Nelson S D, Vaishnav Y, Kambara H, Baillie T A
Biomed Mass Spectrom. 1981 Jun;8(6):244-51. doi: 10.1002/bms.1200080604.
The mass spectra of several thioether conjugates of the widely used analgesic, acetaminophen (4'-hydroxyacetanilide), have been recorded under various ionization conditions. Conjugates were obtained from both in vitro and in vivo sources and purified by high performance liquid chromatography. Some standards were chemically synthesized. Of the thioethers examined, only the methylthio and mercapturic acid conjugates provided parent ions under electron impact conditions. In the chemical ionization mode, using isobutane as the reagent gas, the cysteinyl conjugate gave a pseudomolecular ion as well, although relatively large quantities (10-20 micrograms) of this amino acid adduct were required. Because of the highly polar nature and thermal instability of the cysteinyl and glutathionyl conjugates, these two thioethers were most successfully analyzed by field desorption techniques. Field desorption mass spectrometry was well suited for direct analysis of these two adducts where prominent [M]+, [MH]+ or [M + Na]+ ions were observed. Furthermore, by application of the field desorption/collision induced dissociation and linked (B/E) scan technique, structurally informative fragmentation patterns were generated. In addition, field desorption mass spectrometry was used successfully to characterize the glucuronide conjugate of acetaminophen but not the sulfate conjugate.
在多种电离条件下记录了广泛使用的镇痛药对乙酰氨基酚（4'-羟基乙酰苯胺）的几种硫醚缀合物的质谱。缀合物来自体外和体内来源，并通过高效液相色谱法纯化。一些标准品是化学合成的。在所研究的硫醚中，只有甲硫基和硫醚氨酸缀合物在电子轰击条件下产生母离子。在化学电离模式下，使用异丁烷作为反应气，半胱氨酰缀合物也产生了准分子离子，尽管需要相对大量（10 - 20微克）的这种氨基酸加合物。由于半胱氨酰和谷胱甘肽缀合物具有高度极性和热不稳定性，这两种硫醚最成功地通过场解吸技术进行分析。场解吸质谱非常适合直接分析这两种加合物，观察到了明显的[M]+、[MH]+或[M + Na]+离子。此外，通过应用场解吸/碰撞诱导解离和串联（B/E）扫描技术，产生了具有结构信息的碎片模式。此外，场解吸质谱成功地用于表征对乙酰氨基酚的葡糖醛酸缀合物，但不能表征硫酸酯缀合物。
