Optimization of Hydrophilic-Lipophilic Balance Solid-Phase Extraction of Phthalates in Pharmaceutical Preparations

Abstract

Phthalates, which are used as plasticizers to soften rough polymers in the industrial processes,possess endocrine system disrupting activities. In this study, a hydrophilic-lipophilic balance solid-phaseextraction method was optimized for seven phthalates as dimethyl, dipropyl, benzyl butyl, di-n-butyl,dicyclohexyl, di-(2-ethylhexyl) and di-n-octyl phthalates in terms of the type and the volume of theconditioning and the elution solvents. The phthalates were quantified by a validated HPLC/UV method. Therecovery values were higher than 80% for dimethyl, dipropyl, benzylbutyl, di-n-butyl and dicyclohexylphthalates. Using optimized conditions, three types of liquid pharmaceutical preparations as an intravenousisotonic sodium chloride solution, an intravenous dextrose solution and an osmotic laxative kept inpolymeric packages were analyzed with high accuracy, precision and recovery. Only the intravenousisotonic sodium chloride solution was determined to be contaminated with dipropyl phthalate at aconcentration of 13.2±0.16 μg/L.