title: Semi-xylenol orange and its purification by high-pressure liquid chromatography.
abstract: By Mannich condensation of o-Cresol Red, iminodiacetic acid and formaldehyde, Semi-Xylenol Orange (SXO) has been prepared in a 10-hr batch-procedure with a yield of about 30%. From the crude product SXO has been isolated by reversed-phase HPLC with perchloric acid-acetone mixtures as the mobile phase and C(18)-bonded silica as the stationary phase. The SXO fraction was freed from accompanying perchloric acid by a second separation on the same column, with water as eluent. After elution with acetone, the SXO was crystallized by evaporation.
authors.affiliation: Laboratory for Analytical Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, Amsterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Smedes
authors.forename: L G
authors.initials: LG
authors.lastname: Decnop-Weever
authors.forename: N T
authors.initials: NT
authors.lastname: Uyen
authors.forename: J
authors.initials: J
authors.lastname: Nieman
authors.forename: J
authors.initials: J
authors.lastname: Kragten