Analytical Instrument Documents

The AccuTOF GCv 4G is JEOL's third generation high resolution GC-TOFMS. New, enhanced features of the system include: 1) Recording speed: up to 50 spectra/sec 2) Mass resolution: 8,000 or more (m/z 614, FWHM) 3) Mass accuracy: 1.5 mmu or 4 ppm 4) Mass range: m/z 4 to 5,000 Comprehensive 2D GC (GCxGC) is a chromatographic separations technique that uses 2 columns with different polarities arranged in a series. Featuring higher resolution than conventional capillary GC analysis, it is a powerful tool for the measurement of multiple components in a complex mixture. However, because there is a cryo-trap before the 2nd column, the resulting peaks in the chromatograms are extremely narrow. As a result, the system requires a detector capable of high speed data recording. The TOFMS is an ideal detector for the 2D GC system. In this work, we analyzed aroma oil using a GCxGCHRTOFMS system, in which the AccuTOF GCv 4G was used with a Zoex GCxGC system to examine the spectrum recording speed and mass accuracy.

Skin is an active metabolic tissue that synthesizes a variety of complex lipid compounds. Sebum, an oily material secreted by the skin, is known to provide a moisturizing effect, sunlight protection, and antibacterial protection for the skin surface. Sebum consists of a complex mixture of free fatty acids, squalene, cholesterol, wax esters, diacylglycerols and triacylglycerols. These species and their concentrations vary depending on skin conditions. Lipid compounds are generally measured by using GC–FID, GC–MS or LC–MS. However, these methods are often unable to separate all of the individual compounds under the same measurement conditions. In addition, it can be difficult to definitively identify each lipid compound due to co-elution. On the other hand, two-dimensional GC - high resolution time-of-flight mass spectrometry (GCxGC–HRTOFMS) is a powerful tool for identifying analytes in complex mixtures such as crude oils. The purpose of this work is the comprehensive detection and identification of lipid compounds in sebum by using GCxGC-HRTOFMS.

Perfumes are known to be complex mixtures that typically contain a variety of compounds. Their scents are strongly affected by these compounds and their quantity ratios. Additionally, these ratios can change over time, thus changing the perfume’s scent. Two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC-TOFMS) is an effective technique for measuring complex samples like perfumes. Using electron ionization (EI) allows for database searches. However, these searches may result in mis-assignments without the additional high-resolution molecular ion information that can be generated through soft ionization techniques. In this study, we used GCxGC-HRTOFMS with EI and the soft ionization techniques of FI (Field Ionization) and PI (Photoionization). Additionally, we measured the changes in intensity over time for the top note/middle note/base note compounds.

Comprehensive two-dimensional gas chromatography (GCxGC) in combination with high-resolution mass spectrometry (HRMS) is a powerful tool for the analysis of complex mixtures. However, new software tools are required to facilitate the interpretation of the rich information content in GCxGC/HRMS data sets. In this work, we analyzed a dust sample collected from an electronics recycling facility by using GCxGC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. Nontraditional Kendrick Mass Defect (KMD) plots were used to identify halogenated contaminants in an electronics waste sample. Database search results combined with elemental composition determinations from exact-mass data were used to identify (potential) persistent organic pollutants (POPs).

Comprehensive two-dimensional gas chromatography (GC×GC) is a kind of continuous heart-cut GC system. Two different types of columns are connected via a modulator in the same GC oven. By using the two columns together, this technique provides very high separation capabilities when compared to one- dimensional GC analysis. This report shows the difference of separation result for diesel oil when 2 different sets of combined columns are used with GC×GC-HRTOFMS (FI).