Analytical Instrument Documents

The structural characterization of copolymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) remains a challenging task, since their random comonomer distribution creates very complicated mass spectra. In this study, a high-resolution TOF mass spectrometer with a spiral ion trajectory was applied to the structural and compositional characterization of free radical copolymerized poly(methyl methacrylate-co-tert-butyl methacrylate), poly(MMA-co-tBMA)s in ethyl lactate acting as a chain transfer agent. Virtually complete peak assignments of the isobaric components within the poly(MMA-co-tBMA)s served to identify the end-group combinations and copolymer compositions of individual copolymer components, allowing the distributions of comonomer compositions and six types of end-group combinations to be evaluated.

Last Updated: September 2013

PaperSpray Principle: Samples and a polar solvent such as methanol are deposited onto a porous substrate such as filter paper or chromatography paper cut into a triangle. When a high voltage (typically ~3000V) is applied, Electrospray Ionization (ESI) occurs at the tip of the paper triangle. PaperSpray is simpler than ESI and does not require a pump, spray needle, desolvating gas or precise alignment.

The JMS-TQ4000GC Triple-Quadrupole Mass Spectrometer accurately measures trace or residual pesticides in agricultural materials, trace levels of regulated chemicals in tap water, and simplifies quantitative analysis of persistent environmental pollutants such as dioxins and PCB’s.

The new JMS-Q1600GC UltraQuad™ SQ-Zeta Single Quad Mass Spectrometer of JEOL is our 6th generation high-end Gas Chromatograph Quadrupole Mass Spectrometer.

Different ionization methods for MS applications: Electron Ionization (EI), Chemical Ionization (CI), Photo Ionization (PI), Field Ionization / Field Desorption (FI/FD) Electrospray Ionization (ESI ), CSI (Cold-Spray Ionization), Direct Analysis in Real Time (DART), and Matrix Assisted Laser Desorption / Ionization (MALDI).

JEOL, a world leader in SEM technology for six decades, offers scanning electron microscopes that enable imaging and analysis of the smallest details in forensic microscopy. JEOL SEMs are used for crime scene investigation, accident reconstruction, ballistics, explosives detection, toxicology, arson investigation, automated gun shot residue analysis, trace evidence, and failure analysis. The imaging and analytical ability of JEOL SEMs reveal physical and chemical evidence that might otherwise be easily overlooked.

JEOL introduced the DART ion source in 2005, and the technology quickly gained recognition, winning both the Pittcon Editor’s Gold Award and the R&D 100 Award. Since that time nearly 400 papers have been published by chemists using the AccuTOF-DART. The introduction of DART made it possible for the first time to carry out atmospheric pressure ionization for analysis of samples in open air.

In many fields such as clinical diagnosis and food inspection, there is a demand for rapid, reliable and simple-to-use methods for characterizing bacteria. This paper explores the use of two new and innovative instruments called ClairScope™ and SpiralTOF™ for this rapid characterization. The JASM-6200 ClairScope™ integrates an optical microscope (OM) with a scanning electron microscope (SEM) where it is possible to observe samples in solution, in an open system, by the SEM at atmospheric pressure. This type of sample would typically require extensive sample pretreatment that would take a day or more with conventional SEM techniques. With the recently developed ClairScope™, fine morphological observation can be performed directly in solution with simple sample pretreatment of one hour or less. The JMS-S3000 SpiralTOF™, is a matrix-assisted laser desorption/ionization mass spectrometer (MALDI-MS) with a spiral ion trajectory. With sample pretreatment as fast as a few minutes, the SpiralTOF™ can characterize ribosomal proteins and phospholipids with high accuracy. Ribosomal proteins are biomarkers for phylogenetic classification, and phospholipids are used for chemotaxonomic analysis. The combination of ClairScope™ and SpiralTOF™ are found to be powerful instruments for the characterization of bacteria.

A gas-chromatograph mass spectrometer (GC-MS) is a combined analyzer that has superior ability in analyzing organic compounds qualitatively and quantitatively. The first part, gas chromatograph, separates the compounds included in a sample (mixture), then the second part, mass spectrometer, obtains mass spectra of the compounds to carry out qualitative analysis. Quantitative analysis can be carried out as well from the peak area of the mass chromatogram of the compound. As a mass spectrometer of a GC-MS system, several types of mass spectrometers are on the market, such as magnetic field, quadrupole (QMS), ion trap (ITD), and time-of-flight (TOF). Each mass spectrometer has its own features and applications.