A novel quantitation method for phthalates in air using a combined thermal desorption/gas chromatography/mass spectrometry application

- Phthalates are plasticizers added to improve the flexibility and durability of plastics.
- GC systems have been generally recommended for the quantitation of phthalates in air.
- The analysis of ambient phthalates is still difficult due to complicated analytical procedures.
- A new and efficient approach for ambient phthalate analysis is proposed by sorbent tube method.
- The applicability of the proposed method is validated by running actual environmental samples.

In this study, a novel quantitation method was developed to facilitate the simple and effective sampling and analysis of phthalates in air based on a sorbent tube-thermal desorption-gas chromatography-mass spectrometry system combination. The performance of the thermal desorption-based analysis was assessed using three different sorbent combinations [1]: quartz wool (QW) [2], glass wool (GW), and [3] quartz wool plus Tenax TA (QWTN) in terms of relative recovery in reference to a direct injection method. There was no significant difference in the average recovery rate for seven target phthalates based on sorbent tube type (QW, 70.2 ± 4.28; GW, 73.2 ± 8.8; and QWTN, 72.5 ± 5.02%). However, the recovery rate of phthalates in each sorbent tube type was distingusihed by physicochemical properties of the target compound (e.g., molecular weight and boiling point). The recovery rate of the QW tube was high for dimethyl phthalate and diethyl phthalate compared to other sorbent tubes, while that of the GW tube exhibited greater values for dibutyl phthalate, benzyl butyl phthalate, di(2-ethylhexyl) adipate, di(2-ethylhexyl) phthalate, and di-n-octyl phthalate. The simple sorbent tube-thermal desorption approach is feasible for the quantitation of seven phthalates present at 0.45-24.5 ng m−3 levels in actual air samples (20 L).

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