The effect of nitrites in foods and beverages still raises discussion due to the possible formation of harmful nitroso compounds. However, as most of these compounds in beer were not structurally characterized yet, the research about their toxicological relevance for consumers is limited. This study is focused on identification of the products formed by nitrite (or isotopically labeled nitrite ¹⁵N) reactions in beer using gas chromatography with tandem mass spectrometry. In total, 19 products were identified, and some of them were structurally characterized and confirmed by comparing retention indices and mass spectra of standard/synthesized compounds. Identified compounds were representatives of nitroso, nitro, oxime, and even cyano compounds. For the peaks which were not structurally identified, primary structural characteristics were also listed. Found products were further screened in 16 authentic beer samples which showed the apparent occurrence of found compounds in non-treated beers.

中文翻译：

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啤酒中亚硝酸盐相关反应产物的表征

由于可能形成有害的亚硝基化合物，亚硝酸盐在食品和饮料中的影响仍然引起讨论。然而，由于啤酒中的大多数这些化合物还没有结构特征，关于它们对消费者的毒理学相关性的研究是有限的。本研究的重点是鉴定亚硝酸盐（或同位素标记的亚硝酸盐¹⁵N) 使用气相色谱和串联质谱法在啤酒中进行反应。共鉴定出 19 种产物，其中一些产物通过比较标准/合成化合物的保留指数和质谱进行了结构表征和确认。鉴定的化合物是亚硝基、硝基、肟甚至氰基化合物的代表。对于未在结构上鉴定的峰，还列出了主要结构特征。在 16 个正宗啤酒样品中对发现的产品进行了进一步筛选，结果表明未处理啤酒中明显存在发现的化合物。