Nucleoside phosphoramidites bearing a adsorbent tert-butylphenyl-1H,1H,2H,2H-heptafluorodecyloxysilyl (BPFOS) group were used to synthesize fluorous-tagged oligonucleotides, viz. 5-mer, 10-mer, 13-mer, 17-mer, and 19-mer, which were subjected to liquid-phase extraction. The labeled oligomers were found to be highly hydrophobic in nature, become precipitated in water, therefore allowing easy purification from the failure sequences. The silyl fluorous group was deprotected by TBAF treatment and oligomers were easily purified by CH3CN/FC-72 liquid-liquid extraction. Fluorous-tagged oligonucleotides have high selectivity for the removal of failure sequences, high recoveries (typically 70-100%).