Volume 41, Issue 5 (September 1996)
Thin-Layer Chromatography of Writing Inks—Quality Control Considerations
Quality control procedures for thin-layer chromotrography (TLC) are offered to increase reproducibility and dependability of results. During preparation of a TLC ink standard library, several types of inconsistencies were observed. Observations of more than 100 chromatograms of writing inks indicated the need for the institution of quality control procedures. Procedures were developed to ensure proper solvent selection, TLC plate selection, and proper photographic recording of TLC plates. Implementing quality control procedures in TLC enables the document examiner and forensic chemist to achieve these results.