1-Piperazineethanesulfonic acid, 4-(2-hydroxyethyl)- 4-(2-Hydroxyethyl)-1-piperazineethane sulfonic acid 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid 4-(2-Hydroxyethyl)piperazin-1-ylethanesulphonic acid 5-23-02-00379 (Beilstein Handbook Reference) 7365-45-9 75277-39-3 BRN 0883043 EINECS 230-907-9 HEPES N-2-Hydroxyethylpiperazine N',2'-ethanesulfonic acid N-2-Hydroxyethylpiperazine-N'-ethanesulfonate N-2-Hydroxyethylpiperazine-N'-ethanesulfonic acid N-2-Hydroxyethylpiperazine-N-ethane sulfonic acid NSC 166663