| Borate fusion is an extremely effective method of preparing cement, refractories, ceramics, rock, and similar materials for analysis by XRF, AA, and ICP. The samples are mixed in powdered form with a flux, usually lithium tetraborate or a mixture of lithium tetraborate and lithium metaborate; this mixture is heated until the flux melts, and the sample dissolves in it, yielding a clear, homogeneous melt. The melt can be cast as a fused disc for XRF, or dissolved in dilute nitric or hydrochloric acid for analysis in solution form. Recent advances in technique also allow borate fusion of troublesome samples containing sulfides, ferroalloys, etc.
Another advantage specific to XRF is that fused discs are homogeneous at the atomic level, eliminating partical size effects and mineralogical effects, as well as reducing matrix effects. For samples prepared as liquids, borate fusion is usually quicker than microwave dissolution in pressure vessels, and the use of hazardous acids such as HF is avoided.
SPEX SamplePrep offers Katanax automatic electric fluxers, which are fully programmable, and electrically powered for "Fusion Without Flames™." SPEX SamplePrep also offers graphite crucibles and handling tools for manual fusions with muffle furnaces, and the full line of high-quality SPEX SamplePrep fusion fluxes and additives. |
