Page 14 - Shimadzu Journal vol.2 Issue3

Polymer

Analysis of Minor Components in Synthetic

Polymers Using SEC-AccuSpot-AXIMA System

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

Table 1 Analytical Conditions
• SEC Column : Shodex GF310A-1E (1.0 mmI.D.× 250 mm)
Flow Rate : 10 L/min, Eluent : THF
μ
μ
Detector :UV (λ=220 nm), Injection volume : 1 L
• AccuSpot Spot Interval : 6 sec, Loadage : 1 L/well
μ
Loadage (mixture of
poly(MMA-b-n-BMA)
Fraction start Fraction end matrix and cationizing
8 min 20 sec 13 min 20
μ
reagent) : 0.2 L/well
• MALDI-TOFMS Matrix : Dithranol-20 mg/mL- THF
Cationizing Reagent : Na-TFA-10 mg/mL -THF
THF : Tetrahydrofuran, TFA : Trifluoroacetic acid
Fig. 1 SEC Chromatogram of Poly (MMA-b-n-BMA)

Pre-separation

After 9 min 48 sec
After 10 min 18 sec

After 10 min 42 sec
After 10 min 54 sec

After 11 min 06 sec
After 11 min 18 sec

After 11 min 30 sec
After 11 min 42 sec

After 11 min 54 sec
1000 2000 3000 4000 5000 6000
m/z
Fig. 2 MS Spectra of SEC-Separated Fractions

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