Using LC-QTof-MS to Identify HTPE Related Extractables and Leachables Compounds from Polymer Filter with Oligomer Hindered Amine Light Stabilizer (HALS)

Identification of Extractable and Leachables has been always challenging due to the lack of comprehensive library, massive degradants and derivatives, undefined chemical reaction mechanisms. Hindered amine light stabilizer (HALS), like Tinuvin 622, has been widely used in polymer products to protect plastic from degradation from long-term exposure to UV radiation. 4-Hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (HTPE) and related compounds were found in the extractable samples from plastic filter products stabled with HALS. An analytical assay has been developed and qualified to detect and measure the extractables and leachables compounds in the samples. Structures, molecular formulas and accurate masses of HTPE compounds were listed in this presentation, including HTPE, HTPE-BD, HTPE-BD-CH3, HTPE-BD-HTPE, HTPE-BD-C2H5 and others. It also includes additional compounds like HTPE-palmitic acid, HTPE-stearic acid, HTPE-BD-HTPE-Stearic acid, and various HTPE-BD combinations.
Here we introduce a quick approach to identify HTPE related compounds using Liquid Chromatography–Quadrupole Time-of-Flight Mass Spectrometry (LC–QTof-MS). First, a total ion chromatogram (TIC) of samples in both MS and elevated energy MS (MSE) mode are acquired. Next, characteristic fragment ions of HTPE related compounds, [C5H12NO]+ and [C9H15]+, were extracted to give extracted ion chromatograms (EICs). These peaks are quickly categorized and identified in the absence of libraries. This new approach greatly optimizes the accurate identification of polymer additive derivatives and enables a more precise E&L safety assessment.