An atmospheric pressure laserspray ionization mass spectrometry (AP-LSI mini MS) has been developed and employed in the fast analysis of bacteria. Without using surfactants or any extracting methods, 21 foodborne bacteria from 12 genera were directly analyzed. Typical fingerprints of small molecules and lipids were detected and recognized in the mass spectra with high reproducibility. Furthermore, a supervised multivariate statistics method, orthogonal partial least squares (OPLS), was applied, and these bacteria could be differentiated at both genus and species levels. With improved performance in the future, AP-LSI mini MS could be a simple, effective, and fast approach for direct bacteria analysis on the field.

大气压激光喷雾电离质谱仪（AP-LSI mini MS）已被开发并用于细菌的快速分析。不使用表面活性剂或任何提取方法，直接分析了12个属的21种食源性细菌。在质谱中检测并识别出小分子和脂质的典型指纹图谱，具有很高的重现性。此外，采用了监督多元统计方法，正交偏最小二乘（OPLS），这些细菌可以在属和种水平上进行区分。随着将来性能的提高，AP-LSI mini MS可以成为一种简单，有效且快速的方法，用于现场细菌的直接分析。