纳米复合氧化物催化发光法测定空气中的甲醛

Determination of Formaldehyde in Air Utilizing Cataluminescence by Nanometer Composite Oxide

基于纳米复合氧化物上甲醛被催化氧化产生化学发光的现象,建立了直接测定空气中微量甲醛的方法.实验发现,甲醛在许多纳米级金属氧化物表面都有发光现象,但在纳米级钼钒钛(原子比为2∶3∶5)复合氧化物表面上有较高的发光强度和较好的选择性.最佳实验条件为:分析波长535nm,测定温度265℃,载气流速150mL/min.方法的检测限(3σ)为0.04mg/m3,线性范围为0.07～34mg/m3,相关系数为0.9994,回收率为98.2%～101.4%.对常见共存物的研究发现,除丙酮外,苯、氨、二氧化硫和乙醇不干扰测定.

A novel method based on cataluminescence （CTL） generated on the surface of a nanometer composite oxide was proposed for direct determination of formaldehyde in air. The CTL intensity and selec- tivity for the determination of formaldehyde on nano-MoO3-V2Os-TiO2 at an atomic ratio of Mo ： V ： Ti of 2 ： 3 ： 5 are bigger and better than those on other nanosized composite oxides. The optimum experimental conditions were tested for nano-Mo4V6Ti10047. Selective determination could be achieved at a wavelength of 535 rim. The surface temperature of the nanometer materials was about 265℃. The flow rate of air cartier was around 150 mL/min. The limit of detection of this method was 0.04 mg/m3. The linear range of CTL intensity versus concentration of formaldehyde was 0.07-34 mg/m3, and the correlation coefficient was 0.9994. The recovery of 6 testing standard formaldehyde samples by this method was 98.2%-101.4%. Common coexistence matters, such as benzene, ammonia, sulfur dioxide and ethanol, did not disturb the determination of formaldehyde, except acetone. This method allows rapid determination of formaldehyde in air.