Y. Sakai et al., EFFECT OF THE POLY(OXYETHYLENE) CHAIN-LENGTH OF IONIC SURFACTANTS ON THE EXTRACTION OF ALKALI-METAL IONS, Bulletin of the Chemical Society of Japan, 66(10), 1993, pp. 3107-3109
The following three extractants were synthesized: C12H25-O(-CH2CH2O-)n
CH2-C6H3(OH)(NO2) (n = 3, 6, 9). The extraction constants for alkali m
etal ions were also determined. The extractability with an extractant
having three oxyethylene units decreases in the order Li+ > K+ > Na+ >
Cs+ greater than or similar to Rb+; for other extractants, K+ > Rb+ >
Cs+ > Na+ > Li+.