U.S. National Fish and Wildlife Forensics Laboratory, 1490 East Main Street, Ashland, OR, 97520-1310, USA.
Rapid Commun Mass Spectrom. 2014 Feb 15;28(3):281-9. doi: 10.1002/rcm.6779.
It is important for the enforcement of the CITES treaty to determine whether agarwood (a resinous wood produced in Aquilaria and Gyrinops species) seen in trade is from a plantation that was cultivated for sustainable production or was harvested from natural forests which is usually done illegally.
We analyzed wood directly using Direct Analysis in Real Time (DART™) ionization coupled with Time-of-Flight Mass Spectrometry (TOFMS). Agarwood was obtained from five countries, and the collection contained over 150 samples. The spectra contained ions from agarwood-specific 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones as well as many other ions. The data was analyzed using either kernel discriminant analysis or kernel principal component analysis. Probability estimates of origin (wild vs cultivated) were assigned to unknown agarwood samples.
Analysis of the DART-TOFMS data shows that many of the chromones found in cultivated and wild agarwood samples are similar; however, there is a significant difference in particular chromones that can be used for differentiation. In certain instances, the analysis of these chromones also allows inferences to be made as to the country of origin. Mass Mountaineer™ software provides an estimate of the accuracy of the discriminate model, and an unknown sample can be classified as cultivated or wild. Eleven of the thirteen validation samples (85%) were correctly assigned to either cultivated or wild harvested for their respective geographic provenance. The accuracy of each classification can be estimated by probabilities based on Z scores.
The direct analysis of wood for the diagnostic chromones using DART-TOFMS followed by discriminant analysis is sufficiently robust to differentiate wild from cultivated agarwood and provides strong inference for the origin of the agarwood.
为了执行《濒危野生动植物种国际贸易公约》，确定贸易中出现的沉香（一种在沉香属和拟沉香属中产生的树脂木材）是来自可持续生产的种植园还是来自通常是非法采伐的天然林，这一点非常重要。
我们使用实时直接分析（DART ™）与飞行时间质谱（TOFMS）耦合的方法直接分析木材。沉香来自五个国家，采集的样本超过 150 个。该光谱包含了沉香特有的 5,6,7,8-四氢-2-（2-苯乙基）色酮以及许多其他离子的离子。使用核判别分析或核主成分分析对数据进行分析。对未知沉香样本的起源（野生与种植）进行概率估计。
DART-TOFMS 数据分析表明，种植和野生沉香样本中发现的许多色酮相似；然而，某些可以用于区分的特定色酮存在显著差异。在某些情况下，这些色酮的分析也可以推断出原产国。Mass Mountaineer ™ 软件提供了判别模型准确性的估计，并且可以将未知样本分类为种植或野生。在其各自的地理起源中，十三份验证样本中有十一份（85%）被正确地分配为种植或野生采集。每种分类的准确性都可以基于 Z 分数的概率进行估计。
使用 DART-TOFMS 对木材进行诊断色酮的直接分析，然后进行判别分析，足以区分野生和种植沉香，并为沉香的来源提供强有力的推断。
