Premium
Direct detection of additives and degradation products from polymers by liquid extraction surface analysis employing chip‐based nanospray mass spectrometry
Author(s) -
Paine Martin R. L.,
Barker Philip J.,
Maclauglin Shane A.,
Mitchell Todd W.,
Blanksby Stephen J.
Publication year - 2012
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6116
Subject(s) - melamine , chemistry , polymer , coating , degradation (telecommunications) , mass spectrometry , extraction (chemistry) , chemical engineering , polymer degradation , chromatography , organic chemistry , telecommunications , computer science , engineering
RATIONALE Polymer‐based surface coatings in outdoor applications experience accelerated degradation due to exposure to solar radiation, oxygen and atmospheric pollutants. These deleterious agents cause undesirable changes to the aesthetic and mechanical properties of the polymer, reducing its lifetime. The use of antioxidants such as hindered amine light stabilisers (HALS) retards these degradative processes; however, mechanisms for HALS action and polymer degradation are poorly understood. METHODS Detection of the HALS TINUVIN®123 (bis(1‐octyloxy‐2,2,6,6‐tetramethyl‐4‐piperidyl) sebacate) and the polymer degradation products directly from a polyester‐based coil coating was achieved by liquid extraction surface analysis (LESA) coupled to a triple quadrupole QTRAP® 5500 mass spectrometer. The detection of TINUVIN®123 and melamine was confirmed by the characteristic fragmentation pattern observed in LESA‐MS/MS spectra that was identical to that reported for authentic samples. RESULTS Analysis of an unstabilised coil coating by LESA‐MS after exposure to 4 years of outdoor field testing revealed the presence of melamine (1,3,5‐triazine‐2,4,6‐triamine) as a polymer degradation product at elevated levels. Changes to the physical appearance of the coil coating, including powder‐like deposits on the coating's surface, were observed to coincide with melamine deposits and are indicative of the phenomenon known as polymer 'blooming'. CONCLUSIONS For the first time, in situ detection of analytes from a thermoset polymer coating was accomplished without any sample preparation, providing advantages over traditional extraction‐analysis approaches and some contemporary ambient MS methods. Detection of HALS and polymer degradation products such as melamine provides insight into the mechanisms by which degradation occurs and suggests LESA‐MS is a powerful new tool for polymer analysis. Copyright © 2012 John Wiley & Sons, Ltd.