抄録
To improve the peak shape of caprolactam (CPL) on the chromatogram in the official testing method for the food utensil,
container, and packaging products made of nylon, we tried to find the cause and modified the GC analytical conditions. The cause
of deterioration of CPL peak shape was seemed to be due to the overload of test solution into the GC glass liner. We changed the
GC analytical conditions, such as column size, injection volume of test solution, split ratio, inlet temperature, GC oven temperature
condition, liner type, and glass wool volume in a liner, and diluted test solution by ethanol or acetone. The peak shape of CPL
was considerably improved when the inlet temperature was set to 280ºC at the highest column heat resistant temperature, in
addition, the injection volume was changed to half or the test solution was diluted by ethanol or acetone. Furthermore, the peak
shape of heptalactam (HPL) that was added to the test solution as an internal standard showed the same peak shape as CPL on the
chromatogram. This result suggested that HPL was thought to be available not only for the original purpose, such as correction of
sample injection, but also for the confirmation of peak separation of CPL.
