ABSTRACT
The time-of-flight (TOF) inductively coupled plasma mass spectrometer (ICP-MS) instrumentation has come about because of its ability to sample all ions generated in the plasma at exactly the same time, which is ideally suited for multielement determinations of rapid transient signals, high-precision isotope ratio analysis, fast data acquisition for high-throughput workloads, and the rapid semiquantitative fingerprinting of unknown samples. To understand the benefits of this mass separation device, this chapter looks at its fundamental principles. The ion beam is then chopped by using a pulsed voltage supply coupled to the orthogonal accelerator to provide repetitive voltage slices at a frequency of a few kilohertz. The ability of a TOF system to capture a full mass spectrum, approximately three orders of magnitude faster than a quadrupole, translates into three major benefits-multielement determinations in a fast transient peak, improved precision, especially for isotope ratioing techniques, and rapid data acquisition for carrying out qualitative or semiquantitative scans.
