石墨炉原子吸收光谱法测定工业生产芳腈催化剂废水中钒

Determination of Vanadium in Industrial Wastewater Produced during Synthesis of Aromatic Nitriles by Graphite Furnace Atomic Absorption Spectrometry

基于含钒氧化物催化剂催化芳烃氨氧化反应制备芳腈化合物在工业上已经得到了应用,其中催化剂中活性组分钒含量流失进入产生的废水中是影响该反应性能的重要因素之一。应用石墨炉原子吸收光谱(GFAAS)法直接测定废水中钒含量,通过对样品预处理中酸介质、酸浓度和石墨炉升温程序中关键影响因素进行考察,实验表明采用硝酸(0.2%)加热消解,灰化和原子化温度分别采用500℃和1500℃时,效果良好。方法检出限为0.21μg/L,平行9次测试结果的相对标准偏差为2.5%,加标回收率为106%~109%,准确度好、精密度高,废水经简单的加热消解可直接进样测定,具有简便、操作快捷等优点。通过准确快速检测芳腈生产过程中产生的废水中钒的含量能够有助于评估工业装置在生产运行过程中的状态。

The synthesis of aromatic nitriles through aromatic ammoxidation reaction by vanadium-based catalysts has been widely utilized in industry.One of the important factors affecting the reactivity of the aromatic ammoxidation process is that the loss of vanadium ions due to entering into the wastewater,which is one of the products.Herein,the content of vanadium ions in the wastewater was directly detected by graphite furnace atomic absorption spectrometry(GFAAS).The key influencing factors of sample pretreatment and the heating program of graphite furnace were experimented and optimized.The results show that the best operating condition is to use 0.2%nitric acid for heating digestion,and 500℃and 1500℃for ashing and atomization,respectively.The detection limit of this method is 0.21μg/L and the relative standard deviation(n=9)is 2.5%with the spiked recoveries of vanadium in the range of 106%—109%.The sample was treated simply by employing heating digestion prior to analysis,and the results are reliable,which indicated that this method could be useful to rapidly evaluate and monitor the speciation of vanadium during the entire process of the complicated industrial reaction.