pH-potentiometric study on rare earths and calcium binary and ternary complexes with DL-malic acid and L-hydroxyproline

Wang Ruiyao, Gao Feng, Niu Chunji*, Ni Jiazan, Jin Tianzhu, Wang Xiangyun

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The stability constants of M-L binary system and M-L-L′(M = La3+ ∼ Yb3+, Y3+ and Ca2+; L = DL-malic aicd, L′ = L-hydroxyproline) ternary system were determined by pH-potentiometric method under the simulating physiological condition(37 °C, I = 0.15 mol/L NaCl). The complex species MpLqL′rHs(abbr as pqrs) in the sytems were ascertained by program COMPLEX. The results show that there are three species(1101, 1100 and 1200) in M-L binary system and one species(1010) in M-L′ binary system. In addition to the above four species, a new species, 1112 was found in the M-L-L′ ternary system, which is the only species of mixed ligands. Rare earth ions form more stable complexes than calcium ion does and the stability differences between their complexes in the ternary system are less than that in the binary system. The distributions of all the species in La-L-L′ ternary system vs pH are discussed.

Original languageEnglish
Pages (from-to)3-4
Number of pages2
JournalJournal of Rare Earths
Volume16
Issue number1
Publication statusPublished - 1998
Externally publishedYes

Keywords

  • Calcium
  • DL-malic acid
  • L-hydroxyproline
  • Rare earths
  • Ternary complex

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