Hamano-Nagaoka Megumi, Nishimura Tsutomu, Matsuda Rieko, Maitani Tamio
National Institute of Health Sciences, Tokyo, Japan.
Shokuhin Eiseigaku Zasshi. 2008 Apr;49(2):95-9. doi: 10.3358/shokueishi.49.95.
Arsenic (As) uptake in human occurs via the food chain mainly. The Joint FAO/WHO Expert Committee on Food Additives has established the provisional tolerable weekly intake level for As as an inorganic As (iAs) value, because iAs in food is much more toxic than organic As. In this study, we studied an acid based partial-digestion method for the complete extraction of arsenicals from rice. HPLC/ICP-MS was used to determine the concentration of iAs selectively. The conditions adopted to extract arsenicals from a 0.5 g of finely ground rice sample were addition of 2 mL of 0.15 mol/L nitric acid and heating at 80 degrees C for 2 hr. The LOD and LOQ for iAs were 0.0024 and 0.0079 mg/kg dry weight, respectively. Recovery studies showed good accuracy. When the method was applied to ten short-grain brown rice samples, the iAs concentrations were 0.108-0.227 mg/kg dry weight and the total As concentrations were 0.118-0.260 mg/kg dry weight. Although dimethylarsinic acid was also detected in most samples, the percentage of iAs content in total As content was 62.2-96.3%. Thus, iAs was the principal As species in the short-grain brown rice samples tested.
人体摄入砷（As）主要通过食物链。联合国粮食及农业组织/世界卫生组织食品添加剂联合专家委员会已确定砷的暂定每周耐受摄入量水平为无机砷（iAs）值，因为食品中的iAs毒性远高于有机砷。在本研究中，我们研究了一种基于酸的部分消化方法，用于从大米中完全提取砷化物。采用高效液相色谱/电感耦合等离子体质谱法（HPLC/ICP-MS）选择性地测定iAs的浓度。从0.5 g精细研磨的大米样品中提取砷化物所采用的条件为加入2 mL 0.15 mol/L硝酸并在80℃加热2小时。iAs的检测限（LOD）和定量限（LOQ）分别为0.0024和0.0079 mg/kg干重。回收率研究显示出良好的准确性。当该方法应用于10个短粒糙米样品时，iAs浓度为0.108 - 0.227 mg/kg干重，总砷浓度为0.118 - 0.260 mg/kg干重。尽管在大多数样品中也检测到了二甲基砷酸，但iAs含量占总砷含量的百分比为62.2 - 96.3%。因此，iAs是所测试的短粒糙米样品中的主要砷形态。
