Lithium metaborate is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...

, boron, and

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

with elemental formula . It is often encountered as a hydrate, , where ''n'' is usually 2 or 4. However, these formulas do not describe the actual structure of the solids. Lithium metaborate is one of the

borate A borate is any of several boron oxyanions, negative ions consisting of boron and oxygen, such as orthoborate , metaborate , or tetraborate ; or any salt with such anions, such as sodium metaborate, and disodium tetraborate . The name also re ...

s, a large family of

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

s (ionic compounds) with anions consisting of boron, oxygen, and

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

Structure

Lithium metaborate has several crystal forms. The γ form is stable at 15 kbar and 950 °C. It has a polymeric cation consisting of a tridimensional regular array of tetrahedra sharing

vertices, alernating with lithium cations, each also surrounded by four oxygen atoms. The B-O distances are 148.3 pm, the Li-O distances are 196 pm.

Applications

Laboratory

Molten lithium metaborate, often mixed with

lithium tetraborate Lithium borate, also known as lithium tetraborate is an inorganic compound with the formula Li2B4O7. A colorless solid, lithium borate is used in making glasses and ceramics. Structure Its structure consists of a polymeric borate backbone. The Li ...

, is used to dissolve oxide samples for analysis by XRF, AAS,

ICP-OES Inductively coupled plasma atomic emission spectroscopy (ICP-AES), also referred to as inductively coupled plasma optical emission spectroscopy (ICP-OES), is an analytical technique used for the detection of chemical elements. It is a type of emiss ...

, ICP-AES, and

ICP-MS Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry that uses an inductively coupled plasma to ionize the sample. It atomizes the sample and creates atomic and small polyatomic ions, which are then detected. It is ...

, modern versions of classical bead test. The process may be used also to facilitate the dissolution of oxides in acids for wet analysis. Small amounts of

lithium bromide Lithium bromide (LiBr) is a chemical compound of lithium and bromine. Its extreme hygroscopic character makes LiBr useful as a desiccant in certain air conditioning systems.Wietelmann, Ulrich and Bauer, Richard J. (2005) "Lithium and Lithium Compo ...

] or

lithium iodide Lithium iodide, or LiI, is a compound of lithium and iodine. When exposed to air, it becomes yellow in color, due to the oxidation of iodide to iodine. It crystallizes in the NaCl motif. It can participate in various hydrates.Wietelmann, Ulrich ...

may be added as

mold A mold () or mould () is one of the structures certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not ...

and

crucible A crucible is a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures. While crucibles were historically usually made from clay, they can be made from any material that withstands te ...

release agent A release agent (also mold release agent, release coating, or mold release coating) is a chemical used to prevent other materials from bonding to surfaces. It can provide a solution in processes involving mold release, die-cast release, plastic r ...

s. Lithium metaborate dissolves acidic oxides with ''x'' < ''y'', such as SiO₂ , , , , , , , and Fe₂O₃. Lithium tetraborate, on the other hand, dissolves basic oxides with ''x'' > ''y'', such as

CaO Cao or CAO may refer to: Mythology *Cao (bull), a legendary bull in Meitei mythology Companies or organizations * Air China Cargo, ICAO airline designator CAO *CA Oradea, Romanian football club *CA Osasuna, Spanish football club *Canadian Assoc ...

MgO Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...

and other oxides of the

alkali metals The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...

and

alkaline earth metals The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).. The elements have very similar properties: they are all ...

. Most oxides are best dissolved in a mixture of the two lithium borate salts, for spectrochemical analysis.

References

David R. Lide (1998): ''Handbook of Chemistry and Physics'', edition 87, pages 4–66. CRC Press. M. Marezio and J. P. Remeika (1966): "Polymorphism of LiMO2 Compounds and High‐Pressure Single‐Crystal Synthesis of LiBO2". ''Journal of Chemical Physics'', volume 44, issue 9, pages 3348-. Terrance D. Hettipathirana (2004): "Simultaneous determination of parts-per-million level Cr, As, Cd and Pb, and major elements in low level contaminated soils using borate fusion and energy dispersive X-ray fluorescence spectrometry with polarized excitation". ''Spectrochimica Acta Part B: Atomic Spectroscopy'', volume 59, issue 2, pages 223-229. Fernand Claisse (2003):
Fusion and fluxes
. ''Comprehensive Analytical Chemistry: Sample Preparation for Trace Element Analysis'', volume 41, pages 301-311. Borates Lithium salts {{inorganic-compound-stub