Thin-layer and gas chromatographic deterimination of alpha, epsilon- diaminopimelic acid in Escherichia coli

Both thin-layer (TLC) and gas-liquid chromatographic (GLC) methods are described for determining α,ε-diaminopimelic acid (DAP) in Escherichia coli cell hydrolyzates. The TLC method is both rapid and sensitive whereas the GLC technique is extremely sensitive but more time-consuming. In the latter method, DAP is converted to the trifluoroacetylethylpimelate derivative and then detected by using an electron capture detector. The particular strain of E. coli studied was found to contain 0.68% DAP.