Fluorometric Determination of Artemisinin Using the Pyronin B–Microperoxidase-11 System

Resumo

A sensitive, rapid, and simple fluorimetric procedure for the determination of artemisinin in a concentration range of 0.1–7 μM was developed with the use of microperoxidase-11 as a peroxidase biomimetic (RSD = 0.8% at LOQ, n = 5; LOD = 7.1 nM (3s₀)). The determination is based on the fluorescence quenching of the cationic xanthene dye pyronin B (Stern–Volmer quenching constant, 0.101 μM^–1) in the presence of microperoxidase-11. The procedure was tested in the analysis of a biologically active additive based on an Artemisia annua wormwood extract. The correctness of the results of the fluorimetric determination of artemisinin in a biologically active dietary supplement was confirmed by HPLC–mass spectrometry. The use of oligopeptide microperoxidase-11 instead of heme-containing proteins (hemoglobin, cytochrome c, and horseradish peroxidase) made it possible to shorten the duration of artemisinin determination by a factor of 2 with the retention of sensitivity and selectivity.