AHMT分光光度法测定室内空气中甲醛的试验条件优化

Optimization of Experimental Conditions for Determination of Formaldehyde in Indoor Air by AHMT Spectrophotometry

室内空气甲醛含量测定的准确性至关重要.使用AHMT分光光度法测甲醛,优化吸收液稳定性、显色剂用量、显色温度和显色时间等试验条件,结果表明,吸收液可稳定5 d,最好现用现配,宜采用的试剂用量为KOH溶液1.10 mL,AHMT溶液0.90 mL,高碘酸钾溶液0.35 mL,在20~30℃条件下显色5 min后测定,20 min内测完,对应的校准曲线斜率符合方法灵敏度要求.经试验验证,方法检出限为0.050μg,RSD小于2%,加标回收率为97.44%~100.60%,均优于原方法.

It is very important to measure formaldehyde content in indoor air accurately.Based on the AHMT spectrophotometry,by optimizing the stability of the absorption solution,dosage of coloring agent,reaction time and heating temperature,the paper points out that the absorption solution can be stable for 5 days.The appropriate dosage of reagents is 1.10 mL of KOH solution,0.90 mL of AHMT solution,and 0.35 mL of potassium periodate solution.The measurement should be completed be in 20 min after coloring 5 min under 20-30℃.The slope of the corresponding calibration curve can conform to the sensitivity requirements of the method.The experimental verification shows that the detection limit of method is 0.050μg,the RSD is less than 2%,and the standard recovery is 97.44%-100.60%,which are better than the original method.