AVALIA??O DE DIFERENTES REAGENTES COLORIMéTRICOS PARA A DETERMINA??O DE FORMALDEíDO EM AMOSTRAS DE AR EM AMBIENTES INTERNOS

摘要

Different colorimetric reagents, the Nash reagent (acetylacetone/ammonia solution), Purpald (4-amino- 3-hydrazino-5-mercapto-1,2,4-triazole/sodium hydroxide solution) and 3-methyl-2-benzothiazolinone hydrazone (MBTH), were evaluated for the determination of formaldehyde in indoor air samples. Analytical parameters such as color stability of the product formed, sampling efficiency and reaction conditions were compared for the methodologies. Several method validation parameters were determined for the three colorimetric methods. The MBTH method showed better results and was used for the determination of formaldehydes in indoor environments.