@article{oai:kanazawa-u.repo.nii.ac.jp:00010347,
 author = {土田, 友一 and 本浄, 高治},
 issue = {11},
 journal = {分析化学 = Japan analyst},
 month = {Nov},
 note = {A new method for the separation of lanthanum(III) and barium(II) as their thenoyltrifluoroacetone (TTA) complexes with dibenzo-18-crown-6(DB18C6) in o-dichlorobenzene has been established by means of synergistic extraction and back-extraction combined with inductively coupled plasma atomic emisson spectrometry(ICP-AES). When the mixtures of La(III) and Ba(II) were extracted for 5 min at pH 4.5, only lanthanum(III) was extracted quantitatively, whereas barium(II) remained in the aqueous phase. After the phases were separated, barium(II) was extracted quantitatively for 5 min at pH 7.9 again. Then, the two phases were each shaken with 0.1 M HCl in order to back-extract lanthanum(III) and barium(II) from the organic phases; both metal ions were determined by ICP-AES. In the process, lanthanum(III) and barium(II) TTA chelates in o-dichlorobenzene formed stable adducts with DB18C6 (La(TTA)_3・nDB18C6 and Ba(TTA)_2・nDB18C6, n = 0 - 2). The stability constants(β_n) of the adducts determined by means of curve-fitting method were log β_1 = 3.7 and log β_2 = 5.9 for lanthanum(III), and log β_1 = 3.8 and log β_2 = 7.9 for barium(II). The extraction constant(log K) of lanthanum (III) adduct was - 3.7.},
 pages = {895--899},
 title = {テノイルトリフルオロアセトンとクラウンエーテルによるランタン(III)とバリウム(II)の協同抽出分離},
 volume = {49},
 year = {2000}
}