Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
Analyst. 2011 Aug 7;136(15):3091-7. doi: 10.1039/c0an00940g. Epub 2011 Jun 27.
Low temperature plasma mass spectrometry (LTP-MS) was employed to detect fatty acid ethyl esters (FAEE) from bacterial samples directly. Positive ion mode FAEE mass spectrometric profiles of sixteen different bacterial samples were obtained without extraction or other sample preparation. In the range m/z 200-300, LTP mass spectra show highly reproducible and characteristic patterns. To identify the FAEE's associated with the characteristic peaks, accurate masses were recorded in the full scan mode using an LTQ/Orbitrap instrument, and tandem mass spectrometry was performed. Data were examined by principal component analysis (PCA) to determine the degree of differentiation possible amongst different bacterial species. Gram-positive and gram-negative bacteria are readily distinguished, and 11 out of 13 Salmonella strains show distinctive patterns. Growth media effects are observed but do not interfere with species recognition based on the PCA results.
低温等离子体质谱（LTP-MS）被用于直接检测细菌样本中的脂肪酸乙酯（FAEE）。无需提取或其他样品制备，就可以得到十六个不同细菌样本的正离子模式 FAEE 质谱图谱。在 m/z 200-300 范围内，LTP 质谱显示出高度重现性和特征性的模式。为了鉴定与特征峰相关的 FAEE，使用 LTQ/Orbitrap 仪器在全扫描模式下记录精确质量，并进行串联质谱分析。通过主成分分析（PCA）检查数据，以确定不同细菌种类之间可能存在的分化程度。革兰氏阳性菌和革兰氏阴性菌很容易区分，13 株沙门氏菌中有 11 株显示出独特的模式。观察到生长培养基的影响，但基于 PCA 结果，不会干扰对物种的识别。
