Graphite is a tough one to dissolve. It can be dissolved/digested using perchloric acid with vanadium added as a catalyst (addition of vanadium is very important).
The method I am most familiar with uses 1 gram of sample + 18 mL sulfuric + 15 mL conc. perchloric acid in a glass digestion flask with condenser (do not use perchloric acid in a microwave furnace under any circumstances). The condenser is needed to contain any volatiles. In addition, 10 mg of V is added as either the pentoxide or in solution form as V+5 to act as a catalyst (I use 1 mL of the Inorganic Ventures' 10,000 ug/mL Vanadium standard, which is very pure and the V is in the +5 oxidation state). I have been able to decompose even charcoal and coke using the V+5 catalyst and I suspect this method would work for graphite carbon. Finally, graphite carbon would present no spectral interferences to an ICP-OES measurement.
Вторая возможность - идти через "пиранью", http://en.wikipedia.org/wiki/Piranha_solution
Что вы об этом думаете? Какая возможность предпочтительнее? Действительно ли углерод перейдет в раствор? Весь или часть улетит в виде CO2?