The proportional content of the phenylpropanoid monomeric units (4-hydroxyphenyl (H), guaiacyl (G), and syringyl (S)) in lignin is of paramount importance in germ plasm screening and for evaluating the results of plant breeding and genetic engineering. This content is usually determined using a tedious and slow (2 days/sample) method involving derivatization followed by reductive cleavage (DFRC) combined with GC/MS or NMR analysis. We report here a fast mass spectrometric method for the determination of the monomer content. This method is based on the fast pyrolysis of a lignin sample inside the ion source area of a linear quadrupole ion trap mass spectrometer. The evaporated pyrolysis products are promptly deprotonated via negative-ion mode atmospheric pressure chemical ionization ((-)APCI) and analyzed by the mass spectrometer to determine the monomer content. The results obtained for the wild-type and six genetic variants of poplar were consistent with those obtained by the DFRC method. However, the mass spectrometry method requires only a small amount of sample (50 μg) and the use of only small amounts of three benign chemicals, methanol, water, and ammonium hydroxide, as opposed to DFRC that requires substantially larger amounts of sample (10 mg or more) and large amounts of several hazardous chemicals. Furthermore, the mass spectrometry method is substantially faster (3 min/sample), more precise, and the data interpretation is more straightforward as only nine ions measured by the mass spectrometer are considered.

中文翻译：

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通过快速热解/大气压化学电离质谱法快速测定杨树遗传变体的木质素单体组成。

木质素中苯丙烷单体单元（4-羟基苯基 (H)、愈创木酰基 (G) 和丁香基 (S)）的比例含量在种质筛选和评估植物育种和基因工程的结果中至关重要。该含量通常使用繁琐且缓慢（2 天/样品）的方法进行测定，包括衍生化，然后是还原裂解 (DFRC)，并结合 GC/MS 或 NMR 分析。我们在这里报告了一种用于测定单体含量的快速质谱方法。该方法基于线性四极杆离子阱质谱仪离子源区域内木质素样品的快速热解。蒸发的热解产物通过负离子模式大气压化学电离 ((-)APCI) 迅速去质子化，并由质谱仪分析以确定单体含量。野生型和 6 种杨树遗传变异的结果与 DFRC 方法获得的结果一致。然而，与需要大量样品（10毫克或更多）和大量的几种危险化学品。此外，质谱方法显着更快（3 分钟/样品）、更精确、