Among N-((2-substituted)benzyl)phenylethanamines, N-(2-hydroxybenzyl)phenylethanamines are a special type of compounds which are thermolabile and degrade in the course of analysis by means of gas chromatography–mass spectrometry (GC–MS). This can lead to substantial errors, in the identification of legally controlled compounds of this series containing methoxy groups at positions 2 and 5 of the benzene ring of the phenylethyl fragment by GC–MS, which is commonly used in forensic and toxicological laboratories. Exemplified by the five isomeric 2-(dimethoxyphenyl)-N-(2-hydroxybenzyl)ethanamines, it was shown that their derivatization with trifluoroacetic anhydride (same as in the case of the N-(2-methoxybenzyl)-, N-(2-fluorobenzyl)-, N-(2-chlorobenzyl)-, and N-(2-bromobenzyl)substitutes phenylethanamines [NBOMe, NBF, NBCl, and NBBr, respectively] series described earlier) results in only one product, N-monosubstituted derivative, for each positional isomer within a series, which makes it possible to reliably identify each compound by the GC–MS method. In addition, chromatographic conditions for sufficient separation of trifluoroacetyl derivatives of these positional isomers of the NBOH series in 25 min are proposed, which is an important aspect for analysis in forensic laboratories engaged in the determination of narcotic drugs and new psychoactive substances. As an alternative approach, a method for identifying positional isomers of the NBOH series by the high-performance liquid chromatography–high-resolution mass spectrometry (HPLC-HRMS) method without derivatization is proposed.

中文翻译：

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使用色谱和质谱方法鉴定 N-(2-羟基苄基)-2-(二甲氧基苯基)乙胺（NBOH 系列）的不耐热位置异构体

在N -((2-取代)苯甲基)苯乙胺中，N- (2-羟基苯甲基)苯乙胺是一种特殊类型的化合物，其不耐热并且在气相色谱-质谱(GC-MS)分析过程中会降解。 。这可能会导致在通过法医和毒理学实验室常用的 GC-MS 鉴定该系列在苯乙基片段苯环的 2 和 5 位含有甲氧基的合法受控化合物时出现重大错误。以五种异构体2-(二甲氧基苯基)-N- ( 2-羟基苄基)乙胺为例，结果表明它们与三氟乙酸酐的衍生化(与N- (2-甲氧基苄基)-、N- (2 -氟苯甲基)-、N -(2-氯苯甲基)-和N -(2-溴苯甲基)取代苯乙胺[分别是前面描述的NBOMe、NBF、NBCl和NBBr]系列)仅产生一种产物，N-单取代衍生物，对于系列中的每个位置异构体，这使得可以通过 GC-MS 方法可靠地识别每种化合物。此外，还提出了在25分钟内充分分离NBOH系列这些位置异构体的三氟乙酰基衍生物的色谱条件，这对于从事麻醉药品和新型精神活性物质测定的法医实验室分析来说是一个重要方面。作为一种替代方法，提出了一种无需衍生化的高效液相色谱-高分辨率质谱（HPLC-HRMS）方法来鉴定NBOH系列的位置异构体。