Intertek Genalysis Analytical Services
The intended end use of analytical data is the primary consideration when selecting the most appropriate analytical methods. Due to a wide range of applications, from greenfields exploration through to resource definition and production environments, key criteria to be considered include; accuracy and precision, detection limits, expected concentration of the target element/s, sample matrix and budget.
Sample preparation is a vital stage in the analytical process. Correct preparation procedures allow representative sub-sampling which is the foundation of quality analysis. For ease of selection packages have been created to cover the most commonly used procedures.
The choice of sample dissolution procedure, to get a sample into a form amenable to instrumental analysis, is important, and each has its own advantages and limitations. Consideration should be given to whether a partial or complete decomposition is required for each application when choosing between the various digestion techniques.
A selection of analytical packages are offered including a range of multi-element scans and commodity specific suites. The comprehensive multi-element packages incorporate the lowest detection limits that can be analysed and utilise both ICP-OES and ICP-MS instrumentation. Variations in element suites, instrumentation and detection limits offer more cost effective package options.
For greenfields exploration, various multi-element options are available. Where gold is a target element for reconnaissance soil and stream sediment surveys, an aqua regia digestion and a multi-element analysis by ICP-MS and ICP-OES is useful as both gold and a range of other elements can be determined cost effectively using the same digest. Aqua regia will digest gold and chalcophile elements in particular, however elements associated with silicates and more refractory minerals may only be partially digested. Four acid digestions will dissolve all but the most refractory minerals, with total analyses for most elements. If gold is not required, the four acid digestion and multi-element analysis is recommended for exploration work. Pressed powder XRF is a solid technique that is not subject to any digestion issues, however matrix and particle size effects can be limiting factors.
For detecting buried mineralisation, partial leaches on soils are an effective tool. Similarly, plant tissue or groundwater, which can be sampled easily and cheaply, can be analysed in conjunction with, or as an alternative to, conventional media. Analyses available using these methods are listed in the Partial Digests, Biogeochemistry and Hydrogeochemistry sections. Orientation surveys are particularly important when using these techniques and it is advisable to discuss your needs with us in advance.
Fused bead XRF is particularly useful for the analysis of bulk commodities such as iron ore and bauxite, and is listed in the Commodities section. Moisture correction is routinely carried out and samples are reported on a dry basis. This technique is not suitable for samples containing high sulphides.
Precious metals are best analysed by fire assay, with lead collection used to analyse Au, Pt and Pd, while nickel sulphide collection is the required method for the full suite of platinum group elements (PGE).
Complete lithogeochemistry packages are available using a combination of methods to analyse the widest range of elements. Fusion ICP-MS is best for the analysis of REE and HFSE as the host minerals are in most cases refractory. Lithium borate fusion and either XRF or ICP-OES remain the best methods for whole rock analyses.
The most common methods offered are listed in the Schedule, however it is not an exhaustive list of services. We encourage our clients to discuss their projects with us and where possible visit the laboratories to assist with selection of the most appropriate analytical solutions for the particular applications.