Liquid-liquid extraction separation of thallium(I) with cryptand 222 and erythrosin

Understanding the Stabilization and Tunability of Divalent Europium 2.2.2B Cryptates

“…Organic macrocycles are excellent metal ion chelators and have been extensively studied for their efficacy in solution-phase separations. − Cryptands such as 2.2.2 and 2.2.2B (5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]­hexacos-5-ene) depicted in Figure are well-known for their high affinity for low valent metals due to the high number of coordination sites for metal ions and large cavity size. ,− Additionally, the steric encumbrance of the cryptand prevents interaction between redox active species from the environment surrounding the cryptand with the metal ion the cryptand encapsulates . This property is especially advantageous for stabilizing low valent metal ions that are susceptible to oxidation such as divalent lanthanides.…”

Preconcentration of thallium (I) by single drop microextraction with electrothermal atomic absorption spectroscopy detection using dicyclohexano-18-crown-6 as extractant system

“…The separation of thallium (I) has been intensively studied through the formation of ion-pair complex with basic triphenymethane dye [11], with cryptand 2,2,2, erythrosine [12] and benzo-15-crown-5 [13], 18-crown-6 [14] and dibenzo-24-crown-8 [15] or 12-crown-4 [16] with picrate. The complexation reaction between Tl (I) and crown ethers in organic solvents at 25 • C with stoichiometry of 1:1 has been studied and the best crown ether was found to be DCH-18-crown-6 [17].…”

Taking a deeper look into the roles of amines in atomic absorption spectrometry

“…129 On the other hand, various typical cryptands (221, 222 and 222B) have allowed the extraction of various metals such as Cu (II) , Tl (I) , Mn (II) and Pb (II) at neutral pHs in solvents like chloroform, dichloromethane and toluene, using eosin or erythrosin as the counterion, and detection by FAAS. [130][131][132][133] Many sorbents can better preconcentrate alkaline earth and transition elements (Ni, Pb, Cu, Co, Mn, Cd and Zn) simultaneously in neutral solutions because the metal cation is less affected by the hydroxyl groups and the ligands by protons. However, identical sorbents can better selectively separate precious metals (Pt, Pd, Ag and Au) under acidic conditions because metal cations solubilise better.…”