Аннотация:Thirty‐seven trace elements, including rare‐earth elements, have been determined by ICP‐MS in twenty‐eight international rock standards using routine sample preparation techniques. Samples were decomposed by either pressurized HF‐HCIO 4 ‐aqua regia attack, or by lithium borate fusion. Generally, the ICP‐MS data for geological rock standards presented here agree well with certified values. However, the results for light rare earth elements appear to be systematically low in comparison with the published working values.