纳米钛酸锶钡粉体吸附富集-火焰原子吸收光谱法测定水样中锰离子
FAAS Determination of Manganese Ion in Water with Enrichment by Adsorption on Nano Barium Strontium Titanate Powder
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摘要: 提出了纳米钛酸锶钡粉体吸附富集,火焰原子吸收光谱法测定水中痕量锰的含量.在pH 6的氨性缓冲介质中,采用纳米钛酸锶钡(0.02 g)对水样(10 mL)中的锰离子振荡吸附15 min.优化条件下吸附容量达5.4 mg·g-1.方法检出限(3s/k)为2.1 μg·L-1.用0.15 mg·L-1锰(Ⅱ)标准溶液连续测定6次,求得其相对标准偏差(n=6)为3.4%.用于河水和地下水中痕量锰的测定,用标准加入法测得方法的回收率在93.5%~99.7%之间.Abstract: Traces of Mn(Ⅱ) in water were enriched by adsorption with shaking for 15 min on nano-barium strontium titanate powder (0.02 g) in 10 mL of solution of pH 6 buffered with ammoniacal buffer solution.The adsorption capacity of Mn(Ⅱ) under the optimum conditions mentioned above attained to a value of 5.4 mg·g-1.Manganese ion was then desorbed from the nano powder by shaking with 5 mL of 0.17 mol·L-1 EDTA solution for 15 min,and determined by FAAS under the prescribed conditions.Detection limit (3s/k) of 2.1 μg·L-1 was found for the method.Precision was tested with 0.15 mg·L-1 of Mn(Ⅱ) for 6 determinations.Values of RSD (n=6) found was 3.4%.The proposed method was used for determination of manganese in samples of river water and ground water,and recovery was tested by standard addition method giving values of recovery in the range of 93.5%-99.7%.