Editing Lawrencium (section)

==Preparation and purification==
Most isotopes of lawrencium can be produced by bombarding actinide ([[americium]] to [[einsteinium]]) targets with light ions (from [[boron]] to neon). The two most important isotopes, <sup>256</sup>Lr and <sup>260</sup>Lr, can be respectively produced by bombarding [[californium]]-249 with 70&nbsp;MeV [[boron]]-11 ions (producing lawrencium-256 and four [[neutron]]s) and by bombarding [[berkelium]]-249 with [[oxygen]]-18 (producing lawrencium-260, an alpha particle, and three neutrons).<ref name="Silva16423">{{harvnb|Silva|2011|pp=1642–3}}</ref> The two heaviest and longest-lived known isotopes, <sup>264</sup>Lr and <sup>266</sup>Lr, can only be produced at much lower yields as decay products of dubnium, whose progenitors are isotopes of moscovium and tennessine.

Both <sup>256</sup>Lr and <sup>260</sup>Lr have half-lives too short to allow a complete chemical purification process. Early experiments with <sup>256</sup>Lr therefore used rapid [[solvent extraction]], with the [[chelating agent]] [[thenoyltrifluoroacetone]] (TTA) dissolved in [[methyl isobutyl ketone]] (MIBK) as the [[organic phase]], and with the [[aqueous phase]] being buffered [[acetate]] solutions. Ions of different charge (+2, +3, or +4) will then extract into the organic phase under different [[pH]] ranges, but this method will not separate the trivalent actinides and thus <sup>256</sup>Lr must be identified by its emitted 8.24&nbsp;MeV alpha particles.<ref name="Silva16423" /> More recent methods have allowed rapid selective elution with α-HIB to take place in enough time to separate out the longer-lived isotope <sup>260</sup>Lr, which can be removed from the catcher foil with 0.05&nbsp;M&nbsp;[[hydrochloric acid]].<ref name="Silva16423" />