RESUMEN
Theoretical study and experimental test of a new ion trap mass analyzer-ladder electrode linear ion trap (LeLIT) were reported. The LeLIT was composed of two pairs of ladder electrodes and one pair of end-electrodes. By optimizing the geometric structure of ladder electrodes, we optimized the electric field distribution for optimum mass analysis. Since the distribution of electric field can be controlled by the adjustment of LeLIT structure, LeLIT have better performance than rectilinear ion trap theoretically. Due to its simpler structure than hyperbolic electrode LIT, LeLIT can be easily built. In this work, the height, width and field ratio were adjusted for optimizing the property of LeLIT, and a mass resolution of 10150 was obtained when the mass scan speed was 225 Da / s for a LeLIT with X0 ×Y0 = 9 mm×5 mm dimension. The preliminary experimental result showed that the LeLIT has proper tandem mass spectrometric performance as any conventional ion trap mass analyzer.
RESUMEN
The toroidal ion trap is an ideal candidate for miniaturized ion trap because it has much higher ion trapping capacity than a standard quadrupole ion trap of equal trapping dimensions. A novel toroidal ion trap mass analyzer with triangular electrode which contained a filament end cap, a detector endcap, an inner ring and an outer ring was reported. After designing and optimizing the electrodes by theoretical simulations, we found that the asymmetric triangle electrodes could reduce the affection from toroidal shape and improve the ion ejection rate and the mass resolution of the ion trap. The best design of the toroidal ion trap with a mass resolution of 1486 at m/z 609 was obtained.