居室空气中甲醛含量的酚试剂分光光度测定法

目的建立居室空气中甲醛的测定方法。方法空气中甲醛用以水为吸收液的大型气泡吸收管吸收,与酚试剂反应生成吖嗪,吖嗪在酸性溶液中被高铁离子氧化生成蓝色化合物,根据颜色深浅比色定量。结果测定范围0．005—0．1mg／m^3,线性回归方程为Y=0．1909X＋0．0444,相关系数r=0．9998;相对标准偏差≤3．5％,加标回收率在92．0％～96．0％。结论方法操作简单,精密度和回收率好,适合居室空气中甲醛的测定。

Determination of Formaldehyde in Indoor Air by Spectrophotometry with Phenol Reagent

[ Objective] To establish a method for the determination of formaldehyde in indoor air. [ Methods ] The air sample was collected in the large bubble absorption pipette with water as absorbing liquid. The formaldehyde reacted with Phenol reagent, the generation of azine was oxidized to blue compound by high-iron ion. Quantitative colorimetrie accorded to the color depth. [ Results ] Determination range was 0.005 -0.1 mg/m^3 , linear regression equation was Y = 0. 1909X ＋ 0.0444 , correlation coefficient r = 0.9998, RSD ≤3.5%, recovery of standard addition was 92.0% N 96.0%. [ Conclusion] The method is simple, with good preci- sion and recovery, and suitable for the determination of formaldehyde in indoor air .