title: Dating of seals produced with stamp-pad ink using gas chromatography method.
abstract: Seals are often placed on important documents, and determining the date when a seal was affixed can be important to assess the authenticity of a document. In this study, thirty-seven different brands of stamp-pad inks and three different types of paper were used to make diachronic samples of the seals. The volatile components of stamp-pad ink were determined, and the stamp-pad ink was classified by gas chromatography with a flame ionization detector. Calibration curves were created to show the relationship between the content of volatile stamp-pad ink components and the age of stamp-pad ink entries stored under natural aging, UV-induced aging, and heating aging conditions. The experimental results showed that GC was useful in the analysis of stamp-pad ink and applicable for determining the relative age of stamp-pad ink entries in some cases where the seal was placed on the document within 3 months.
authors.affiliation: Department of Document Examination, China Criminal Police University, No. 83 Tawan Street, Shenyang City, 110854, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Li
keywords: dating of documents; dating of seals; document examination; forensic science; gas chromatography method; stamp-pad ink