Analytical Instrument Documents

By gradual heating, unlike Py/GC/MS, moderately fragmented oligomer components can be analyzed by DART-MS. Some of the oligomer components generated include the end group structure by single cleavage of the main chain, which helps to analyze the structure of the polymer. Here, an analysis example of polyphenylene sulfide (PPS) using TDP-DART-MS is reported [2]. PPS is an engineering plastic with excellent heat resistance and chemical resistance. It is important to analyze the structure of the end groups because the difference in the manufacturing method appears in the end groups. However, it was difficult to analyze the end groups of PPS because it is insoluble in general organic solvents.

In this report, we verify that the end group analysis of polystyrene by TDP-DART-MS examined in Reference [1] is possible by the TDP device ionRocket (BioChromato) and AccuTOF™ LC-plus 4G.

We report an application related to synthetic compound confirmation that combines nuclear magnetic resonance (NMR), which is indispensable for structural analysis of organic compounds, and mass spectrometry by DART.

Dr. Furuta of Kyushu University has been studying membrane transport of proton and specific anions using porphyrin compounds. He has reported that multiple N-confused expanded porphyrin, which combines rotating and expanding characteristics of intramolecular pyrrole ring in N-confused porphyrin (NCP), an isomer of porphyrin, is effective for membrane transport.

In 2003 JEOL announced the JMS-T100CS AccuTOF CS, incorporating a new ion source designed to support cold-spray ionization. The new ion source features a retractable flow redirector designed to switch the direction of spray between vertical and coaxial. We analyzed proline in an AccuTOF CS, studying the effect of the retractable flow redirector.

Foundation is one of the essential cosmetics for women. At the mean time, it often makes a stain on clothing. We directly analyzed foundation stains on cloth (Fig. 1) without sample preparation by using DART (Direct Analysis in Real Time) ion source installed on AccuTOF™ LC series. Foundation from 3 manufacturers were measured and compared.

The AccuTOF makes it very easy to obtain exact mass measurements and determine elemental compositions. The mass spectra shown below were acquired with the electrospray ion source operated in negative-ion mode. The mass calibration was acquired the previous day in positive-ion mode. After changing the mass spectrometer polarity and retuning, a stearic acid impurity (present in the methanol) was used as a single-point drift correction “lock mass” to determine the elemental composition of the analyte peak at m/z 256.06242 and the palmitic acid impurity at m/z 256.23104. The error was less than 0.002 u.

JEOL recently introduced a new-generation LC/TOFMS system (the “AccuTOF™”)with a wider dynamic range than conventional LC-TOF MS systems. The increased dynamic range of the AccuTOF provides qualitative and quantitative analysis with the increased accuracy and resolution of an LC/TOFMS system. While the AccuTOF preserves the benefits of TOF MS, such as high sensitivity, high resolution and high mass accuracy, it also features a durable orthogonal API source with long-term stability and easy maintenance. Here, we describe the features of the orthogonal API source. We also demonstrate the ability to operate the AccuTOF for an extended period in the presence of a nonvolatile phosphate buffer often used for LC Analysis.

Sudan dyes are red dyes that are used for coloring solvents, oils, waxes, petrol, and shoe and floor polishes. They are considered to be carcinogens and teratogens. Due to this fact, the US and the EU do not permit the use of these colors as food additives. However, in some countries, these dyes are still occasionally used in order to intensify the color of bell pepper and chili powders. Here, we describe a simple LC/TOF-MS method for sudan dyes I, II, III, and IV analysis.

It has been a decade since Dodonov and his colleagues [1] first announced the electrospray ionization time-of-flight mass spectrometer (ESI-TOF MS). Their initial findings have been enhanced by Standing and others [2,][ 3], and it has been recently reported that a large TOF MS system achieved a mass resolution exceeding 10,000 [4]. Encouraged by the results acquired by Dodonov and Standing, some of the MS manufactures have produced bench top ESI-TOF MS systems. However, most of these commercial models have a narrow dynamic range and are unfit to quantitative analysis because they use a TDC (Time-to-Digital Converter) as a data acquisition system. Their applications were mainly in qualitative analysis with exact mass measurement, and are limited in such fields as environmental studies and chemical dynamics that require only qualitative analysis. Because of detector saturation, these systems only show good mass acuracy when operated within a limited analyte concentration range.