. . . . . . . . . . . . . . . . . . "SDN:L05::LAB48" . . . . . . "Instruments that measure isotopic ratios using an electron ionisation source. Atoms in purified samples are ionised using a beam of electrons under vacuum. Subsequently, ions are focused into a beam by an electromagnet and then separated into individual beams based on their mass/charge ratio."@en . . "isotope ratio mass spectrometers"@en . . . . "accepted"@en . . "IRMS" . "IRMS"@en . . . . . . . .