A highly sensitive HPLC method for determination of nanomolar concentrations of dipicolinic acid, a characteristic constituent of bacterial endospores

J Microbiol Methods. 2007 Aug;70(2):319-27. doi: 10.1016/j.mimet.2007.05.008. Epub 2007 May 21.


A high-performance liquid chromatographic method with indirect fluorescence detection has been developed for quantification of dipicolinic acid, a major constituent of bacterial endospores. After separation on a reversed-phase column, a post-column reagent of sodium acetate at 1 mol l(-1) with 50 micromol l(-1) terbium chloride was added for complexation of dipicolinic acid. Terbium monodipicolinate complexes formed were quantified by measuring the fluorescence emission maximum at 548 nm after excitation with UV light at 270 nm wavelength. Parameters of post-column complexation were optimized to achieve a detection limit of 0.5 nmol DPA l(-1), corresponding to about 10(3) Desulfosporosinus orientis endospores per ml. The method was applied to the analysis of spore contamination in tuna and for estimating the endospore numbers in marine sediments.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromatography, High Pressure Liquid / methods*
  • Geologic Sediments / microbiology
  • Peptococcaceae / chemistry
  • Picolinic Acids / analysis*
  • Sensitivity and Specificity
  • Sodium Acetate / metabolism
  • Spores, Bacterial / chemistry*
  • Terbium / metabolism
  • Tuna / microbiology


  • Picolinic Acids
  • Terbium
  • Sodium Acetate
  • terbium chloride
  • dipicolinic acid