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o-Phthalaldehyde or ortho-phthalaldehyde (OPA) is the chemical compound with the formula C6H4(CHO)2.
P 1817 (OTTO) o-Phthaldehyde, 99% Cas no 643-79-8 - used in precolumn derivatization of amino acids for HPLC separation. P 1817 (OTTO) o-Phthaldehyde, 99% Cas no 643-79-8 - used for flow cytometric measurements of protein thiol groups.