(University of New England)
A small sample of leaf material (~0.02g) was collected from plants cultivated at the Australian Arid Lands Botanic Garden (Port Augusta, SA) by staff at the garden. Specimens were immediately placed in glass vials containing a small volume of MeOH and shipped to the lab where they were filtered and MeOH added to make up to ~ 1.5 mL. Specimens were then injected into the GC-MS for characterization.
Agilent GC System 7890A; inert MSD with triple-axis detector 7975C; Agilent HP-5MS column (30 m × 250μm× 0.25μm; He; 50 °C for 0 min, 5 °C/min to 260 °C, hold 2 min). To limit the impact of solvent-related peaks, peaks prior to a retention time of 3.5 min were not considered in analyses.
Spectra were matched to the NIST11 library and a small private Eremophila compound library maintained at the University of New England. The top 10 peaks were selected, and arithmetic (retention) indices (AI) calculated and compared to the NIST Webbook (http://webbook.nist.gov/chemistry/). An annotation was rejected if the AI (+/-2%) did not match published values for nonpolar column data. If the quality match of the spectra to the NIST11 or private library was under 80% the annotation was rejected. Where no published AI was available, a compound was accepted if the quality of the spectra match was 90% or over.