Customized Standard Reference Material Standard Reference Materials SRM of known elemental composition play an important role in the quality assurance QA of grass roots ex ploration programs and development projects SRMs are developed to meet measurement needs and as control samples They provide a known well characterized entity to compare and evaluate laboratory analysis results Unfortunately not all laboratory results are the same despite the fact they may be generated by the same analytical method such as fire assay with an atomic absorption finish There are variations to the technique that each lab uses as well as a variety of calibration p r o c e d u r e s w h i c h m a y l e a d t o v a s t l y d i f f e r e n t r e s u l t s o n y o u r s a m p l e s Some of these dif ferences include amount of litharge in the flux the flux to sample ratio reuse of the same crucibles age and state of repair of instrumentation diligence of analysts in calibration age of standards sample preparation etc Using hidden SRMs with values only known to you on your standards provides an excellent means to judge ac curacy and precision of the labs you are using This is critical for the QP to avoid future embarrassment and undermine confide nce in re sults in the investor s mind on the reliability of results Control Limits Confidence Intervals T olerance Interval Generally accepted results are those results lying within three stan dard deviations on either side of the certified values on the bottles rather than the 2 standard deviations listed on the bottle Actlabs has a presentation by L ynda Bloom Analytical Solutions and Maureen Leaver CANMET which can be provided to explain the rational for this This range of acceptability is called Control Limits The control lim its applications are set by the client Confidence Intervals are a range of values that estimate the reliability generally set a 95 probability of the certified value T olerance Interval is that range of values within which it has been cal culated that a specified percentage of individual values of measure ments will lie with a specified degree of confidence This parameter is used to measure the homogeneity of a reference material SRM Preparation In order to provide the exploration market with SRMs Actlabs has developed a set of rigorous sample preparation procedures W e can use natural soils rock ores or sediments collected by the client from their project area so their matrix is matched best cas e scenario on your samples Samples from 1 and up to 125 kg can be prepared as an SRM The whole sample is dried at 60 degrees then is crus hed pulverized and screened with 100 240 mesh 63 microns stainlesssteel sieve The resulting pulp goes through a blending s tep using a Stainless Steel industrial V blender The blend is achieved by the constant dividing and intermeshing particle movemen t by the two connected cylinders Inside the blender is a highspeed agitator bar to thoroughly mix the sample Each cylindrical leg has an access cover for easy material loading and cleaning A homogeneity test will show that all elements in the mixture were distributed evenly within the material After results of the homogeneity testing are determined the mixed material is packed in plastic bottles or in sealed foil pouches under nitrogen to prevent ox idation of sulphides Any suggested elements or group of elements can be certified this also applies to major minor and trace elements Actlabs ca n certify concentration of elements by using any digestion you will use for your projects or for total metals As we have perhaps the mos t diverse lab with virtually all instrumentation including fire assay nickel sulphide and lead atomic absorption gravimetric ICPOES ICPMS HRICPMS XRF INAA CNHS analyzers and many more we can develop values or can go round robin to other labs to certify values For more information please contact us at crmactlabscom P AGE 35