Excite-coupled trapping ring electrode cell (eTREC): radial trapping field control, linearized excitation, and improved detection.

A novel excite-coupled Trapping Ring Electrode Cell (eTREC) was designed and developed. eTREC technology provides greater linearity in the excitation electric field along with minimized variation in radial trapping field during detection. The variation in the radial trapping electric field is reduced through postexcitation modulation of the trapping potentials applied to the Trapping Ring Electrode Cell (TREC). Linearization of the electric field generated during radio frequency (RF) excitation is accomplished by coupling the RF excitation to a novel electrode arrangement superimposed onto the trapping rings of a TREC. The coupling of RF excitation to the trap plates effectively reduces z-axis ejection and allows for a more uniform postexcitation radius for the entire ion population. Using this technology, sensitivity was increased by >50%, resolution of (13)C(2) and (34)S fine structure peaks was achieved with the peptide MMMMG (approximately 330,000 RP) on a 3 T system, and the limit of detection was significantly reduced.