Rapid Determination of Ethephon in Grapes by Hydrophilic Interaction Chromatography Tandem Mass Spectrometry

Ethephon analysis usually requires indirect and laborious method including a derivatization step before gas chromatography tandem mass spectrometry (GC-MS/MS) determination. In this paper, the described method is quick and based on simple procedure without any clean-up. After addition of ethephon D4 as surrogate, a methanolic extraction was performed. The determination is done by high performance liquid chromatography coupled to a tandem mass spectrometer (LC-MS/MS) in electrospray negative mode. The chromatographic separation was achieved on a hydrophilic interaction liquid chromatography (HILIC) column. This methodology significantly reduces the time of analysis to around 10 min for sample extraction and 10 min for determination. The analytical performance was evaluated with grape samples spiked at the limit of quantification, 50 µg kg