Separation of ethoxylated bisphenol A dimethacrylates in dental composite after derivatisation to ionisable amines by capillary zone electrophoresis.
Bisphenol A ethoxylate dimethacrylates (Bis-EMA) are transformed into ionisable amines by derivatisation in order to make the analytes applicable to capillary electrophoresis. For this goal, piperidine was added onto the C=C double bond of the alpha,beta-unsaturated ester group forming a tertiary amine with pKa values between 9 and 10. Formation of the derivatives was confirmed by electrospray ionisation MS. Commercial Bis-EMA is a mixture of homologues with different number of ethoxy groups; it is characterised by the average number of the ethoxy groups in the chains. These homologues were resolved by capillary zone electrophoresis at pH 4. It is shown for the product with an average of four ethoxy groups per Bis-EMA molecule that about seven homologues can be baseline separated when differing by only one ethoxy group. For Bis-EMA with 30 ethoxy groups in average, about 23 homologues could be differentiated. The high resolution power of capillary zone electrophoresis enables characterisation of commercial dental composite material concerning the Bis-EMA constituents.
Musenga
Alessandro
A
Institute for Analytical Chemistry, University of Vienna, Währingerstrasse 38, A-1090 Vienna, Austria.
Schedle
Andreas
A
Demelbauer
Uwe
U
Kremser
Leopold
L
Raggi
Maria Augusta
MA
Kenndler
Ernst
E
D000588:Amines / Q000737:chemistry / Q000302:isolation & purification*; D001559:Benzhydryl Compounds; D003764:Dental Materials; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry / Q000302:isolation & purification*; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification*; D000098826:Bisphenol A Compounds
D000588:Amines; D001559:Benzhydryl Compounds; D003764:Dental Materials; D008689:Methacrylates; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds