建立了二安替比林甲烷光度法测定硼铁中钛的方法,采用王水和氢氟酸分解样品,蒸至冒尽高氯酸烟后制备成硫酸介质溶液,用抗坏血酸将三价铁离子还原,随后在硫酸-盐酸介质中使二安替比林甲烷与钛形成黄色配合物,于波长385 nm处测定吸光度。对还原剂、显色剂和盐酸的用量及显色时间等条件进行了优化。最佳条件下,50 mL溶液中钛量在0~45 μg范围内线性良好,校准曲线线性方程为y=0.019 3x-0.004 02(y为吸光度,x为钛质量/μg),相关系数r=0.999 8,表观摩尔吸光系数为1.54×10⁴ L/(mol·cm);方法检出限为0.001%,定量限为0.003%;在3个不同钛含量水平下,精密度试验的RSD为 0.002 3%~0.012%;通过与ICP-AES法结果比对,所得数据准确可靠。该方法灵敏度高,选择性好,适用于硼铁产品质量控制、仲裁分析及标准物质/标准样品的定值等。

A spectrophotometric method using diantipyrylmethane (DAPM) was established for the determination of titanium in ferroboron.Samples were decomposed with aqua regia and hydrofluoric acid,evaporated to remove perchloric acid fumes,and dissolved in sulfuric acid medium.Ferric ions (Fe³⁺) were reduced with ascorbic acid,and titanium subsequently formed a yellow complex with DAPM in a sulfuric acid-hydrochloric acid medium.The absorbance was measured at 385 nm.The conditions for the reducing agent,chromogenic agent,hydrochloric acid dosage,and color development time were optimized.Under optimal conditions,titanium showed good linearity in the range of 0-45 μg per 50 mL solution.The calibration curve equation was y=0.0193x-0.004 02 (where y is absorbance and x is titanium mass in μg),with a correlation coefficient (r) of 0.999 8.The apparent molar absorptivity was 1.54×10⁴ L/(mol·cm).The limit of detection (LOD) was 0.001%,and the limit of quantification (LOQ) was 0.003%.The relative standard deviations (RSD) for precision tests at three different titanium content levels ranged from 0.0023% to 0.012%.The results were in good agreement with those obtained by ICP-AES,confirming the accuracy and reliability of the method.The proposed method is highly sensitive and selective,and is suitable for quality control,arbitration analysis,and certification of reference materials/standard samples of ferroboron products.