Characterization of gamma-irradiated polyethylene terephthalate by liquid-chromatography–mass-spectrometry (LC–MS) with atmospheric-pressure chemical ionization (APCI)

A Comparative Mass‐Spectrometric Study of Plasma‐ and Vacuum Ultraviolet Ablation of Selected Polymers

“…Skurat and Dorofeev30 have underlined that for hν > 10 eV the photo‐ionisation of polymer molecules becomes possible, and that photolysis by the present Ly α radiation and γ radiolysis should be similar to some extent. It is therefore interesting to attempt to compare the main radiolysis products reported by Buchalla et al43–46 with products observed here. Those authors used thermal desorption–gas chromatography–MS (TD‐GC‐MS) to analyse volatile radiolysis products in all five polymers investigated here (among others we have not studied), in all cases after 25 kGy doses of 60 Co γ irradiation.…”

“…Unlike volatile species resulting from exposing polymers to plasma or VUV (which originate at the very surface or from a tens of nm‐thin near‐surface region, respectively), the γ radiolysis products tended to be retained in the bulk of the polymer films for extended periods of time. That is why analysis of the gas products by Buchalla et al43–46 was done only after TD of all volatile products from the irradiated samples. In our case, of course, gaseous products were analysed by MS in situ.…”

“…Several authors have used MS to study γ radiolytic43–46 or photolytic degradation reactions of commercial polymers, and to identify the volatile products evolving from those solids; in several studies, MS was used to investigate in situ e‐beam, γ radiation, plasma and VUV interactions with various polymers 30, 33, 47–52. In those articles numerous gaseous products were identified, but no systematic quantitative investigations were attempted in order to understand the peculiarities of ablation reactions under plasma and VUV exposures.…”

“…In those articles numerous gaseous products were identified, but no systematic quantitative investigations were attempted in order to understand the peculiarities of ablation reactions under plasma and VUV exposures. Regarding radiolysis, more than 100 volatile products were detected during γ irradiation of hydrocarbon polymers like PE and PP, but only half of them were identified 43–46…”

Contamination from Sterilization Procedures

“…Buchalla and Begley [69], using an lC-MS system, analyzed gammairradiated (25 and 50 kGy) PET samples and also found that this is a very radiation-resistant polymer. The concentration of the major compounds that were present in the acetone extract of nonirradiated samples did not change perceptibly in the extracts of irradiated samples.…”