic chemicals such as fire retardants.The data are presented as intensity/temperature curves for each observed fragment, which not only yields decomposition temperatures but also—by the curve shapes—information on the mode of decomposition.     

MSE with mass defect filtering for in vitro and in vivo metabolite identification

Metabolite identification studies involve the detection and structural characterization of the biotransformation products of drug candidates. These experiments are necessary throughout the drug discovery and development process. The use of high-resolution chromatography and high-resolution mass spectrometry together with data processing using mass defect filtering is described for in vitro and in vivo metabolite identification studies. Data collection was done using UPLC coupled with an orthogonal hybrid quadrupole time-of-flight mass spectrometer. This experimental approach enabled the use of MS(E) data collection (where E represents collision energy) which has previously been shown to be a powerful approach for metabolite identification studies. Post-acquisition processing with a prototype mass defect filtering program was used to eliminate endogenous interferences in the study samples, greatly enhancing the discovery of metabolites. The ease of this approach is illustrated by results showing the detection and structural characterization of metabolites in plasma from a preclinical rat pharmacokinetic study.     

小型高分辨电子轰击离子源反射式飞行时间质谱仪的研制

常用的气体分析质谱仪使用四极杆质谱作为分析器,分辨率一般低于300,无法解决同质量数离子带来的干扰问题.本实验自行研制了一种小型高分辨气体分析质谱仪,它采用电子轰击离子源反射式飞行时间质量分析器.仪器腔体总长45 cm,在m/z 28的位置,质量分辨率达到3000(Full width at half maximum,FWHM),实现了CO和N2的半峰谷分离;在m/z 69的位置,仪器分辨率达到5000(FWHM).在直接大气压进样条件下,可以检测到空气中136Xe(含量7.8 μ g/m3)和80Kr(含量2.8 μg/m3).使用ADC采集时,仪器的动态范围为1 06.该仪器将作为高端气体质谱仪,应用于过程监测在线分析、环境有机挥发物研究、热分析质谱及催化反应监测等领域.     

Rapid multivariate analysis of 3D ToF‐SIMS data: graphical processor units (GPUs) and low‐discrepancy subsampling for large‐scale principal component analysis

Principal component analysis (PCA) and other multivariate analysis methods have been used increasingly to analyse and understand depth‐profiles in XPS, AES and SIMS. For large images or three‐dimensional (3D) imaging depth‐profiles, PCA has been difficult to apply until now simply because of the size of the matrices of data involved. In a recent paper, we described two algorithms, random vector 1 (RV1) and random vector 2 (RV2), that improve the speed of PCA and allow datasets of unlimited size, respectively. In this paper, we now apply the RV2 algorithm to perform PCA on full 3D time‐of‐flight SIMS data for the first time without subsampling. The dataset we process in this way is a 128 × 128 pixel depth‐profile of 120 layers, each voxel having a 70 439 value mass spectrum associated with it. This forms over a terabyte of data when uncompressed and took 27 h to process using the RV2 algorithm using a conventional windows desktop personal computer (PC). While full PCA (e.g. using RV2) is to be preferred for final reports or publications, a much more rapid method is needed during analysis sessions to inform decisions on the next analytical step. We have therefore implemented the RV1 algorithm on a PC having a graphical processor unit (GPU) card containing 2880 individual processor cores. This increases the speed of calculation by a factor of around 4.1 compared with what is possible using a fast commercially available desktop PC having central processing units alone, and full PCA is performed in less than 7 s. The size of the dataset that can be processed in this way is limited by the size of the memory on the GPU card. This is typically sufficient for two‐dimensional images but not 3D depth‐profiles without sampling. We have therefore examined efficient sampling schemes that allow a good approximate solution to the PCA problem for large 3D datasets. We find that low‐discrepancy series such as Sobol series sampling gives more rapid convergence than random sampling, and we recommend such methods for routine use. Using the GPU and low‐discrepancy series together, we anticipate that any time‐of‐flight SIMS dataset, of whatever size, can be efficiently and accurately processed into PCA components in a maximum of around 10 s using a commercial PC with a widely available GPU card, although the longer RV2 approach is still to be preferred for the presentation of final results, such as in published papers. Copyright © 2016 The Authors Surface and Interface Analysis Published by John Wiley & Sons Ltd     

Rapid and selective identification of molecular species in phosphatidylcholine and sphingomyelin by conditional neutral loss scanning and MS3

Analyses of molecular species of phospholipids containing choline (Ch), such as phosphatidylcholine (PC) and sphingomyelin (SM), are reported. Neutral loss scanning was applied for the selective detection of these lipids using a quadrupole-linear ion trap mass spectrometer. By using ammonium formate as an elution buffer, both PC and SM were detected as [M+HCOO]- ions in the negative ion mode. Upon collisional activation, the [M+HCOO]- adduct ions underwent facile elimination of HCO2, to yield an ion which, in turn, readily underwent collisional-induced dissociation (CID) to eliminate CH3 to yield an [M-CH3]- ion. By selecting the proper conditions for scanning for neutral loss of 60 Da (HCO2+CH3), SM species were identified separately from PCs. Further, by selection of this [M-CH3]- ion as the precursor ion, the identities of the fatty acyl chains of PC species can be effectively obtained by MS3 experiments. Furthermore, by the MS3 analyses of [M-CH3]- specifically obtained from SM molecules, identification of sphingosine or sphinganine derivatives and their N-acyl species can also be effectively obtained. This systematic analysis of PCs and SMs by conditional neutral loss scanning, with subsequent analyses by MS3, using a linear ion trap mass spectrometer in the negative ion mode, appears to be a very effective and sensitive method. Further, MS/MS in the positive ion mode at relatively low collision energy was also effective for the identification of positional specificities in individual molecular PC species from their lysoPC-related fragments. The present paper deals only with qualitative identification of individual molecular species, and the related quantitative studies are now underway.