Hollow fiber-based liquid phase microextraction combined with HPLC for the simultaneous determination of two pyrimidines in Alysicarpus vaginalis (L.) DC.

Abstract

A simple, inexpensive and efficient three phase hollow fiber liquid phase microextraction technique combined with HPLC was used for the simultaneous determination of uracil and thymine in Alysicarpus vaginalis (L.) DC. Different factors affecting the hollow fiber liquid phase microextraction procedure were investigated and optimized. The optimized extraction conditions were as follows: 1-octanol as the organic solvent, pH_donor = 9.5, pH_acceptor = 3.0, 600 rpm stirring speed, 50 min extraction time, and without addition of salt. Under these conditions, the value of the enrichment factor for uracil and thymine was 48.2 and 43.6, respectively. Calibration curves showed good linearity (r > 0.999) within the test ranges. The limit of detection was 8.2 ng mL⁻¹ and 10.7 ng mL⁻¹, respectively and the intra- and inter-day RSDs were no more than 9.6%. The content of uracil and thymine in Alysicarpus vaginalis (L.) DC. was 0.106 μg g⁻¹ and 0.132 μg g⁻¹, respectively. The method was applied successfully for the simultaneous determination of uracil and thymine in Alysicarpus vaginalis (L.) DC.