畜禽养殖场土壤中砷的测定-以水作载流的氢化物发生原子荧光光谱法

为监测畜禽养殖场对周围土壤环境的污染程度,选择重庆市50个养殖场作为样本,对其附近的土壤进行采样分析。将新鲜的土壤样品加入适量的硝酸、盐酸、氢氟酸、高氯酸高温消解后赶酸,最后定容至50 mL,利用以水作载流的氢化物发生-原子荧光光谱仪(WC-HG-AFS)测定了其中的砷(As)含量。结果表明,在5.000~100.000 mg/kg范围内线性相关系数R²=0.99997,检出限为0.074 mg/kg,样品的相对标准偏差(RSD)为1.6%,5份平行样品分析结果的相对偏差分别为6.86%、7.68%、1.12%、13.10%、11.25%,均小于实验室分析质量控制标准相对偏差允许限25.84%,三种标准物质分析结果的标准推荐值的相对误差为2.3%、1.9%、3.1%,均小于其对应的相对误差允许限14.1%、9.8%、12.4%,数据可靠。检测结果表明,除一个检测点外(011属于Ⅱ类土壤),其他养殖区土壤中的总As含量低于《土壤环境质量标准》(GB 15618—1995)中规定的一级标准中As的最高限值15 mg/kg,属于Ⅰ类土壤,目前环境质量较好,畜禽养殖并未对当地环境造成明显危害。

Determination of Arsenic in the Soil of Livestock and Poultry Farms by Water Carrier- Hydride Generation -Atomic Fluorescence Spectrophotometry

In order to monitor the pollution degree of livestock and poultry farms to the surrounding soil environment, 50 livestock farms in Chongqing were selected as samples to analyze the soil around them. Add appropriate amount of nitric acid, hydrochloric acid, hydrofluoric acid, and perchloric acid to the fresh soil sample. They are digested at high temperature, and then the acid is removed, and the volume is adjusted to 50 mL. Finally, the arsenic (As) content was measured by hydride generation-atomic fluorescence spectrophotometer (WC-HG-AFS) with water as carrier. The results of atomic fluorescence spectrophotometry are as follows: within the concentration range of 5.000 mg·kg-1~100.000 mg·kg-1, the linear correlation coefficient R2=0.99997; the detection limit is 0.0742 mg·kg-1, the relative standard deviation of the sample (RSD) ) is 1.585%. The relative deviations of the analysis results of 5 parallel samples are 6.86%, 7.68%, 1.12%, 13.10%, 11.25%, which are all less than the allowable relative deviation of 25.84%. The relative errors of the standard recommended values are 2.3%, 1.9%, and 2.7%, which are all smaller than their corresponding relative tolerance limits of 14.1%, 9.8%, and 21.3%. Except for the 011 monitoring point, the As content in the soil of other breeding areas is even lower than the highest limit of As in the first-level standard specified in the Soil Environmental Quality Standard (GB 15618-1995), which is 15 mg·kg-1.