Rapid Analysis of Trace Phthalates by Spray-Inlet Microwave Plasma Torch Ionization Tandem Mass Spectrometry in...

The less volatile fraction of perfumes is susceptible to contamination by phthalate esters (PAEs), which are endocrine-disrupting chemicals encountered during the production, bottling, and transportation processes. There is a need to establish an innovative and rapid method for the determination of trace PAEs in commercial perfumes.

Therefore, self-built spray-inlet microwave plasma torch (MPT) ionization coupled with quadrupole time-of-flight (QTOF) tandem MS (MS/MS) was developed for the direct analysis of PAEs in perfumes without sample pretreatment.

Perfumes were sprayed directly onto the flame of the MPT by means of a sampling pump at a rate of 10 µL/min and the ions produced by the MPT were introduced into the QTOF-MS equipment with the MPT operating at 2450 MHz and 40 W at a flow rate of 800 ml/min of argon.

For the established method, excellent linearity was obtained with a correlation coefficient of 0.9799 for di-n-pentyl phthalate and of greater than 0.99 for the other substances tested. The LOD and LOQ obtained were in the ranges of 1.452-18.96 and 4.839-63.19 ng/g, respectively. The spiked recoveries of PAEs ranged from 100.1 to 105.2% with satisfactory intraday RSDs and interday RSDs ranging from 1.51 to 4.34% and 3.45 to 5.65%, respectively. PAEs in commercial perfumes were successfully detected by spray-inlet MPT-MS/MS with low concentrations ranging from 0.036 to 1.352 µg/g.

The method is a promising tool for the on-site analysis of PAEs in cosmetic solutions requiring rapid qualitative and quantitative analysis.

The method was successfully applied to the analysis of the commercial perfume samples within 30 s, and displayed the merits of simplicity, sensitivity, environmental friendliness and ease of operation.