Consideration on the Detection Method of Irradiated Chicken by GC/FID Analysis of 2-alkylcyclobutanones and hydrocarbons

Abstract

Radiation induced 2-alkylcyclobutanones (RCB) and hydrocarbons (HC) were analyzed for the detection of irradiated chicken using GC/FID analysis of simultaneous soxhletflorisil chromatography.
In this study, 1.5μg/g ⋅fat of n pentadecane (C_{15: 0}), 1.9μg/g⋅fat of 1-tetradecene (C_{1-14: 1}), 0.71μg/g⋅fat of n-heptadecane (C_{17: 0}), 0.60μg/g ⋅fat of 1-hexadecene (C_{1-16: 1}), 3.0μg/g⋅fat of 8-heptadecene (C_{8-17: 1}) and 4.3μg/g⋅fat of 1, 7-hexacadiene (C_{1, 7-16: 2}) were detected from chicken irradiated at 2.7 kGy by GC/FID. At the same time, 0.53μg/g⋅fat of 2-dodecylcyclobutanone (DCB), 0.17μg/g⋅fat of 2-tetradecylcyclobutanone, 0.14μg/g⋅fat of 2-dodec-5'-enylcyclobutanone and 1.4μg/g⋅fat of 2-tetradec-5'-enylcyclobutanone (TeCB) were detected from same sample of chicken. The amount of these radiolytic products from irradiated chicken, 6HC and 4RCB, increased depending on dose increment from 0.5 kGy to 10 kGy.
HC of C_{1, 7-16: 2}, C_{8-17: 1} and TeCB were produced 9.6 nmol/kGy per 1g fat in all from oleic acid And from palmitic acid C_{15: 0}, C_{1-14: 1} and DCB were produced 5.2 nmol/kGy/g⋅fat in all.
1) Analyzing procedure of main fatty acids is complicated 2) Measurement of amount of blank of saturated HC from food sample is difficult. 3) Radiolytic products from stearic acid in chicken is low density. 4) Parent fatty acid in triglyceraide is not always same and fat in food is composed of many kind of triglyceraide. Therefore C_{n-2: 1}/C_n-1 is not always constant. From these four reasons, it is concluded that using ratio of C_{n-2: 1} and C_n-1 for detection of irradiated food is doubtful.
This study further shows detection of irradiated food is capable exactly using both radiation induced HC of C_{1, 7-16: 2}, C_{8-17: 1} and C_{1-14: 1}, and RCB of DCB and TeCB from main fatty acid in the food.