Fully Automated Determination of Trimellitic Anhydride in Saturated Polyester Resins Using Programmed Temperature Vaporization-Large Volume Injection-Gas Chromatography Previous Aqueous Derivatization with Triethyloxonium Tetrafluoroborate

Trimellitic anhydride (TMAn) is an essential starting material of the chemical manufacturing industry; it is widely used in saturated polyester resins (SPR) manufacturing to produce plasticizers for different purposes. TMAn was recently added, as a new substance of very high concern, to the candidate list by the European Chemicals Agency, since it can lead to sensitization, respiratory tract irritation and lung disease. Any substance from the list of candidates if present in manufactured products at concentrations above 0.1% (w/w) obliges the manufacturer to communicate this to customers down the supply chain and to consumers. We propose here a method that allows the fully automated determination of TMAn in SPR samples by using large volume injection (LVI), with programmed temperature vaporization (PTV) injection, in a gas chromatographic (GC) system equipped with ion trap mass spectrometer (IT) operating in tandem mass spectrometry (MS/MS). The method optimization was obtained by a chemometric model, using the experimental design. Introducing the use of short chromatographic column, triethyloxonium tetrafluoroborate (TEO) as derivatization agent and IS granted specificity, sensitivity and robustness. The detection and quantification limits for TMAn were 0.01% and 0.03% w/w, respectively. Trueness (between 94 and 98%) and precision (RSD lower than 10%, n = 6) were also assessed.