Developing a green LC method for the determination of the furocoumarins 5-MOP and 8-MOP in citrus oils using the Agilent 1290 Infinity LC

Lemon and orange oils were analyzed for the presence of the furocoumarins 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP) with the Agilent 1290 Infinity LC system. At 1000 bar, the total analysis time in reversed-phase (RP) liquid chromatography (LC) with acetonitrile and water as mobile phase components could be reduced to 4 min. In the frame work of green chromatography, and the present acetonitrile shortage, mobile phases constituted of water/methanol and water/ethanol were compared to water/acetonitrile. The influence of the nature of organic modifiers on selectivity and peak capacity was investigated. The figures of merit of the different methods were compared for the determination of 5-MOP in a lemon oil sample containing approximately 50 mg/kg. 8-MOP was not detected at the ppm level. The detection limit for both furocoumarins was approximately 1 mg/kg citrus oil. Authors Gerd Vanhoenacker, Frank David, and Pat Sandra Research Institute for Chromatography Kennedypark 26 B-8500 Kortrijk Belgium Bernd Glatz and Edgar Naegele Agilent Technologies R & D and Marketing GmbH and Co. KG Hewlett-Packard-Str. 8 76337 Waldbronn Germany Application Note Natural Products, Fragrances min 2 4 6 8 10 12 14 16 mAU