笑气-乙炔焰原子吸收光谱法测定氟石中氧化铝

N_2O-C_2H_2 Flame AAS for Determination of Aluminium Oxide in Fluorspar

报道了用笑气-乙炔火焰原子吸收光谱法测定氟石中氧化铝。试样经氢氟酸处理、高氯酸冒烟后，加入盐酸和硼酸温热溶解残渣。用富燃笑气乙炔焰在分析线A1309.3nm处，测定铝的吸光度。试验了溶样酸和酸度、硼酸、基体钙及共存元素对测定的影响。校准用的标准溶液系列中加入相同量的钙和硼酸作基体匹配。方法回收率96％～105％。本方法准确度、精密度满足商品检验的要求，已用于出口氟石的检验。

A method of N2O-C2H2 flame AAS for determination of aluminium oxide in fluorspar was established. The fluorspar sample was treated with HF and then fumed with HClO4 After cooling, the residue was dissolved by adding HCI and H3BO3 with gentle heating. Absorbance of the prepared solutions was measured at analytical line A1 309.3 nm using fuel-rich N2O-C2H2 flame. The standards for calibration were prepared by adding the same amount of Ca and H3BO3 into the test sample for matrix matching, Methods of decomposition of fluorspar by use of HF or no use of HF were experimentally compared. Acid concentration for sample decomposition, and effects of boric acid, matrix Ca and coexistent elements on AAS determination were experimentally tested. Recovery of the method was in rang of 96%-105 %. Accuracy and precision of method meets requirements of commodity inspection and the proposed method has been applied to the inspection of the export fluorspar.