Determination of particulate and gaseous phthalic acid esters in ambient air by large-volume injection-gas chromatography-mass spectrometry.

A sensitive and effective analytical method has been optimized and validated for the determination of particulate and gaseous phthalic acid esters (PAEs) in ambient air. The samples were Soxhlet extracted with an n-hexane-dichloromethane-methanol mixture (1:1:1, volume ratio), and analyzed using large-volume injection coupled to a gas chromatography-mass spectrometry (LVI-GC-MS) system. Standard sample linearity in the range of 0.02 approximately 5 microg L(-1) provides regression coefficients (R(2)) better than 0.995. Limits of detection (LODs) and limits of quantification (LOQs) were at the microg L(-1) level. Because the air sample volumes were 360 m(3), the accuracy and precision for the PAE concentrations at the pg m(-3) level were guaranteed. This sensitivity is much higher than the conventional 2 microL splitless injection and is suitable for the detection of ultra-trace PAEs in complex air matrices.