Rapid and nondestructive analysis of phthalic acid esters in toys made of poly(vinyl chloride) by direct analysis in real time single‐quadrupole mass spectrometry

Abstract

In the European Community, selected phthalic acid esters (PAE) are restricted in their use for the manufacture of toys and childcare articles to a content of 0.1% by weight. As PAE are mainly used as plasticisers for poly(vinyl chloride) (PVC), a rapid screening method for PVC samples with direct analysis in real time ionisation and single-quadrupole mass spectrometry (DART-MS) was developed. Using the ions for the protonated molecules, a limit of detection (LOD) of 0.05% was obtained for benzyl butyl phthalate, bis(2-ethylhexyl) phthalate and diisononyl phthalate, while for dibutyl phthalate, di-n-octyl phthalate and diisodecyl phthalate the LOD was 0.1%. Validation of identification by the presence of ammonium adducts and characteristic fragment ions was possible to a content of >or=1% for all PAE, except for benzyl butyl phthalate (>or=5%). Based on the fragment ions, bis(2-ethylhexyl) phthalate could clearly be distinguished from di-n-octyl phthalate, if the concentrations were >r=5% and >or=1% at measured DART helium temperatures of 130 and 310 degrees C, respectively. The complete analysis of one sample only took about 8 min. At the generally used gas temperature of 130 degrees C, most toy and childcare samples did not sustain damage if their shape fitted into the DART source.