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三氧化钨中钾钠含量是衡量产品质量的关键数据之一,因而要求准确度高。范健等采用以钝钨打底或用标准加入法抵消基体钨的影响。但到目前为止,钨基体的干扰仍未解决。为了消除基体的干扰,本文采用钨酸沉淀分离的方法,然后原子吸收分光光度法测定三氧化钨中的钾和钠。实验结果表明,基体钨对钾、钠的测定均产生负干扰,使吸光度分别降低约23％和19％。根据钨酸根在酸性介质中能沉淀为钨酸的原理,试验了盐酸、硫酸、硝酸和磷酸作为沉淀剂,结果以硝酸最好。实验选用1∶1硝酸8mL。干扰的消除:根据三氧化钨中杂质元素存在的情况,考查了20μg锑、铋;50μg砷、钙、镁、镉、铅、锰、硅、铜;100μg钒、钴、;200μg,镍、铬、钛;250μg铝;500μg铁,钼等对钾和钠测定的干扰,实验结果表明,这些元素在上述浓度时均没有干扰。三氧化
The content of potassium and potassium in tungsten trioxide is one of the key data to measure the quality of products, so it requires high accuracy. Fan Jian, etc. to use blunt tungsten backing or standard addition method to offset the impact of matrix tungsten. But so far the interference of the tungsten matrix has not been solved. In order to eliminate the matrix interference, this article uses the method of tungstic acid precipitation separation, and then atomic absorption spectrophotometric determination of potassium and sodium in tungsten trioxide. The experimental results show that the matrix tungsten negatively interfered with the determination of potassium and sodium, reducing the absorbance by about 23% and 19% respectively. According to the principle that tungstate can be precipitated as tungstic acid in acid medium, hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid were tested as precipitating agent. Nitric acid was the best. Experimental selection of 1: 1 nitric acid 8mL. Elimination of interference: According to the existence of impurity elements in tungsten trioxide, 20μg of antimony and bismuth were examined; 50μg of arsenic, calcium, magnesium, cadmium, lead, manganese, silicon and copper; 100μg of vanadium and cobalt; , Titanium; 250μg aluminum; 500μg iron, molybdenum and other determination of potassium and sodium interference, the experimental results show that these elements were in the above concentration without interference. Trioxide