Abstract:

Leather is one of the important exporting products to European Union (EU), and tris(2-chloroethyl)phosphate (TCEP) is a commonly used flame retardant in leather and leather products. Recently, TCEP has been classified as a kind of substance of very high concern (SVHC) by EU for its carcinogenicity and reproductive toxicity. But to date, there is not a recognized method for the determination of TCEP in leather and leather products due to the serious matrix interferences and relatively low recovery of TCEP. In this work, a home-made mixed-mode sorbent (Silica-WCX) with carboxyl and alkyl groups was tested as the sorbent of solid phase extraction (SPE) to extract TECP from leather. The results demonstrated that, making the carboxyl groups protonized under acidic condition, Silica-WCX exhibited better extraction performance towards TCEP over some frequently used commercial sorbents tested. After the optimization of the SPE conditions based on Silica-WCX, a method of gas chromatography/mass spectrometry (GC-MS) was established for the determination of TCEP in leather samples. The linear range for TCEP ranged from 0.10 to 100.0 μg/L and the limit of quantification (LOQ, S/N=10) was 44.46 ng/kg. The recoveries of TCEP spiked in samples at varied levels were in the range of 91.45%-99.98% with the relative standard deviations (RSDs) of 4.33%-5.97%. The method is simple, sensitive and reliable for the analysis of TCEP in leather and leather products.

Key words: gas chromatography-mass spectrometry (GC-MS), leather, mixed-mode sorbent, solid phase extraction (SPE), tris(2-chloroethyl)phosphate (TCEP)