Harmful azo colorants in leather. Determination based on their cleavage and extraction of corresponding carcinogenic aromatic amines using modern extraction techniques.

Research output: Contribution to journalArticle


This study concerns the possibilities of using microwave-assisted extraction (MAE) or supercritical fluid extraction (SFE) for detection of harmful azo colorants in leather. After degreasing of the leather sample with SFE there follows a reductive cleavage of the azo colorants to their corresponding aromatic amines in the MAE or SFE equipment. The aromatic amines are subsequently extracted using either MAE or SFE and then finally determined by liquid chromatography with diode-array detection. The results have been compared with recoveries obtained using the German DIN method 53316. This standard method, based on conventional solvent extraction, is used in several European countries. Overall much better recoveries were obtained using MAE or SFE. With both MAE and SFE the amine recoveries of spiked leather samples were generally above 50%. The average recoveries were 62% for MAE and 60% for SFE (solvent collection) compared to 24% with the DIN method. For genuine leather samples the recoveries decreased, especially for benzidine. In this case the average values for MAE, SFE and DIN were 54, 38 and 19%, respectively. The quantification limits in leather samples using MAE or SFE were below 1 mg/kg for all amines investigated. The within-laboratory precision was generally better than 10%, varying somewhat with the analyte considered. With the proposed methodology, the amount of hazardous organic solvents used could be decreased and the sample throughput increased with at least a factor of two with less manual handling compared to the DIN method.


  • Cecilia Sparr Eskilsson
  • Richard Davidsson
  • Lennart Mathiasson
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Analytical Chemistry


  • Azo dyes, aromatic, Amines
Original languageEnglish
Pages (from-to)215-227
JournalJournal of Chromatography A
Issue number2
Publication statusPublished - 2002
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Analytical Chemistry (S/LTH) (011001004)