The seeds of grass pea (Lathyrus sativus L.), a drought tolerant crop, were analysed for quantitative determination of the free amino acids p-N-oxalyl-t-e,3-diaminopropionic acid (beta-ODAP), homoarginine and asparagine by a simple and fast capillary electrophoretic method. In boric acid (80 mM, pH 8.0) running buffer system, not only were a and p-ODAP successfully separated, but also an efficient sample stacking was achieved during hydrodynamic sample introduction. The validated method was used for quantification of p-ODAP, homoarginine and asparagine in seed extracts of 52 Lathyrus local landraces from various regions of Turkey and one released cultivar. The concentration ranges of amino acids were found as 0.211.27% (w/w) for homoarginine, 0.10-0.87% (w/w) for beta-0DAP and 0.006-0.47% (w/w) for asparagine. A positive correlation between homoarginine and 13-0DAP quantities in seeds of 53 Lathyrus local landraces was shown to exist (r2 = 0.649). (C) 2013 Elsevier Ltd. All rights reserved.