Stable Isotope Ratio Testing
Brooks Applied Labs currently offers stable isotope ratio testing of various elements for application to environmental forensic studies. Each element has a unique isotopic pattern and small differences in the ratios of these isotopes can help in identification of the source, transport and biogeochemical fate of elements in atmospheric bulk deposition, soils, freshwater, and seawater matrices.
Typically, accurate stable metal isotope measurement is achieved by thermal ionization mass spectrometry which can only be found in academic research environments. Brooks Applied Labs utilizes an Inductively Coupled Plasma Mass Spectrometer equipped with a Dynamic Reaction Cell (DRC) to achieve similar results with appropriate QA/QC. This specific instrument not only removes interferences for low level analysis of various matrices, but also allows extremely accurate and precise determination of isotopic ratios limited with counting statistics (<0.1% most ratios). Standard ICP-MS platforms cannot overcome the sinusoidal signal generated from the peristaltic pump associated with the sample introduction system. The DRC technology facilitates “dynamic bandpass smoothing” which normalizes the ion beam after ionization and greatly reduces the internal variability and increases precision. The confidence in isotopic ratio testing is also typically limited to sample concentration and matrix interferences. By identifying these interferences and implementation of pre-concentration techniques and appropriate sample preparation methods the applicability of lead isotopic ratio testing for most matrices is now a reality. In addition, institution of proper sampling plans is a necessity to ensure all localized variables are identified to account for as many variables as possible.
Use of stable isotope ratio testing can often decrease the scope of work for investigative projects ultimately reducing the cost of the investigation and increasing the confidence in results due to the absolute nature of the testing procedure. This is especially important when dealing with tort and environmental forensic litigation cases.
For project inquiries, applicability of methodologies, and pricing information feel free to contact us.