Determination of alkaloids in onion nectar by micellar electrokinetic chromatography

SOTO VARGAS, CAROLINA; JOFRÉ, VIVIANA; CLAUDIO GALMARINI; SILVA, MARÍA FERNANDA

ELECTROPHORESIS

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2016

0173-0835

Nectar is the most important floral reward offered by plants to insects.Minor componentssuch as alkaloid compounds in nectar affect bee foraging, with great influence in seedproduction. CE is an advantageous tool for the analysis of unexplored samples such asonion nectar due to the limited amounts of samples. Considering the importance of thesecompounds, a simultaneous determination of nicotine, theophylline, theobromine, caffeine,harmaline, piperine in onion nectar byMEKC-UV is herein reported. The extractionof alkaloid compounds in nectar was performed by SPE using a homemade miniaturizedcolumn (C18). Effects of several important factors affecting extraction efficiency as wellas electrophoretic performance were investigated to acquire optimum conditions. Underthe proposed conditions, the analytes can be separated within 15 min in a 50 cm effectivelength capillary (75 m id) at a separation voltage of 20 kV in 20 mmol/L sodiumtretraborate, 100 mmol/L SDS. The amount of sample requirement was reduced up to2000 times, when compared to traditional methods, reaching limits of detection as low as0.0153 ng/L. For the first time, this study demonstrates that there are marked qualitativeand quantitative differences in nectar alkaloids between open pollinated and male sterilelines (MSLs) and also within MSLs.