 An application that has almost fallen out of use with the introduction of affordable superconducting magnets is the use of europium complexes , such as Eu ( fod ) 3 , as shift reagents in NMR spectroscopy . Chiral shift reagents , such as Eu ( hfc ) 3 , are still used to determine enantiomeric purity . 
 An application <a href='null_relcl' title='1'><mark>that</mark></a><a href='been_done' title='2'><mark>has</mark></a> almost fallen out of use with the introduction of affordable superconducting magnets <a href='drop_aux' title='3'><mark>is</mark></a>the use of europium complexes , such as Eu ( fod ) 3 , as shift reagents in NMR spectroscopy . Chiral shift reagents , such as Eu ( hfc ) 3 , are still used to determine enantiomeric purity . 
An application done almost fallen outt of use with da introduction of affordable superconducting magnets tdause of europium complexes , such as Eu ( fod ) 3 , as shift reagents in NMR spectroscopy . Chiral shift reagents , such as Eu ( hfc ) 3 , r still used to determine enantiomeric purity .