The typical electropherograms of standard mixture of pyrethroids and real samples. 1, Cyfluthrin; 2, fenpropathrin; 3, tetramethrin. a, Blank peach sample; b, peach sample; c, crab apple sample; d, standard mixture of pyrethroids under normal condition; e, standard mixture of pyrethroids under HS-ITME–CE. Analytical conditions: 120 mM SDS, 50 mM H3PO4, 15% acetonitrile, and 15% 2-propanol, at pH of 2.00, applied voltage of 30 kV, capillary temperature of 25 °C, and UV detection of 200 nm. (a, b, c, e) Extraction conditions: the running buffer of RF-MECC as for acceptor phase; extraction time, 15 min; extraction temperature, 90 °C; sample volume, 5.0 mL; salt concentration, 5.1 M; and stirring rate at moderate speed. The final concentrations of analytes were 2.0, 0.5, and 5.0 ng/mL for cyfluthrin, fenpropathrin, and tetramethrin, respectively. (d) Analytical conditions such as (a); the standards solution were diluted with methyl cyanide and then injected for 10 s with the height difference of 20 cm between the inlet end and the outlet end of capillary. The final concentrations of analytes were 20, 2.5, and 50 ng/mL for cyfluthrin, fenpropathrin, and tetramethrin, respectively.
Citation: Acta Chromatographica Acta Chromatographica 31, 3; 10.1556/1326.2018.00436