Optimization study of GC-MS and IDMS technique for separation of benzophenone and its derivatives from food packaging paper

Abstract

This report is a study of optimized condition for GC-MS and Isotope Dilution Mass spectrometry (IDMS) techniques to separate mixture of benzophenone and its derivatives; involving 4-methylbenzophenone, 4-hydroxybenzophenone, 2-hydroxybenzophenone, 4,4'-bis (dimethylamino) benzophenone and 4,4'-bis (diethylamino) benzophenone. These 6 carcinogenic compounds are photo-initiators; used in UV cure ink for food packaging paper. In this study, benzophenone-D10 was used as an internal standard and 50% diphenyl/50% dimethyl polysiloxane capillary column was selected as a GC-MS column. This study was performed through varying of GC oven temperature; including initial, final and increasing temperature rate under the GC-MS full scan mode. The results show 3 studied methods could obtain all 6 dangerous compounds separately in 24, 29 and 41 min, respectively. The optimized GC oven temperature was selected from the method using the shortest runtime (24 min) and the GC-MS full scan mode has been changed to a selective ion monitoring (SIM) mode instead to achieve the differences between quantified peak of benzophenone (m/z = 105) and of benzophenone-D10 (m/z= 110). Finally, the optimized condition of the GC-MS technique from this study can be used to analyze benzophenone and its 5 derivatives in food packaging paper sample by comparison to standard calibration curve that the correlation coefficient was in the limit of acceptance ( R²0.990)