化学提取方法快速评估污染土壤中生物可消化性铅

为建立一种简单的方法鉴定污染土壤中的铅在消化系统中被人体消化吸收的潜力（即生物可消化性或生物可接受性），采用连续提取法和7种单一化学提取法比较研究了13个污染土壤中铅的化学形态及其可提取性，以模拟胃液提取法为参比，选择和比较了7种化学提取剂，包括：CaCl2稀盐、NH4OAc、DTPA—TEA、Mehlich Ⅰ、Mehlich Ⅲ、草酸铵缓冲液和盐酸羟铵溶液。结果表明，土壤中铅的平均提取率由高至低依次为：草酸铵缓冲液，盐酸羟铵溶液，MehlichⅠ、MehlichⅢ，DTPA—TEA，NH4OAc，CaCl2相关分析表明，氧化物结合态铅是污染土壤中生物可消化铅的主要组分，用盐酸羟铵溶液提取的铅可很好地表征污染土壤中铅的生物可消化性，其提取量与模拟胃液提取的铅接近，两者之间具有显著的相关性。

Chemical Extraction Methods to Assess Digestive Lead in Contaminated Soils

Lead extracted by seven commonly used soil extractants was compared with bioavailable Pb measured by simulated gastric and intestinal solution. Thirteen contaminated soils that contained 81 to 710 mg/kg Pb were tested. Selected soil extractants were CaCl2, NH4OAc, DTPA - TEA, Mehlich I , Mehlich m, ammonium oxalate and hydroxylamine hydrochoride. Amorphous oxides-bound Pb can be designed to provide closer estimates of bioavailable Pb. Extractable Pb using hydroxylamine hydrochoride were significantly correlated with bioavailable Pb measured by simulated gastric and intestinal solution, and could better predict oral bioaecessibility of Pb in contaminated soils.