Greener liquid chromatography using a guard column with micellar mobile phase for separation of some pharmaceuticals and determination ofparabens

In this research, a greener chromatography employing a short column, Zorbax SB C18 cartridge (12.5×4.6 mm, 5 μm) commonly used as a guard column in a reverse phase high performance liquid chromatography (RP-HPLC), was utilized as the analytical column in conjunction with a more eco-friendly micellar mobile phase of sodium dodecyl sulfate (SDS) for separation tertiary mixtures of local anesthetics and antihistamines; and binary mixture of colds drugs; and quaternary mixture of some parabens with different separation conditions. The chromatographic behavior of these analytes was studied to demonstrate separation efficiency of this guard column in a micellar mobile phase. Moreover, this column and SDS mobile phase was exploited for determination of parabens in 64 samples of cosmetic product, both those that were produced locally in the community and those that were commercially manufactured. Linear calibration graphs of the parabens as detected at 254 nm were obtained in the range of 1–100 μmol L−1 with R2>0.9990. Percentage recoveries were 92.4–109.2 with %RSD<3, and the limit of detection and quantitation were 0.04–0.10 and 0.20–0.80 μmol L−1, respectively. This analytical system is not only greener but also faster and employing simpler sample preparation than a conventional liquid chromatographic system.