Use of Nonionic Poly(Ethylene glycol) p-Isooctyl-Phenyl Ether (Triton X-100) Surfactant Mobile Phases in the Thin-Layer Chromatography of Heavy-Metal Cations

Abstract

The analytical potential of poly(ethylene glycol) p-isooctyl-phenyl ether (Triton X-100), a nonionic surfactant, is used as a mobile phase in the thin-layer chromatographic separation of heavy-metal cations. The surfactant concentration below its critical micellar concentration (CMC) as well as above the CMC value is used to investigate the migrational behavior of some heavy-metal ions on silica gel layers. The mobility of the metal ions is found to change marginally with the increase of surfactant concentration from 0.001M (below CMC) to 0.1M (above CMC). The influence of the pH of the medium, nonelectrolyte organic (urea and alkanols), and inorganic electrolyte (NaCI) additives in the surfactant containing mobile phase on the mobility of heavy metals on the silica gel layer is examined. For separating metal ions, surfactant must be used in the presence of buffers. Triton X-100 (0.02M) at pH 2.3 is found to be the best mobile phase for the separation of heavy-metal cations. In general, the presence of alcohol in aqueous surfactant solutions results in a decrease in the mobility of metal ions. Besides Cu2+ and Fe3+, all of the metal ions show a trend of increasing the retardation factor beyond a minima at 0.1 or 0.3M of added urea or NaCl. The proposed method is successfully applied for the simultaneous detection of Zn2+ and Cd2+ from a spiked human blood sample.

Speciation of Chromium by High-Performance Thin-Layer Chromatography with Direct Determination by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

“…Separation of the chromium species can therefore be achieved with just water as a mobile phase. However, since the presence of Tx-100 did not affect their sharp separation, it could be added to the sample to separate additional cations 4 without risk of interfering with the speciation of the chromium species. A typical spectrum is shown in Figure 1, where the Cr 3+ peak is located at the point of application on the plate and the Cr 6+ peak is located at the solvent front, roughly 12 mm above the point of application.…”

“…Although more commonly used for the separation of organic compounds, procedures for the separation of Cr 6+ and Cr 3+ on silica gel plates have been developed using a mixture of methanol, dimethylamine, and formic acid, but only semiquantitative determination was achieved through spot area measurements . Other heavy metal cations (Ni 2+ −Pb 2+ , Cd 2+ −Cu 2+ , Ni 2+ −Zn 2+ , Co 2+ −Fe 3+ , Ni 2+ −Bi 3+ , and more) have also been separated on TLC plates with aqueous mobile phases containing the nonionic surfactant Triton X-100 (Tx-100) …”

“…3 Other heavy metal cations (Ni 2+ -Pb 2+ , Cd 2+ -Cu 2+ , Ni 2+ -Zn 2+ , Co 2+ -Fe 3+ , Ni 2+ -Bi 3+ , and more) have also been separated on TLC plates with aqueous mobile phases containing the nonionic surfactant Triton X-100 (Tx-100). 4 Several groups have explored the direct coupling of TLC with MS, mainly for the analysis of organic compounds by matrixassisted laser desorption/ionization-mass spectrometry, but the process is complicated by the necessity of adding a matrix layer to the TLC plate. [5][6][7] The use of a Nd:YAG laser was also investigated for the qualitative analysis of lubricating oil additives by laser microprobe mass spectrometry.…”

Ionic liquid as separation enhancer in thin-layer chromatography of biosurfactants: mutual separation of sodium cholate, sodium deoxycholate and sodium taurocholate

“…Various analytical methods have been used in separation science, but thin-layer chromatography (TLC) is the most popular analytical tool used for separation because it is simple, rapid, versatile and cost-effective (Mohammad and Hina 2005;Mohammad and Bhawani 2008;Mohammad et al 2010;Mohammad et al 2013). Several inorganic, organic and aqueous-organic mobile phases and different stationary phases have been used in TLC analysis of surfactants (Mohammad and Agrawal 2001;Mohammad et al 2002;Touchstone 1992;Gocan 2002). Most of mixed aqueous-organic and organic solvents previously used in chromatographic analysis need to be replaced by environmentally benign solvent systems in order to reduce their adverse impact on the environment.…”