Cationic gemini pyrrolidinium surfactants based sweeping-micellar electrokinetic chromatography for simultaneous detection of nine organic pollutants in environmental water

- Gemini pyrrolidinium surfactants were used as carriers in sweeping-MEKC.
- C16-4-C16PB is the most suitable sweeping carrier.
- Nine organic water pollutants were simultaneously concentrated and separated.
- Sensitivity enhancement factors for nine analytes are in range of 310-580.
- C16-4-C16PB-based sweeping-MEKC is suited for the analysis of real water samples.

A series of novel cationic gemini surfactants with pyrrolidinium head groups, 1,1′-(butane-1,s-alkyl) bis (1-alkylpyrrolidinium) (Cn-4-CnPB, n = 12, 14, 16), were employed as carriers in sweeping-micellar electrokinetic chromatography (sweeping-MEKC) for simultaneous detection of nine organic water pollutants, including polycyclic aromatic hydrocarbons, sulfonamides and steroids. The sweeping and separation conditions were optimized. Cn-4-CnPB (n = 12, 14, 16) were compared with cetyltrimethylammonium bromide (CTAB) in terms of their abilities to preconcentrate and separate the nine analytes. Under the optimized conditions, the sensitivity enhancement factors based on the peak height (SEFsHeight) were ca. 310-580 of C16-4-C16PB, which were higher than those of C14-4-C14PB (120-290) and C12-4-C12PB (110-160). Meanwhile, the SEFsHeight of C16-4-C16PB were higher than those of 30% (v/v) methanol-modified CTAB (140-320). The C16-4-C16PB based sweeping-MEKC, coupled with offline solid phase extraction and UV detection (228 nm), was used to analyze spiked environmental water samples. The nine analytes were successfully separated and detected. The limit of detection (S/N = 3) was in range of 2.79-3.76 ng/mL, and the recovery ranged from 70.8% to 95.5% with the RSDs less than 9.89%. This study confirms that the C16-4-C16PB based sweeping-MEKC has significant advantages over the CTAB based sweeping-MEKC and it is a promising method for sensitive and simultaneous detection of polycyclic aromatic hydrocarbons, sulfonamides and steroids in environmental water samples.