Determination of Cadmium in Tea-Camellia Seed Oil by Wet Digestion-Graphite Furnace Atomic Absorption Spectrometry

Although there is a clear definition for the threshold limit of lead(Pb) and arsenic(As) in vegetable oil which is 0.1 mg/kg in GB2716-2005,no threshold limit for cadmium was given in this standard.In this study,tea-camellia seed oil which is popularly studied was chosen and investigated.A new method using wet digestion-graphite furnace atomic absorption spectrometry was established in which HNO3 and H2O2 is used as the acidic system.The content of cadmium in the crude and refined tea-camellia seed oil were determined by the method.The results matched with those for other plant oils reported previously.The detection limit,RSD and recovery rate of this method is 0.058 μg/L,12%,and in the range of 84%~103%,respectively.Thus it concluded that this method is reliable and has high sensitivity.