Thin layer chromatographic separation of pesticides, decachlorobiphenyl, and nucleosides with micellar solutions

Abstract

The use of micellar solutions as mobile phases in thin layer chromatography (TLC) Is described for the first time. The possible advantages of micellar solutions over traditional pure and mixed solvent systems are described. , '-DDT; ,-'-DDD; p.p'DDE and decachlorobiphenyl were chromatographed using aqueous solutions of sodium dodecyl sulfate (SDS) with polyamide and alumina thin layer sheets. A reversed micellar solution was shown to separate the nucleosides adenosine, cytidine, guanosine, and uridine using a reversed phase TLC sheet. Possible mechanisms to account for the observed chromatographic behavior are discussed.

Utilization of Micelle-Mimetic Intramolecular Ionene Aggregates as the Mobile Phase in Pseudophase Thin-Layer Liquid Chromatography.

“…Relevant properties of ionene solutions The conformation of ionenes in aqueous solutions is thought to vary from that of rodlike or extended species for the relatively hydrophilic ionenes, such as the [3,6]-ionene to globular or micelle-like for amphiphilic ionenes as the [3,16]-ionene.1'2 Such latter amphiphilic ionenes, in contrast to micelle systems, are macromolecular entities and possess no critical aggregation concentration since their micelle-like domains are formed intrapolymerically as they fold-up in an accordion-like manner (Fig. 1).5 Like aqueous micelles, such aggregated ionene has a hydrophobic inner region and an outer hydrocarbon-water interface of high charge density.…”

“…For example, several ortho-, meta-, and para-disubstituted benzenes, other representative positional isomers, and some quinones and steroids could be separated if aqueous solutions of the [3,16]-ionene at concentrations ranging from 5.0 to 22.0 mg/ml (Table 2). Both the [3,6]-and [3,16]-ionenes appeared to bind somewhat to the polyamide and cellulose. Previously, the cationic micelle-forming surfactant, hexadecyltrimethylammonium bromide (CTAB), had also been reported to bind to such stationary phases.6 Although only briefly investigated, it appears that silica gel stationary phases are of limited use when using ionene-containing mobile phases.…”

“…8 It is interesting to note that the effect of increasing ionene concentration upon a solute's R f value depends upon both the type of ionene employed and the charge state of the solute. Figures 2 and 3 illustrate how a change in the ionene concentration affects the Rf values of ortho-, mew-, and para-substituted isomeric phenylphenols, aminobenzoic acids and nitrobenzonitriles on polyamide with [3,16]-and [3,6]-ionene in the mobile phase, respectively. Such plots can be utilized to determine the optimum ionene concentration required to achieve a desired separation.…”

“…S Previously, aqueous solutions of surfactant micelles have been found to be effective as the mobile phase (pseudophase) for thin-layer liquid chromatographic separations. [6][7][8][9][10][11] In comparison to conventional TLC mobile phases, advantages are accrued by the use of aqueous micellar mobile phases due to their low toxicity, nonflammability, biodegradability, and ability to separate simultaneously both hydrophilic and hydrophobic analytes. [6][7][8][9][10][11] In addition, their use can some- times enhance the TLC detection of fluorescent species.12"3 The two primary limitations with micellar mobile phases in TLC stem from the fact that their aqueous solutions exhibit significant frothing (foaming) and that it is difficult to recover the separated analyte(s) from such micelle solutions due to formation of emulsions when extraction with organic solvents is attempted.…”

“…[6][7][8][9][10][11] In comparison to conventional TLC mobile phases, advantages are accrued by the use of aqueous micellar mobile phases due to their low toxicity, nonflammability, biodegradability, and ability to separate simultaneously both hydrophilic and hydrophobic analytes. [6][7][8][9][10][11] In addition, their use can some- times enhance the TLC detection of fluorescent species.12"3 The two primary limitations with micellar mobile phases in TLC stem from the fact that their aqueous solutions exhibit significant frothing (foaming) and that it is difficult to recover the separated analyte(s) from such micelle solutions due to formation of emulsions when extraction with organic solvents is attempted. Recently, it has been observed that amphiphilic ionenes can act as micelle-mimetic agents because they exhibit many of the properties exhibited by traditional surfactant micelles, such as significant counterion binding, substrate solubilization, and catalytic rate enhancement effects.1 4 As in the case of surfactant micelles, an analyte molecule can partition and bind to an aqueous ionene via electrostatic and/or hydrophobic interactions since the hydrophobic ionenes possess a high positive surface charge density and hydrophobic region (Fig.…”