Work

When electrically charged molecules—ions—are accelerated by an electrical field, their speed depends on the ion’s charge and weight. By measuring the time it takes for the ions to pass a certain distance, the incidence of different molecules in a test can be determined. It was impossible, however, to use this technique on large molecules, such as proteins, before large ions could be produced in gaseous form. In 1987 Koichiro Tanaka showed that laser pulses could blast apart protein molecules so that ions in gaseous form are produced.