Ethylene Glycol as New Mobile Phase for Resolution of Two-Component Mixture of Cationic Surfactants on Alumina Surface

Abstract

Aqueous ethylene glycol (ethane 1,2 diol) as a green mobile phase has been used for thin layer chromatographic (TLC) studies of cationic surfactants on alumina layers. Nineteen solvent systems were used to examine the mobility of the surfactants and to discover the best TLC system for the selective separation of dodecyl trimethylammonium bromide (DTAB) from multi-component mixture of other surfactants. Among the TLC systems studied, M₃ (ethylene glycol: water, 8:2) was best for achieving the selective separation of DTAB from multi-component mixture of other surfactants because in this mobile phase mobility of all surfactants except DTAB were insignificant. Effect of organic additives in aqueous ethylene glycol mobile phase on the mobility of surfactants was examined. The results obtained on laboratory made alumina TLC plates and commercially available precoated alumina HPTLC plates were compared. The lower limits of detection of DTAB, CPC, CTAB, HDTAC, and TTAB were 0.02, 0.05, 0.04, 0.06, or 0.08 µg per zone respectively. The resolution of mixture of cationic surfactants was also examined in the presence metal cations as an impurity in the analyzed sample.

Keywords:

• Alumina
• ethylene glycol
• identification
• resolution
• surfactants
• thin layer chromatography (TLC)

Acknowledgments

The authors are thankful to the chairman of the Department of Applied Chemistry, Aligarh Muslim University, Aligarh for providing research facilities and the Deanship of Scientific Research at King Saud University for financial support. N. H. is thankful to the University Grants Commission (UGC), India for providing financial assistance for research work.

Notes

T = tailed spot (R_L-R_T ≥ 0.3).

T = tailed spot.