Electrophoretic separation of pressurized hot water extracts of Hibiscus sabdariffa L. using vitamin C as background electrolyte and contactless conductivity detection

Abstract

Construction of a contactless conductivity detector with a separate small dimension detection cell and integration into an automated capillary electrophoresis device is described. An optimized separation procedure of the pressurized hot water extract of Hibiscus sabdariffa L. and implementation of L-ascorbic acid as a novel background electrolyte in capillary zone electrophoresis with contactless conductivity detection are described. Optimized conditions allowed a rapid separation in less than 7 minutes with complementary data of UV-VIS absorbance and contactless conductivity detectors recorded simultaneously. The pressurized hot water extraction showed superior recovery to classical cold water extraction with increased peak areas by 9.4 times ± 9.7%, 2.8 times ± 9.7% and 4.1 times ± 7.2% for pigments, inorganic cations and total peak area, respectively.