Comparison of electrospray ionization and atmospheric pressure photoionization liquid chromatography mass spectrometry methods for analysis of ergot alkaloids from endophyte-infected sleepygrass (Achnatherum robustum).
Ergot alkaloids are mycotoxins with an array of biological effects. With this study, we investigated for the first time the application of atmospheric pressure photoionization (APPI) as an ionization method for LC-MS analysis of ergot alkaloids, and compared its performance to that of the more established technique of electrospray ionization (ESI). Samples of the grass Achnatherum robustum infected with the ergot producing Epichloë fungus were extracted using cold methanol and subjected to reserved-phase HPLC-ESI-MS and HPLC-APPI-MS analysis. The ergot alkaloids ergonovine and lysergic acid amide were detected in these samples, and quantified via external calibration. Validation parameters were recorded in accordance with ICH guidelines. A triple quadrupole MS operated in multiple reaction monitoring yielded the lowest detection limits. The performance of APPI and ESI methods was comparable. Both methods were subject to very little matrix interference, with percent recoveries ranging from 82% to 100%. As determined with HPLC-APPI-MS quantification, lysergic acid amide and ergonovine were extracted from an A. robustum sample infected with the Epichloë fungus at concentrations of 1.143±0.051 ppm and 0.2822±0.0071 ppm, respectively. There was no statistically significant difference between these concentrations and those determined using ESI for the same samples.
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Alan K
AK
Jarmusch
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Ashleigh M
AM
Musso
Department of Biology, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Tatsiana
T
Shymanovich
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Scott A
SA
Jarmusch
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Miranda J
MJ
Weavil
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Mary E
ME
Lovin
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Brandie M
BM
Ehrmann
Department of Biology, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Susanna
S
Saari
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 575 Stadium Mall Dr., West Lafayette, IN 47907, United States.
David E
DE
Nichols
Department of Biology, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States.
Stanley H
SH
Faeth
Department of Chemistry and Biochemistry, University of North Carolina Greensboro, PO Box 26170, Greensboro, NC 27402, United States. Electronic address: nadja_cech@uncg.edu.
Nadja B
NB
Cech
D001274:Atmospheric Pressure; D002853:Chromatography, Liquid / Q000379:methods; D060026:Endophytes / Q000737:chemistry*; D004876:Ergot Alkaloids / Q000032:analysis*; D006109:Poaceae / Q000382:microbiology*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D004876:Ergot Alkaloids
Achnatherum robustum; Atmospheric pressure photoionization; Electrospray ionization; Endophyte; Ergonovine; Ergot; Lysergic acid amide