High-resolution ion mobility separations coupled to mass spectrometry: What's next?

Herein, I provide a personal perspective on high-resolution multipass ion mobility spectrometry-mass spectrometry (IMS-MS), with a specific emphasis on cyclic (cIMS) and structures for lossless ion manipulations (SLIM IMS)-based separations. My overarching goal for this perspective was to detail what I believe will be the key important areas in which IMS-MS will help shape the bioanalytical community and especially omics-based research.     

Morphological biosignatures from relict fossilised sedimentary geological specimens: a Raman spectroscopic study

Morphological biosignatures (features related to life) and associated terrestrial sedimentary structures that provide possible sampling targets for the remote astrobiological exploration of planets have been analysed using Raman spectroscopic techniques. The spectral data from a suite of samples comprising crypto‐chasmoendoliths, preserved microbial filaments and relict sedimentary structures comprise a preliminary database for the establishment of key Raman biosignatures. This will form the basis for the evaluation of prototype miniaturised instrumentation for the proposed ESA ExoMars mission scheduled for 2013. The Raman spectral biosignatures of carotenoids and scytonemin, organic biomolecules characteristic of the cyanobacterial colonisation of geological matrices and biogeologically modified minerals are also identifiable in the sedimentary specimen materials. The results of this study demonstrate the basis of the molecular recognition of extinct and extant exobiology that will feed into the elemental structural analyses of morphological structures provided by associated SEM, XRD and laser‐induced breakdown spectroscopy (LIBS) techniques on robotic analytical landers. Copyright © 2007 John Wiley & Sons, Ltd.     

基于平方根UKF滤波的轨道机动飞行器自主导航方法

在利用SINS／GPS对轨道机动飞行器进行自主导航的过程中,为提高轨导航精度,将惯导工具误差作为状态变量进行估计,同时考虑了杆臂偏差对导航精度的影响,将GPS卫星的星历误差、对流层误差视为一阶马尔科夫过程,用Allan方差的方法建立了GPS接收机的误差模型。为保证滤波过程中协方差阵的正定性,提高计算精度和速度,应用平方根UKF滤波方法进行轨道机动飞行器自主导航,仿真结果验证了所给出方法的可行性和有效性。     

Low-cost and versatile analytical tool with purpose-made capillary electrophoresis coupled to contactless conductivity detection: Application to antibiotics quality control in Vietnam

In this study, the development of our purpose-made capacitively coupled contactless conductivity detection (C⁴D) for CE is reported. These systems have been employed as a simple, versatile, and cost-effective analytical tool. CE-C⁴D devices, whose principle is based on the control of the ion movements under an electrical field, can be constructed even with a modest financial budget and limited infrastructure. A featured application was developed for quality control of antimicrobial drugs using CE-C⁴D, with most recent work on determination of aminoglycoside and glycopeptide antibiotics being communicated. For aminoglycosides, the development of CE-C⁴D methods was adapted to two categories. The first one includes drugs (liquid or powder form) for intravenous injection, containing either amikacin, streptomycin, kanamycin A, or kanamycin B. The second one covers drugs for eye drops (liquid or ointment form), containing either neomycin, tobramycin, or polymyxin. The CE-C⁴D method development was also made for determination of some popular glycopeptide antibiotics in Vietnam, including vancomycin and teicoplanin. The best detection limit achieved using the developed CE-C⁴D methods was 0.5 mg/L. Good agreement between results from CE-C⁴D and the confirmation method (HPLC- Photometric Diode Array ) was achieved, with their result deviations less than 8% and 13% for aminoglycoside and glycopeptide antibiotics, respectively.     

南极中山站周边水环境冰情监测系统的设计与研究

系统实现对南极中山站周边冰、水环境的长期连续实时监测,可以为分析南极环境变化是否对全球气候异常变化造成影响提供最基本的科学数据.利用空气,冰与水介质的电导率不同的原理用微控制器控制冰情检测传感器来实现冰水环境的自动化监测,设计了可以实现冰厚度、水深度、温度的定点连续冰情监测系统,监测数据可以存储在系统内嵌的SD存储卡中,方便观测人员进行调用.通过卫星实现数据无线传输.     

Raman spectroscopy with LED excitation source

We propose and experimentally demonstrate a novel instrument arrangement, which allows for the collection of Raman spectra with a broadband light source. This is achieved by spatially dispersing the optical spectrum in the focal plane and confocally reimaging the Raman signal, which originates from different locations, onto the entrance slit of an imaging spectrometer. Using this approach and broadband radiation derived from a commercially available LED, we acquired high signal‐to‐noise spectra with a spectral resolution limited by the spectral resolution of a spectrometer. Copyright © 2013 John Wiley & Sons, Ltd.     

Summary of ISO/TC 201 Standard: ISO 18115‐2:2010 – Surface chemical analysis – Vocabulary—Terms used in scanning probe microscopy

This International Standard revises ISO 18115:2001 and the two subsequent amendments by bringing the material up to date and by separating the general terms and terms used in spectroscopy into Part 1 and terms relating to scanning probe microscopy into Part 2. This part, Part 2, covers 227 terms used in scanning probe microscopy as well as 86 acronyms. The terms cover words or phrases used in describing the samples, instruments and theoretical concepts involved in surface chemical analysis. Copyright © 2012 Crown copyright.     

Ion trap mass analysis at high pressure: an experimental characterization

In recent years, it has become increasingly interesting to understand the performance of mass spectrometers at pressures much higher than those employed with conventional operating conditions. This interest has been driven by several influences, including demand for the development of reduced‐power miniature mass spectrometers, desire for improved ion transfer into and through mass spectrometers, enhanced‐yield preparative mass separations, and mass filtering at the atmospheric pressure interface. In this study, an instrument was configured to allow for the performance characterization of a rectilinear ion trap (RIT) at pressures up to 50 mtorr with air used as the buffer gas. The mass analysis efficiency, mass resolution, isolation efficiency, and collision‐induced dissociation (CID) efficiency were evaluated at pressures ranging from 1 to 50 mtorr. The extent of degradation of mass resolution, isolation efficiency and ion stability as functions of pressure were characterized. Also, the optimal resonance ejection conditions were obtained at various pressures. Operations at 50 mtorr demonstrated improved CID efficiency in addition to peak widths of 2 and 5 m/z units (full width at half‐maximum, FWHM) for protonated caffeine (m/z 195) and Ultramark (m/z 1521) respectively. Copyright © 2009 John Wiley & Sons, Ltd.     

Tubing modifications for countercurrent chromatography: Investigation of geometrical parameters

Countercurrent chromatography (CCC) is a separation technique which may be described as a combination of a great number of liquid–liquid distributions of analytes in a two-phase solvent system with liquid chromatography (LC) features. Even optimized CCC separations currently provide a lower number of theoretical plates when compared to LC. For this reason, instrumental advancements are indispensable to, at least partly, overcome this drawback. Recently, we found that improvement of the classic CCC coil, that is using a long hollow tubing, may be achieved by the introduction of tubing crimpings which increase the stationary phase retention. In this study, we systematically investigated the effects of three geometrical parameters (crimping depth, distance between two crimpings as well as partial or complete crimping of the tubing) on the stationary phase retention by a factorial design of experiments approach. Separation efficiency tests were performed with two groups of analytes: fatty acid methyl esters (FAME) in the n-hexane/acetonitrile (HAcn) and alkyl p-hydroxybenzoates in the n-hexane/tert-butylmethylether/methanol/water solvent system. The most narrow crimping distance and the deepest crimping of the tubing were the best configurations in the examined flow rate range.     

An alternative approach for charge decay measurement to assess the suitability of materials

A method of charge decay testing is proposed in which a localized electric field is applied by a fieldmeter to an area of the material to be tested. The variation of electric field is recorded as charge migrates across the surface. Arrangements are described for this method of testing and studies reported comparing results with corona and tribocharge decay measurements. Interesting differences are shown between the methods of testing.Induction charge decay testing is not proposed as a replacement for corona or tribocharge decay testing. It offers the opportunity for simpler instrumentation and measurement of faster charge decay times.