Identification of paper by stationary phase performance

• Autor(a) principal: Smith, Michael John
• Data de Publicação: 2014
• Outros Autores: Gray, Fiona M., Vale, Ilda C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/32002
• topic: Analytical Chemistry; Laboratory Instruction; Forensic Chemistry; First-Year Undergraduate/General; Hands-On Learning/Manipulatives; High School/Introductory Chemistry; Ciências Naturais::Ciências Químicas; Science & Technology; Social Sciences

Paper is an extraordinary example of a composite engineering material with practical use in a huge variety of applications. Since its invention in China there have been many alterations to manufacturing techniques, component formulation and surface finishing, but the essential characteristics of the product have not changed greatly. The objective of this experiment is to demonstrate that the chromatographic performance of paper as a stationary phase may be used to distinguish between externally-similar materials. The procedure developed is so simple that even students with little exposure to practical chemistry and limited chemical knowledge can understand the essential content. Because of the ubiquitous nature of paper, it is often recovered from crime scenes as evidence for analysis. However, the variety of sources and the mechanical or chemical properties often make demonstration of unequivocal correlation between “questioned” and “known” or “reference” samples a complex task. Introducing the practical session as a crime scene investigation, and presenting the laboratory exercise as an accessible forensic technique for paper identification, adds an exciting dimension to the practical experience for young people.