Determination of Phthalates and Adipate in Physiological Saline Solutions by Solid-Phase Microextraction and Gas Chromatography

Abstract

This study describes an analytical methodology developed for determination of phthalate esters (di-n-butyl, butylbenzyl and di-2-ethylhexyl phthalate) and adipate (di-n-ethylhexyl adipate) by solid-phase microextraction (SPME) and gas chromatography in normal saline solutions and, in bi-distilled water used to reconstitute medicines. An 85-μm-polyacrylate SPME fiber was selected and used in all analyses. The parameters affecting extraction efficiency were simultaneously optimized, firstly by means of a two-level full factorial design including a center point and subsequently through a Doehlert design for two-variables. Satisfactory detection limits in the range of 0.18 to 0.75 μg L⁻¹ and excellent precision, with relative standard deviation values being lower than 15.1% (n = 6), were obtained. Relative sensitivities of between 72.3 and 124.3% were obtained.