Analysis of Minor Components in Synthetic Polymers Using SEC-AccuSpot-AXIMA System (1)

Introduction

MALDI-TOF mass spectrometry is widely used as a technique for the characterization of synthetic polymers. However, when multiple components are present in samples, major components may suppress ionization of the trace components present, preventing their detection. Size exclusion chromatography, (SEC) is a chromatographic method that can be used to prevent this adverse result by separating the components into fractions beforehand. However, off-line SEC/MALDI MS involves fraction collection, evaporation, pipetting, etc. and is laborious and time consuming, so direct deposition methods in which SEC fractions and MALDI matrix are directly deposited onto the MALDI target are preferred. Shimadzu has developed the AccuSpot automated spotter to mix the eluate from the LC with the various reagents and directly load them onto the MALDI sample plate. As a result, an automated analytical SEC-MALDI analysis system was constructed that can rapidly simplify all the processing from LC separation to MALDI-TOFMS measurement. Here, using a copolymer - poly (methylmethacrylate- b-n-butylmethacrylate) (poly (MMA-b-n-BMA)) -a sample with a complicated composition, we present an example of detection of a homopolymer present at trace levels in the sample. The size exclusion chromatography (SEC) mode was used for the separation, and a micro-scale separation column was used to load all of the components onto the MALDI sample plate without any waste. The AccuSpot body is constructed with enhanced resistance to many organic solvents used in the field of synthetic polymers.

February 6, 2009 GMT