Quantification of Sunscreen Benzophenone-4 in Hair Shampoos by Hydrophilic Interactions Thin-Layer Chromatography/Densitometry or Derivative UV Spectrophotometry.
Benzophenone-4 (BZ4) was separated from surfactants, dyes, preservatives, and other components of hair shampoos by thin-layer chromatography on silica gel 60 stationary phase, with ethyl acetate-ethanol-water-pH 6 phosphate buffer (15 : 7 : 5 : 1 v/v/v/v) as mobile phase. Densitometry scanning of chromatograms was performed at 285 nm. The densitometric calibration curve for BZ4 was nonlinear (second-degree polynomial), with R > 0.999. The limits of detection and quantification were ca. 0.03 and ca. 0.1 μg spot(-1), respectively. The results obtained by HPTLC-densitometry were compared to those obtained by zero and 2nd derivative UV spectrophotometry. In the case of spectrophotometric methods, calibration curves were linear with R > 0.9998. The chromatographic method was fully validated.
Department of Analytical Chemistry, Medical University of Lodz, Ulica Muszynskiego 1, 90-151 Lodz, Poland.
Anna W
AW
Sobańska
Department of Analytical Chemistry, Medical University of Lodz, Ulica Muszynskiego 1, 90-151 Lodz, Poland.
Katarzyna
K
Kałębasiak
Department of Analytical Chemistry, Medical University of Lodz, Ulica Muszynskiego 1, 90-151 Lodz, Poland.
Jarosław
J
Pyzowski
Department of Analytical Chemistry, Medical University of Lodz, Ulica Muszynskiego 1, 90-151 Lodz, Poland.
Elżbieta
E
Brzezińska