Separation and quantification of histamine and N^τ‐methylhistamine in brain extracts

Histamine and its Nτ‐methyl derivative can be separated from perchloric acid extracts of rat brain by high performance liquid chromatography on a C18 column under isocratic conditions eluting with 0.1 M sodium phosphate buffer containing 0.19 mM sodium dodecyl sulphate and 25% methanol. Using electrochemical detection, histamine and Nτ‐methylhistamine can be detected at levels of less than 40 pg/μL tissue extract (<1 pmol). The retention times for histamine and Nτ‐methylhistamine were 15 min and 23 min, respectively, at a flow rate of 1.2 mL/min, and both compounds eluted as acceptably sharp peaks. The concentrations of histamine and Nτ‐methylhistamine in brain from seven‐day‐old rats were found to be very similar to those obtained by other analytical procedures. Copyright © 1990 John Wiley & Sons, Ltd.