Comparison of the analytical methods for Cd in brown rice

현미중(玄米中) 카드뮴의 분석방법(分析方法)에 관(關)한 비교연구(比較硏究)

The wet ash method has been used as an official standard procedure for the analysis of Cd in brown rice in Korea, but this method involves several disadvantages. Thus, four analytical methods were compared in this experiment in order to find a more efficient method for the Cd analysis in brown rice. Evaluation was made based on both the Cd recovery percentages from the Cd-spiked samples and the relationships between Cd contents obtained by the official procedure and other methods. Results showed that ashing 50g brown rice at $600^{\circ}C$(dry ash method) recovered nearly 80% of the spiked Cd. This recovery percentage was a little lower than that of the wet ash method(87%) but higher than those of other methods. The dry ash method had the lowest standard deviations and revealed the highest correlation coefficient($r=0.98^{\ast\ast}$) in Cd contents with the standard wet ash method. These results demonstrated that the dry ash method, ashing 50g brown rice at $600^{\circ}C$, would be as efficient as the wet ash method and could be employed as a recommended procedure for the Cd analysis of brown rice.

현미중 카드뮴의 분석을 위한 보다 효율적인 방법을 찾기 위해 현미중 카드뮴의 공정시험방법을 표준으로 수종의 습식 및 건식방법에 대해 카드뮴의 회수율, 표준편차 및 표준방법과의 상관성등을 비교, 검토한 결과 현미 시료량 50g, 회화온도 $600^{\circ}C$의 건식방법은 회수율이 79.6%로 표준분석방법(87.2%)을 제외한 타 분석방법보다 높고, 표준편차도 평균${\pm}2.6$으로 표준분석방법의 평균+6.4 보다 약간 작았으며, 표준분석방법으로 분석된 카드뮴함량과의 상관성($r=0.977^{\ast\ast}$)도 크게 높아 본 방법은 습식으로 분해하는 현행 수질오염 공정시험 방법과 함께 현미중 카드뮴 분석방법으로 사용하여도 좋을 것으로 판단된다.