We tried to reduce the styrene (ST) carryover on the chromatogram in the official testing method for the food utensil, container, and packaging products made of polystyrene. The carryover was not reduced by changing the GC oven temperature program, analyzing some wash solutions, and washing the injection syringe. With the use of the new syringe, it was slightly reduced. It was completely removed by replacing the quartz or glass wool in the liner with a new one, suggesting that the cause of ST carryover might be due to the oligomer or polymer accumulated in an inlet liner. The estimated ST amount of the carryover was not higher than one-tenth of the standard value, showing that the suitability determination would not be affected by them. However, for an accurate determination, to confirm the carryover before the determination would be needed.
