Principles of the Delayed Extraction Technique

Abstract

The delayed extraction (also known as pulsed extraction) technique involves the application of a time delay between the ionization pulse and an accelerating voltage pulse for desorption/ionization from a surface. This technique can achieve energy focusing in a matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometer and is used to improve mass resolving power. We explain the principles of delayed extraction (pulsed extraction) used in a MALDI TOF mass spectrometer. 1. QQ (delayed extraction, pulsed extraction) QQQQQQQ (matrix-assisted laser desorption/ionization: MALDI) Q QQQQQQQ QQ QQQQQQQQQ QQ Q ns QQQQQQQQQQQQQQ Q QQQ (time-of-flight: TOF) QQ QQQQ Q QQ QQQQ Q QQQQQQ (Fig. 1). QQQ QQQQQQ (time-of-flight mass spectrometry: TOFMS) Q QQ QQQQQQQQ 1) #. 2. 2), 3) MALDI TOFMS QQQ (Fig. 2). Q Q Q Q Q Q Q Q Q Q Q Q Q Q (Sample Plate) QQQQQQQQQ Q (Ground) QQQ V 0 QQQQQQQQ QQ Fig. 2 Q QQQQQ QQQQQQ v Q (1) QQQQQQ qV 0 1 2 Mv 2 (1) v 2V 0 q M 2V 0 2V 0 q M (2) q C Q M kg Q v m/s V 0 V Q