Ultrasound-assisted dispersive liquid-liquid microextraction coupled withHPLC-DAD for simultaneous measurement of folic acid and 5-methyltetrahydrofolate

Ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) has been proposed for the simultaneous determination of 5-methyltetrahydrofolate and folic acid levels in human serum samples. High performance liquid chromatography (HPLC) coupled with photodiode array detection (DAD) was employed to analysis the extraxtants. One-factor-at-a-time procedures were used to determine the optimal conditions for extraction recovery, including pH of sample solution, type and volume of extraction solvent, type and volume of disperser solvent, ultrasound temperature and time, centrifugation time, and ionic strength. As a result of optimized extractions, the relative standard deviation (RSDs) of the analyses was less than 9 % (n = 3) and the detection limit was 10.8- 32.9 ng mL-1. Recoveries for 5-methyltetrahydrofolate and folic acid were in the ranges of 65–73 %. Recoveries for 5-methyltetrahydrofolate and folic acid were in the ranges of 65–73 %. UA-DLLME–HPLC was used successfully for the simultaneous determination of 5-methyltetrahydrofolate and folic acid in human serum.

Ultrasound-assisted dispersive liquid-liquid microextraction coupled withHPLC-DAD for simultaneous measurement of folic acid and 5-methyltetrahydrofolate Keywords:

5-methyltetrahydrofolate , folic acid , serum , HPLC.