HS-SPME-GC-MS analyses of volatiles in plant populations – quantitating compound x individual matrix effects

Authors: BURZYNSKI-CHANG, ELIZABETH - Cornell University; RYONA, IMELDA - Cornell University; REISCH, BRUCE - Cornell University; GONDA, ITAY - Boyce Thompson Institute; FOOLAD, MAJID - Pennsylvania State University; Giovannoni, James; SACKS, GAVIN - Cornell University

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2018
Publication Date: 9/23/2018
Citation: Burzynski-Chang, E., Ryona, I., Reisch, B., Gonda, I., Foolad, M., Giovannoni, J.J., Sacks, G. 2018. HS-SPME-GC-MS analyses of volatiles in plant populations – quantitating compound x individual matrix effects. Molecules. 23:2436. doi.org/10.3390/molecules23102436
DOI: https://doi.org/10.3390/molecules23102436

Interpretive Summary: Gas chromatography – mass spectrometry is widely used as a means of measuring the presence and levels of volatile compounds contributing to fruit aroma which in turn contributes to flavor. The nature of extraction methods and the matrix in which the volatiles are isolated can contribute to measured levels thus impacting downstream characterization and analysis. Here we tested the degree to which these effects occurred in the context of populations of tomato or grape plants segregating for volatile traits and with different extraction solvents. We demonstrate that matrix composition can contribute to measured outcomes but use of internal standards can facilitate correction of these errors.

Technical Abstract: Headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–mass spectrometry (GC-MS) is widely employed for volatile analyses of plants, including mapping populations used in plant breeding research. Studies often employ a single internal surrogate standard, even when multiple analytes are measured, with the assumption that any relative changes in matrix effects among individuals would be similar for all compounds. We tested this assumption using individuals from two plant populations: an interspecific grape (Vitis spp.) mapping population (n = 140) and a tomato (Solanum spp.) recombinant inbred line (RIL) population (n = 148). Individual plants from the two populations were spiked with a cocktail of internal standards (n = 6, 9, respectively) prior to HS-SPME-GC-MS. Variation in the relative responses of internal standards indicated that Compound x Individual interactions exist but were different between the two populations. For the grape population, relative responses among pairs of internal standards varied considerably among individuals, with a maximum of 249% relative standard deviation (RSD) for the pair of [U13 C] hexanal and [U13 C] hexanol. However, in the tomato population, relative responses of internal standard pairs varied much less, with pairwise RSDs ranging from 8% to 56%. The approach described in this paper could be used to evaluate the suitability of using surrogate standards for HS-SPME-GC-MS studies in other plant populations.