Volatome analysis approach for the taxonomic classification of tree exudate collection using Proton Transfer Reaction Time of Flight Mass Spectrometry

Abstract

Natural resins exude from trees as viscous liquids, which subsequently harden by evaporation and/or oxidation. Their compositions and textures are complex and vary during the solidification processes, producing a typical volatile fragrant fraction. Many techniques have been applied to the study of resins in order to obtain considerable chemical information but no exploratory work has been conducted using Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR‐ToF‐MS). For this reason its potential to rapidly obtain the Volatiles Organic Compounds (VOCs) mass profiles of several natural resins has been tested. A Partial Least Squares Discriminant Analysis (PLSDA) have been performed to classify all samples based on their species, family or order on the basis of the VOCs emission profiles of 31 natural resins derived from different tree species. The sensitivities and specificities obtained were higher than 95% whilst a correct classification was higher for family (94.23% on 7 classes) and order (94.12% on 6 classes), than that of species (89.06% on 31 classes). Finally confusion matrices based on PLSDA models were produced to observe and draw conclusions about non‐correct classifications. In our study we successfully determined the volatile profiles for 31 different tree natural resins assessing the possibility of correctly identify the taxonomic position of the trees by the analysis of their aromatic profiles. This preliminary study could lay down the bases for future studies on the VOC emissions of resins, by qualifying PTR‐ToF‐MS as a promising tool for a fast resin identification of complex matrix.

Trichoderma harzianum Volatile Organic Compounds Regulated by the THCTF1 Transcription Factor Are Involved in Antifungal Activity and Beneficial Plant Responses

“…A total of 129 and 130 VOCs were detected at five and nine days, respectively, in the range of measured masses (mass protonated range m / z = 20–300) after the subtraction of peaks associated with the PTR-MS ion source and their isotopes. VOCs’ putative identification is reported in Supplementary Table S2 [ 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]. Overall, all samples’ released VOCs were blends composed of similar compounds, but in different proportions.…”

Correlation between VOC fingerprinting and antimicrobial activity of several essential oils extracted by plant resins against A. tumefaciens and P. savastanoi

“…In this study, the volatile profile analysis of each essential oil was performed with PTR‐ToF‐MS, a powerful instrument able to screen the entire VOC profile, with short response times, high mass resolution and virtually without an upper mass limit . A total of 142 different volatile compounds was identified by VOC analysis of the twelve essential oils extracted from plant resins.…”

“…In this study, extraction was performed using the hydrodistillation method with water as the solvent. A commercial PTR‐MS 8000 (Ionicon Analytik, Innsbruck, Austria) instrument, which is useful for achieving the whole mass spectra from several matrices, was used to assess the volatile profile for the collection of different essential oil samples. The advantages and disadvantages of this tool, as well as the details of its operation are reported in Blake et al and Taiti et al The analysis was carried out following a similar methodology previously reported by Taiti et al Briefly, a glass vial (15 ml) containing 2 µl of oil sample was placed in a glass jar (3/4 L) and covered with glass lid fitted with two holes.…”

Benzoin Resin: An Overview on Its Production Process, Phytochemistry, Traditional Use and Quality Control

“…Furthermore, methods of distinguishing different resins have been developed simultaneously. Taiti et al used proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) to classify different resins based on their volatile organic compound emission profiles [ 61 ]. Wei et al established a rapid and nondestructive method for identification of six resins by near-infrared reflectance spectroscopy (NIR).…”