Determination of Phthalate Esters by Positive Chemical Ionization MS with Retention-Time Locked GC

cern to Blount and co-workers (1) were the significantly higher concentrations of the dibutyl phthalate metabolite in the urine of childbearing-age women (20–40 years) than in that of other segments of the population. The presence of phthalate esters in polyvinyl chloride (PVC) toys has generated the most controversy. Regulators in Greece have completely banned soft PVC toys, and Austria, Denmark, Finland, France, Germany, Norway, and Sweden have banned phthalates in PVC toys for children less than three years old. In December 1999, the European Union (EU), concerned with a “serious and immediate risk” to children, placed an emergency ban on six of the phthalate esters in soft PVC toys and childcare products meant to be placed in the mouths of children less than three years old (2). None of the six banned phthalates can exceed 0.1% by weight. A recent study suggests a connection between high concentrations of phthalate esters in serum and the incidence of premature breast development in females less than eight years old in Puerto Rico (3). These heightened concerns suggest the need for an improved method of detecting and characterizing phthalate esters that can The authors describe a new instrumental method for the determination of phthalate esters using positive chemical ionization and retention-time locking gas chromatography. Positive chemical ionization with ammonia provides a high degree of selective ionization for the phthalates, primarily producing spectra in which the protonated molecule is the base peak. This method provides easy discrimination among the phthalates based upon their molecular weights, and retention-time locking enhances confidence in the identification of the various isomers. In their approach, the authors considered both pure compounds and technical mixtures. Determination of Phthalate Esters by Positive Chemical Ionization MS with Retention-Time Locked GC