对于静态和动态顶空分析,只有一个专用工具在PAL System使用,并且可以立即使用。即使是用于液体进样或固相微萃取 (SPME)的所有其他工具也可以用于其他方法,且无需任何硬件更改,使PAL System成为任何类型样品的真正多种进样方式设备
以及GC和GC-MS分析的在线样品前处理设备。
静态顶空分析(HS-GC)是最简单的方法。只需要少量的均化的样品制备,然后将液体或固体样品加入10或20 mL的顶空小瓶中,称重,并将盖好的小瓶放入PAL System的支架上。PAL顶空工作流程接管并最终进样到GC或GC-MS系统。
静态顶空分析适用于所有具有显著蒸气压的分析物。通常,挥发性有机化合物(VOCs)分析物的沸点高达250°C,包括自然和人为来源的分析物。美国环保局方法5021A列出了70多种化合物,主要是具有环境重要性的溶剂,这些化合物包含在本标准方法中[1]。
ITEX DHS工具的动态顶空分析(DHS)将被分析物的范围扩展到蒸汽压更低、沸点更高的分析物。
与静态顶空法不同,静态顶空法使用样品和上述顶空之间的平衡,动态法是一个更耗时的流程。将目标分析物连续地从样品中释放出,并在ITEX阱上收集,直到进行分析。
只有PAL System在同一台仪器上运行静态和动态方法。以前的仪器解决方案需要两台专用且占用空间的设备。
可提供多种吸附剂材料,包括标准Tenax TA/GR,以及Carbopack、Carboxen和Carbosive吸附剂。
ITEX DHS提供了固体、液体和气体样品中挥发性和半挥发性化合物的动态顶空富集。吸附剂材料被嵌入注射器针头的上部。该分析物捕集阱可进行 温控并在GC进样口快速升温进行热解析,完成进样后通过风扇进行室温冷却。
[1] [1] U.S. EPA, 2014. Method 5021A. Volatile Organic Compounds in Various Sample Matrices using Equilibrium Headspace Analysis. SW-846 Update V, Rev.2.
Analysis of flavors, pesticides, and biomarkers directly from complex food matrix using the automated Vacuum In-Tube Extraction (V-ITEX)
Extraction of volatile compounds is a widely used approach for analysis of foods and beverages. By the nature of gas phase sampling, the limiting factor for polar analytes are given by low vapor pressure or higher boiling points of semi-volatile compounds. These limitations can be overcome by sampling at decreased pressure levels using vacuum conditions. This has been shown in several publications using vacuum sampling techniques. In this study, a fully automated approach of Vacuum In-Tube Extraction (V-ITEX) is presented, a simple and fully automated technique using PAL system autosamplers. The application examples include flavors, fragrances, off-flavors, pesticides and biomarkers by extractions directly from the food sample matrix, such as Honey, Bee Wax, Cheese, Onions, Blood and Urine.
Presented by:
Pascal Fuchsmann, Head of Flavor Analytics Agroscope
Stefan Cretnik, Product Manager CTC Analytics AG
How to Develop a Method using In-tube Extraction (ITEX) for GC and GC/MS?
In this App Note we focused on in-tube extraction (ITEX) as a powerful alternative to classic purge & trap analysis. The approach is particularly well suited for the analysis of trace organic compounds with a wide range of volatilities. Due do the simplicity of the system, it can be applied successfully to the analysis of heavily loaded samples without the risk of cross contamination and permanent system failure.
A Comparison of ITEX Dynamic Headspace–GC/MS to other Enrichment Techniques for Analysis of Flavoring Compounds
The automated ITEX Dynamic Headspace unit demonstrated equivalent accuracy and precision when compared to purge and trap and overall was more sensitive than the other enrichment techniques. The ITEX unit allows for automated analysis and optimization of conditions which drastically reduces analyst’s time when compared to performing the experiments manually with the purge and trap without any reduction in sensitivity, accuracy and reproducibility.
Analysis of volatile compounds from honeys to differentiate plant and geographical origins
The analysis of volatile organic compounds (VOCs) is a faster approach to identify the honey’s origin than traditional methods, which is important for the quality control of honeys. In-tube extraction dynamic headspace (ITEX-DHS) is a fully automated microextraction technique, in which the enrichment of analytes takes place by repeated aspiring and dispensing of the sample headspace through a sorbent trap