| 利用in vitro方法研究不同铁矿对土壤砷生物可给性的影响 |
| 摘要点击 2529 全文点击 928 投稿时间：2016-08-16 修订日期：2016-09-24 |
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| 中文关键词 生物可给性 in vitro 铁矿物 砷 稳定化 |
| 英文关键词 bioaccessibility in vitro iron mineral arsenic stabilization |
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| 中文摘要 |
| 为了研究不同铁矿物对土壤砷生物可给性的影响，利用PBET（physiologically based extraction test）、SBRC（solubility bioaccessibility research consortium assay）和IVG（in vitro gastrointestinal extraction）这3种in vitro方法研究水铁矿、针铁矿和赤铁矿对土壤砷在胃与小肠阶段生物可给性的影响以及砷形态转化对砷的生物可给性影响机制.结果表明，添加1%水铁矿时，根据PBET、SBRC和IVG这3种in vitro方法，胃阶段砷的生物可给性分别为2.22%、5.11%和7.43%，小肠阶段砷的生物可给性分别为3.39%、2.33%和6.18%；当投加量提高到2%时，各阶段砷的生物可给性都显著降低（P<0.05）.3种in vitro方法，在不同铁矿物投加量相同条件下，相比于空白对照组（CK），砷的生物可给性降低幅度大小依次为：水铁矿（F1）> 针铁矿（G1）> 赤铁矿（H1）（F2 > G2 > H2）.3种in vitro方法中可交换态和专属吸附态砷总量（F1+F2）同胃阶段砷的生物可给性呈正相关性，依据PBET、SBRC和IVG法，相关系数分别为r=0.93，P=0.002、r=0.90，P=0.004和r=0.89，P=0.006；F1+F2同小肠阶段砷的生物可给性呈正相关性，PBET和IVG法的相关系数分别为r=0.94，P=0.001和r=0.87，P=0.009，而SBRC法则表现为没有相关性.同样，3种in vitro方法中都表现出无定型铁结合态砷（F3）与胃阶段砷的生物可给性有显著负相关性，而与小肠阶段砷生物可给性则除了SBRC法没有相关性之外，PBET和IVG法都表现出显著负相关性. |
| 英文摘要 |
| To explore the effects of different iron minerals on soil arsenic bioaccessibility, ferrihydrite, goethite and hematite were used in PBET, SBRC and IVG in-vitro experiments in this study. The relationship between arsenic bioavailability in gastric, small intestinal phases and arsenic speciation was also studied. The results showed that when 1% ferrihydrite was added, arsenic bioavailability in gastric phase was 2.22%, 5.11% and 7.43% by PBET, SBRC and IVG methods, respectively, while in the small intestinal phase it was 3.39%, 2.33% and 6.18%. At an elevated ferrihydrite dosage of 2%, significant difference in arsenic bioavailability was observed in both phases (P<0.05). According to in vitro experiments, the addition of the same amount of different iron minerals had contributed to the decrease in arsenic bioavailability to varying extents in contrast with the blank group, in the descending order of ferrihydrite(F1) > goethite(G1) > hematite(H1) (F2 > G2 > H2). Total arsenic in exchangeable (F1) and specifically sorbed (F2) state was found positively correlated with arsenic bioavailability in gastric phase by PBET, SBRC and IVG methods, the correlation coefficient of which being r=0.93, P=0.002, r=0.90, P=0.004 and r=0.89,P=0.006, respectively. It was also found that arsenic bioavailability in gastric phase was positively correlated with total arsenic in F1 and F2 states by PBET(r=0.94,P=0.001) and IVG (r=0.87,P=0.009) methods, but no significant correlation was observed by SBRC method. Additionally, three in vitro experiments showed that amorphous iron bound arsenic had significant negative correlation with arsenic bioavailability in gastric phase and small intestinal phase, except that no correlation was found in small intestinal phase by SBRC method. |
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