Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Facility
The TERRA inductively coupled plasma mass spectrometry (ICP-MS) facility has two mass spectrometers, a single quadrupole PerkinElmer ELAN DRC II ICP-MS and a tandem Agilent 8900 ICP-MS/MS (often called a “triple” quadrupole ICP-MS). In general, ICP-MS is the preferred method for multiple trace element analysis down to ultra-low levels (where the technique is geared) in complex natural samples. The TERRA ICP-MS facility currently only undertakes trace element analyses on solutions (natural waters, experimental leaches, or dissolved solid materials).
The Agilent 8900 is the facility’s flagship instrument and is equipped with He gas for kinetic energy discrimination (KED) based interference reduction as well as multiple reaction gases (H2, O2, N2O) for highly controlled interference-free analyte measurement using “on-mass” or “mass-shift” strategies. The 8900 is coupled with an Elemental Scientific (ESI) SC-4DX autosampler equipped with an ultra-low particulate arrester (ULPA) air filter and FAST system for vacuum pump/injection valve driven solution sample introduction with high throughput, enhanced washout, and under ultra-clean conditions. This instrument is the primary connection to the facility’s new low-metal clean laboratory.
The ELAN DRC II ICP-MS is run only in the absence of gases in the Dynamic Reaction Cell and is the facility’s instrument dedicated to higher-matrix and higher-abundance samples. The ELAN DRC II is coupled with a CETAC ASX-520 autosampler.
The low-metal clean laboratory is supplied with positively pressured, high-efficiency particulate air (HEPA) filtered air. All work surfaces are polypropylene or epoxy resin and the laboratory workflow is aided by three polypropylene vertical laminar flow exhausted work stations with ULPA filtered air supplies. These work stations allow for sample preparation and acid distillation under better than ISO Class 4 (Class 10) conditions. Ultra-pure Type 1 water is produced within the laboratory from a Type 2 water supply using a Millipore Sigma Milli-Q IQ 7003 system with a final foot-pedal driven Milli-Q IQ Element dispenser for our most demanding, low-blank applications. Reagent acids (HF, HNO3, HCl) are distilled in-house (up to 3 times) with 3 Savillex DST-1000 acid purification systems. Ultra-pure acids (on par or cleaner than expensive high-purity acids) can be purchased directly from the facility for specialized purposes on campus. Acid digestions and sample evaporation are performed on our acid-inert Savillex HPX-200 hotplates with TeflonTM coated graphite inserts for tightly controlled temperature (±2 °C) handling.
At present, the application/method focus of the facility is on the low-blank and high-precision ultra-trace measurement of geological and environmental samples using a specialized external calibration method capable of producing high-quality data for ≥45 trace elements in parallel. For geological samples, the facility is currently equipped to digest non-refractory mineral bearing samples (i.e., those free of minerals like zircon), which includes mafic to intermediate igneous rocks, fine-grained sediment or mudrocks, carbonates, and detritus-poor iron formation. The facility also has experience with niche applications such as single mineral grain (e.g., quartz, olivine, apatite) solution chemical analysis. For natural water samples, the facility is equipped to measure low-salinity samples such as river and ground waters for major ions and ultra-low abundance trace elements such as the rare earth elements; however, users are asked to reach out to the facility to discuss field sampling and preservation strategies in advance of field work. The ultra-low abundance of these elements makes them highly amenable to contamination during handling and the facility can provide materials, acids, and guidance in best practices for the highest chances of successful low-blank water sampling. Other applications may be possible if they do not compromise the primary workflows of the facility but need to be discussed with both facility leaders, Drs. Inês Nobre Silva and Michael Babechuk, prior to sample submission. Please note that tungsten carbide-milled samples must be declared and may not be processed due to our routine low-level W measurement applications.
The low-metal clean laboratory and Agilent 8900 ICP-MS system were developed with funding from the Canada Foundation for Innovation (CFI) via the John R. Evans Leaders Fund (JELF) program and the Leverage Research & Development program of the Government of Newfoundland & Labrador Department of Tourism, Culture, Industry & Innovation (now Department of Industry, Energy & Technology).
Funding was secured by Dr. Michael Babechuk (Project Leader) and co-investigators Drs. John Hanchar and Stephen Piercey.