Methylhexanamine is not detectable in Pelargonium or Geranium species and their essential oils: A multi‐centre investigation

In an earlier study, we developed two sensitive and reliable procedures for gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of methylhexaneamine (MHA) in P. graveolens plant materials and volatile oils. None of the analyzed plant materials or oils showed any detectable levels of MHA which was further substantiated by high resolution liquid chromatography-quantum time of flight-mass spectrometry (LC-QTOF-MS) analysis with a limit of detection of 10 ppb. However, other laboratories (two studies) reported the presence of MHA in some samples of P. graveolens and pelargonium oil acquired by the investigators from China. Because of the controversy of whether Pelargonium species or pelargonium oil contains MHA, it was recommended that splits of multiple samples be analyzed by different laboratories. In this investigation, multiple plant materials and oil samples were collected from around the world. These samples were submitted to four different sites for analysis. All sites adopted a similar extraction method. All the analysis sites used LC-MS/MS or LC-QTOF-MS and detection limit was set close to the 10 ng/mL as previously reported. A total of 18 plant samples belonging to 6 different Pelargonium species and 9 oils from different locations around the world were split among 4 different analytical laboratories for analysis (each lab received the same samples). None of the laboratories detected MHA in any of the samples at or around the 10 ppb detection level of the procedure used. Copyright © 2014 John Wiley & Sons, Ltd.