The AccuTOF-GCv|4G from JEOL features a high sensitivity (SN >100 at OFN 1 pg/uL) for a time-of-flight GCMS system. High resolution and mass accuracy allow for rapid elemental composition determination and target compound identification. The TOF unit acquires up to 50 averaged spectra/sec with mass resolving power of 8000 FWHM and high-mass accuracy, and is compatible with commercially available 2D GC systems for GCxGC/EI and GCxGC/FI. A fast ADC converter with high linear dynamic range makes it suited for analyzing complex mixtures of true unknowns —even at low concentrations. The spectrometer is designed for optimum throughput, operation and uptime. An optional combination EI/FI/FD ion source eliminates the need for source exchange, and provides library-searchable EI mass spectra and molecular weight information from the FI mass spectra. Although an optional CI source is available, FI does not require a reagent gas for molecular ion determination. GC/FI can also be used to characterize samples difficult to analyze by any other technique, such as unsubstituted alkanes. For the first time, GC/FI is available in a convenient and routine package. System applications include environmental, petroleum, polymers and materials, forensics, foods and flavors & fragrances.