Roze Ludmila V, Beaudry Randolph M, Linz John E
Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, USA.
Methods Mol Biol. 2012;944:133-42. doi: 10.1007/978-1-62703-122-6_9.
Here, we describe a solid-phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) analytical approach that identifies and analyzes volatile compounds in the headspace above a live fungal culture. This approach is a sensitive, solvent-free, robust technique; most importantly from a practical standpoint, this approach is noninvasive and requires minimal sample handling. Aliquots of liquid fungal cultures are placed into vials equipped with inert septa and equilibrated at a constant temperature, and headspace gases are sampled using an SPME fiber inserted through the septum into the headspace above the fungal culture for a standardized period of time. The outer polymer coating of a fused silica fiber absorbs volatiles from the headspace; the volatiles are then desorbed in the hot GC inlet and chromatographed in the usual manner. The separated compounds are subsequently identified by mass spectrometry. All steps in volatile profiling of a single sample from volatile sorption on a fiber to obtaining a list of volatiles can take as little as 15 min or can be extended to several hours if longer sorption is required for compounds present at very low levels and/or have low rates of diffusion.
在此，我们描述了一种固相微萃取 - 气相色谱/质谱联用（SPME - GC/MS）分析方法，用于识别和分析活真菌培养物上方顶空中的挥发性化合物。这种方法是一种灵敏、无溶剂且稳健的技术；从实际应用角度来看，最重要的是，该方法是非侵入性的，且所需的样品处理极少。将液体真菌培养物的等分试样放入配有惰性隔垫的小瓶中，并在恒定温度下平衡，然后使用一根SPME纤维通过隔垫插入真菌培养物上方的顶空区域，在标准时间段内对顶空气体进行采样。熔融石英纤维的外部聚合物涂层会从顶空中吸收挥发性物质；然后挥发性物质在热的气相色谱进样口中解吸，并以常规方式进行色谱分析。随后通过质谱法对分离出的化合物进行鉴定。从纤维上挥发性物质的吸附到获得挥发性物质列表，单个样品挥发性分析的所有步骤最短只需15分钟，如果对于极低含量和/或扩散速率低的化合物需要更长的吸附时间，则可延长至数小时。
