School of Nuclear and Allied Sciences, University of Ghana, Legon, Ghana.
Environ Monit Assess. 2013 Oct;185(10):7979-91. doi: 10.1007/s10661-013-3148-9. Epub 2013 Mar 15.
Total As content and the As species distribution in water and sediments from the Kwabrafo stream, a major water body draining the Obuasi gold mining community in southwestern Ghana, have been investigated. Total As content was determined by instrumental neutron activation analysis (INAA). Ion-pair reverse phase high-performance liquid chromatography-neutron activation analysis (HPLC-NAA) was used for speciation of As species. Solid phase extraction with phosphate buffer was used to extract soluble As species from lyophilized sediment. The mass balance after phosphate extraction of soluble As species in sediment varied from 89 to 96 %. Compositionally appropriate reference material International Atomic Energy Agency (IAEA)-Lake Sediment (SL)-1 was used to check the validity of INAA method for total As determination. The measured values are in good agreement with the IAEA recommended value and also within the 95 % confidence interval. The accuracy of the measurement in terms of relative deviation from the IAEA recommended value was ±0.83 %. "In-house" prepared As(III) and As(V) standards were used to validate the HPLC-INAA method used for the As species determination. Total As concentration in the water samples ranged from 1.15 to 9.20 mg/L. As(III) species in water varied from 0.13 to 0.7 mg/L, while As(V) species varied from 0.79 to 3.85 mg/L. Total As content in sediment ranged from 2,134 to 3,596 mg/kg dry mass. The levels of As(III) and As(V) species in the sediment ranges from 138 to 506 mg/kg dry mass and 156 to 385 mg/kg dry mass, respectively.
已对源自加纳西南部 Obuasi 金矿社区主要排水体 Kwabrafo 溪的水和沉积物中的总砷含量和砷形态分布进行了研究。采用仪器中子活化分析（INAA）测定总砷含量，离子对反相高效液相色谱-中子活化分析（HPLC-NAA）用于砷形态的形态分析。采用磷酸盐缓冲液固相萃取法从冻干沉积物中提取可溶态砷。磷提取后沉积物中可溶态砷的质量平衡在 89%至 96%之间变化。使用成分合适的参考物质国际原子能机构（IAEA）-湖泊沉积物（SL）-1 来检查 INAA 法测定总砷的有效性。测量值与 IAEA 推荐值吻合良好，也在 95%置信区间内。从 IAEA 推荐值的相对偏差来看，测量的准确度在±0.83%范围内。“内部”制备的 As(III)和 As(V)标准品用于验证用于砷形态测定的 HPLC-INAA 方法。水样中的总砷浓度范围为 1.15 至 9.20mg/L。水中的 As(III)形态从 0.13 至 0.7mg/L 不等，而 As(V)形态从 0.79 至 3.85mg/L 不等。沉积物中的总砷含量范围为 2134 至 3596mg/kg 干重。沉积物中 As(III)和 As(V)形态的含量范围分别为 138 至 506mg/kg 干重和 156 至 385mg/kg 干重。
