酚试剂分光光度法测定低浓度甲醛关键影响因素

Key factor of the determination of formaldehyde in low concentration by phenol reagent spectrophotometry

甲醛是主要的室内污染物,严重危害人体健康。准确测量甲醛,特别是低浓度甲醛的含量,对于室内甲醛的浓度测量和污染治理,具有不可替代的重要意义。酚试剂分光光度法检测甲醛具有试剂成本低、操作简单等优点,而且检出限、灵敏度、抗干扰程度等综合性能较好,是应用最多的甲醛检测方法。本研究采用国标GB/T 18204.2—2014推荐的酚试剂分光光度法检测甲醛的实验步骤为参考依据,采用控制变量法分别对盐酸、酚试剂、硫酸铁铵等试剂用量,温度、波长、时间等显色条件,以及硫酸铁铵溶液、酚试剂溶液稳定性等关键影响因素进行了系统考察,获得了甲醛检测的最优检测条件。并据此进行多次实验,绘制了代表性曲线,确定了该检测方法的灵敏度,测得该方法测定甲醛的检出限大约为0.061μg。

Formaldehyde is the main indoor pollutant,which is seriously harmful to human health.Accurate measuring the concentration of formaldehyde,especially the low concentration of formaldehyde,has irreplaceable significance for indoor formaldehyde concentration measurement and pollution control.Phenol reagent spectrophotometry has the advantages of low reagent cost,simple operation,and better detection limit,sensitivity,anti-interference,is the most applied formaldehyde detection method.This research refer the experimental procedure of phenol reagent spectrophotometry detect formaldehyde which recommended by national standard GB/T 18204.2—2014.The key influencing factors such as the dosage of hydrochloric acid,phenolic reagent,ammonium ferric sulfate and Color rendering temperature,wavelength,color rendering time and stability of ammonium ferric sulfate solution,phenolic reagent solution were investigated by control variable method,and obtained the optimal detection conditions for formaldehyde detection.Based on the above,representative curves were drawn by several experiments,and the sensitivity of the detection method was determined.The detection limit of this method for formaldehyde detection was about 0.061μg.