Fast screening of prohibited chemicals in plastic toys using ambient ionization mass spectrometry

Abstract

In this work, we developed methods for rapid analysis of prohibited chemicals in trade products, e.g. plastic toys for children. Two ambient ionization methods, zero-voltage paper spray ionization (zvPSI) and transmission low-temperature plasma (T-LTP) probe, were used to enable the direct detection of a broad range of prohibited substances, including plasticizers, disperse dyestuffs, and aromatic amines. The limits of detection (LODs) achieved for plasticizers and disperse dyestuffs/aromatic amines were 0.080–3.9 ng and 0.024–0.77 ng, respectively. Extremely simple sampling process was involved by surface chemical extraction using organic solvents. The developed methods were applied for detecting prohibited harmful chemicals in 12 plastic toy samples, among which four were detected with di(2-ethyl)hexyl phthalate, a commonly used plasticizer. The total time of the entire analysis process for each sample was less than 3 min, from sampling to final mass spectrometry (MS) analysis, making the methodology suitable for real-time analysis. The developed method could potentially be implemented for rapid pre-screening of trade products at the customs, especially when coupled with a miniature mass spectrometer.