title: Investigation of Pyrrolizidine Alkaloids in Plant Material by Means of Positive Ion and Negative Ion Chemical Ionization GC-MS.
authors.affiliation: Laboratory of Pharmacognosy, State University Groningen, Antonius Deusinglaan 2, 9713 AW Groningen, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Hendriks
authors.forename: H J
authors.initials: HJ
authors.lastname: Huizing
authors.forename: A P
authors.initials: AP
authors.lastname: Bruins