No abstract

An ultrasonic internecine grinding technique was investigated for the direct slurry nebulization of sintered fine ceramics in inductively coupled plasma atomic emission spectrometry. A sample block was ground with the same sample pestle fixed on an ultrasonic horn along with the same sample coarsely crushed in water for 10 min. The finely ground sample of 10-20 mg (0.5-0.7 mm in mean particle size) was obtained with ultrasonic vibration. The pH of the resultant slurry was adjusted to 12 with tetramethylammonium hydroxide. This slurry was stable and easily nebulized through an ordinary sample introduction system with the similar sensitivity to aqueous standard solutions. The present method was successfully applied to analyses of sintered ZrO 2 -Al 2 O 3 ceramic materials.

The degree of transportation of beryllium with H2O is measured under the upper mantle P/T conditions in order to examine the incorporation of 10Be in subduction zone magmas. 5.4±0.3% of original beryllium in the starting serpentinite is extracted with H2O from the system through the dehydration reaction of serpentine at 850°C and 1.5 GPa. It follows that the partial melting of oceanic lithosphere including 10Be‐rich sediment layer is not necessarily required for inclusion of the isotope in island‐arc lavas. We suggest that the dehydration processes in the subducted slab and mantle wedge materials dragged downward by the slab subduction govern the concentration of 10Be in arc lavas.

No abstract

No abstract