Lanthanum

Location:  Group 3, Period 6 (lanthanoid)
Atomic Weight:  138.9055
Coordination Number:  6 to 9, 10 for some compounds
Chemical Form in Solution:  La(OH)_y(H₂O)_x^+3-y

Storage & Handling:  Keep tightly sealed when not in use. Store and use at 20 ± 4°C. Do not pipet from container. Do not return portions removed for pipetting to container.

Chemical Compatibility:  Soluble in HCl and HNO₃. Avoid HF, H₃PO₄, H₂SO₄ and neutral to basic media. Stable with most metals and inorganic anions forming an insoluble carbonate, oxide, oxalate, and fluoride and sparingly soluble sulfates (La - Eu exhibit low sulfate solubility). Avoid mixing with elements / solutions containing moderate amounts of fluoride.

Stability:  2-100 ppb levels stable for months in 1% HNO₃ / LDPE container. 1-10,000 ppm solutions chemically stable for years in 2-5 % HNO₃ / LDPE container.

La Containing Samples (Preparation & Solution):  Metal (soluble in acids); Oxide (dissolved by heating in H₂O / HNO₃); Ores (carbonate fusion in Pt⁰ followed by HCl dissolution); Organic Matrices (dry ash and dissolve in 1:1 H₂O / HCl or HNO₃).