Overview

The thermal ionization mass spectrometer facility at Duke University, analyzes the isotopic composition of trace elements in rocks, sediments, water, and environmental samples. We are engaged in research in geochemistry, marine chemistry, paleoclimate, geochronology, radiogenic isotope studies, and stable isotope geochemistry. Our collective facilities include a fully automated Thermo Scientific TRITON thermal ionization mass spectrometer, VG PlasmaQuad-3 inductively-coupled plasma mass spectrometry ICP-MS, gamma spectrometer, and delay coincidence alpha counters.

The centerpiece of the facility is a fully automated Thermo Scientific TRITON thermal ionization mass spectrometer with Virtual Amplifiers, Dynamic Zoom and all-carbon plug-in Faraday cups. The instrument is operated with an abundance sensitivity of around 1 ppm, allowing precise measurement of a large spectrum of isotopes in natural samples. Currently isotopes of rubidium, strontium, and boron are routinely measured in fully automated mode. For boron isotopes we have developed a new low-blank matrix solution that enhances BO₂- ionization and provide a stable ion beam with minimum isotopic fractionation. Boron blank levels were tested by isotope dilution methodology (SRM-952) and is less than 15 pg.