Evaluation of binding selectivities of caged crown ligands toward heavy metals by electrospray ionization/quadrupole ion trap mass spectrometry

Citation
Sm. Blair et al., Evaluation of binding selectivities of caged crown ligands toward heavy metals by electrospray ionization/quadrupole ion trap mass spectrometry, ANALYT CHEM, 72(11), 2000, pp. 2433-2445
Citations number
46
Categorie Soggetti
Chemistry & Analysis","Spectroscopy /Instrumentation/Analytical Sciences
Journal title
ANALYTICAL CHEMISTRY
ISSN journal
00032700 → ACNP
Volume
72
Issue
11
Year of publication
2000
Pages
2433 - 2445
Database
ISI
SICI code
0003-2700(20000601)72:11<2433:EOBSOC>2.0.ZU;2-O
Abstract
Electrospray ionization (ESI)/quadrupole ion trap mass spectrometry is used to evaluate the heavy metal binding selectivities of five caged crown ethe rs and two polyether reference compounds in methanol solution. The binding preferences for Hg2+, Pb2+, Cd2+, and Cu2+ were analyzed by comparison of E SI mass spectral intensities with the aim of developing this method for the rapid screening of binding selectivities of new synthetic ligands, The cag e compounds preferentially bind Hg2+, except for the cage cryptand derivati ve, which favors Pb2+, The preference for Hg2+ stems from the favorable pos itioning of the nitrogen or sulfur atoms for linear coordination of Hg2+, w hereas the cryptand derivative favors Pb2+ because of its larger cavity siz e. The counterions of the metal salts influence the type of complexes obser ved in the ESI mass spectra because the strengths of the metal-anion bonds affect retention of the anion in the complexes.