论文部分内容阅读
引言捕集和富集挥发性化合物近来已成为制备试样的一种标准方法,但很少用以取得法庭物证。在文献报导的几乎所有应用中,都是将小量挥发性化合物捕集在过量的吸附剂上,但在物证中挥发物的量很容易超过吸附剂的容量,使试样失去代表性。法庭分析工作者可以根据由下列四个参数的排列组合而得到的十六种情况来设计、使用和评价试样中挥发物的富集方法: 1.试样是由动态的“吹洗和捕集”还是由静态扩散来富集? 2.吸附剂容量是否足以定量捕集所有挥发性化合物?
Introduction Capture and enrichment of volatile compounds has recently become a standard method of preparation of samples, but rarely used to obtain forensic evidence. In almost all applications reported in the literature, a small amount of volatile compounds are trapped on an excess of adsorbent, but the amount of volatiles in the material evidence easily exceeds the capacity of the adsorbent to render the sample unrepresentative. Forensic analysts can design, use and evaluate methods for the enrichment of volatiles in samples based on a combination of the following four parameters: 1. Samples are prepared by dynamic “purging and catching Set ”is still enriched by static diffusion? 2. Is adsorbent capacity enough to capture all volatile compounds quantitatively?