Table 7. Identified Metal Species for REEs (Nd, Eu, Dy, Er, and Yb) in Choline Chloride-Based DES with Ethylene Glycol, Urea, and Lactic Acid as HBDs.

	identified Ln3+ species
HBD	Nd	Eu	Dy	Er	Yb
ethylene glycol	[Nd(HBD)4.5–5]	[Eu(HBD)4–4.5]	[Dy(HBD)4–4.5]	[Er(HBD)4–4.5]	[Yb(HBD)4]
urea	[Nd(HBD)8–10]	[Eu(HBD)8–9]	[Dy(HBD)7–9]	[Er(HBD)7–8]	[Er(HBD)7–8]
lactic acid	[NdCl6]	[EuCl6–5]