Quantification of staling aldehydes from wort and beer requires sensitive instrumental analysis. In the brewing industry, this is for the most part accomplished by gas chromatography-mass spectrometry (GC-MS) using headspace solid-phase microextraction (HS-SPME) and on-fiber derivatization (OFD) with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA). With respect to lipid oxidation products (e.g., (E)-2-nonenal) and minor Strecker aldehydes (e.g., methional), the sensitivity of GC-EI-MS might not be sufficient to ensure reliable quantification and long-term stability regarding method performance. To overcome these problems, an elaborate gas chromatography-electron impact-tandem mass spectrometry (GC-EI-MS/MS) methodology was implemented. GC-EI-MS/MS improved sensitivity and reduced matrix effects resulting from overlapping PFBHA-oximes (PFBOs). It enabled reliable quantification of 15 selected aldehydes in different matrices (wort, beer) across a wide concentration range (0.01 − 1000 µg/L). Extensive method validation and long-term stability testing proved excellent method performance. Lastly, direct comparison of GC-EI-MS/MS and GC-EI-MS revealed that the quantification of low abundant aldehydes via GC-EI-MS/MS is more reproducible and that lower limits of quantification were achieved.

麦芽汁和啤酒中陈旧醛的定量需要灵敏的仪器分析。在酿造业中，这大部分是通过使用顶空固相微萃取（HS-SPME）的气相色谱-质谱（GC-MS）和O-（2,3， 4,5,6-五氟苄基）羟胺（PFBHA）。关于脂质氧化产物（例如，（E）-2-壬烯醛）和少量Strecker醛（例如甲硫基），GC-EI-MS的灵敏度可能不足以确保可靠的定量和方法性能的长期稳定性。为了克服这些问题，实施了详细的气相色谱-电子碰撞串联质谱分析（GC-EI-MS / MS）方法。由于重叠的PFBHA-肟（PFBO），GC-EI-MS / MS改善了灵敏度并降低了基质效应。它能够在宽浓度范围（0.01-1000 µg / L）中可靠地定量分析不同基质（麦芽汁，啤酒）中的15种选定醛。广泛的方法验证和长期稳定性测试证明了其出色的方法性能。最后，