We use several different standards and reference materials for the analysis of iron meteorites by LA-ICP-MS.  We have two steels from NIST, SRM1263a and SRM1158, which have both good and bad points (1158 has a lot of irrelevant elements for Fe meteorite analysis and 1263a has some heterogeneities in Nb, Ta and N [so not elements to worry about for Fe meteorites]).  John Wasson uses NBS809b as a standard, but this is now near impossible to find. 

We also use iron meteorites as reference materials (NB not really standards).  Ataxites are generally pretty uniform in their composition and Hoba is widely used as a reference.  However many irons are depleted in volatile elements and so it is not practical to use this for Au, Ge, Ga standardisation.  We also use the meteorite Filomena as a reference, though this has issues with Cr.  We also have a couple of other meteorite samples that work well for us and we are confident that we know the composition of the pieces that we have and that they are uniform.

I would echo Jerry's concern about the area which you are sampling - you need to ensure that you are getting something representative of the whole meteorite or you will get a misleading answer.

Richard Ash

Dear Florian,

pXRF is not an adaequate method for the analysis of iron meteorites. For classification (see papers by John Wasson and his group) you need precise and accurate data for Ni, Ge, and Ga. Depending on what you want to know you will also require an electron microprobe and LA-ICP-MS for the platinum group elements. 

Good luck, Ernst

Dear Dr. Florian Strobele, please have a good look at papers from Dr. Dong Hailiang at Miami University. His group pay more attention to clay stuff and standards for Fe-meteorite and publish lots of papers. Good luck.

Dear Florian, I have recently published a paper on Geostandards and Geoanalytical Research on the use of HHXRF or pXRF as you prefer, on the analysis and classification of iron meteorites. This method is very effective non destructive and very simple in the sample preparation. It is a complementary method of classification usually made by ICP-MS or INAA. Furthermore, it is a good method to obtain a bulk chemical composition of iron meteorites.

Article Chemical Analysis of Iron Meteorites Using a Hand-Held X-Ray...

Dear Florian et al.

I think the paper by Gemelli et al (GGR; 2014) provides a good evaluation (pros and cons) of HHXRF in the geochemical analyses of iron meteorites and their preliminary classification.

Luigi Folco

You will need to be sure that your analyzed area of the sample is truly representative of that sample.  The ubiquitous presence of intergrown kamacite and taenite in most Irons produces order-of-magnitude heterogeneity for several elements within a few millimeters on a polished surface. If you are not cognizant of this effect you will produce results that are misleading, at best, and more probably uninterpretable in detail.  A combination of spot analyses on compositionally distinct areas, with phase modal recombination of the area/volume data for the polished surface will be necessary if you are interested in 'bulk' chemical analyses.  On the other hand, if you interested in the mineral chemistry of the coexisting phases, this is a nice approach.

I agree with the posts above. Using the chondritic uniform reserviour would be smart.

Powder XRD is not a method for meteorite characterization. You need to do XRF for the Mg/Fe: Fe/Ni: determinations, and then ICPMS for the trace elements. EPMA for the minerals identification. Then you can classify the meteorite t ma proper class.  In any case you write to Professor Dr. Laurence A.J. Garvie, Research Professor and Collections Manager, Center for Meteorite Studies,Arizona State University,ISTB4, BLDG 75

781 East Terrace Rd

Tempe

AZ 85287-6004

USA

for help. He is very helpful. Best Regards, Partha

We use several different standards and reference materials for the analysis of iron meteorites by LA-ICP-MS.  We have two steels from NIST, SRM1263a and SRM1158, which have both good and bad points (1158 has a lot of irrelevant elements for Fe meteorite analysis and 1263a has some heterogeneities in Nb, Ta and N [so not elements to worry about for Fe meteorites]).  John Wasson uses NBS809b as a standard, but this is now near impossible to find. 

We also use iron meteorites as reference materials (NB not really standards).  Ataxites are generally pretty uniform in their composition and Hoba is widely used as a reference.  However many irons are depleted in volatile elements and so it is not practical to use this for Au, Ge, Ga standardisation.  We also use the meteorite Filomena as a reference, though this has issues with Cr.  We also have a couple of other meteorite samples that work well for us and we are confident that we know the composition of the pieces that we have and that they are uniform.

I would echo Jerry's concern about the area which you are sampling - you need to ensure that you are getting something representative of the whole meteorite or you will get a misleading answer.

Richard Ash