Determination of Residual Formaldehyde in Urea-Formaldehyde Fertilizer and Formaldehyde Release from Urea-Formaldehyde Fertilizer During Decomposition

摘要

In view of the fact that a large amount of formaldehyde was involved in the production of urea-formaldehyde fertilizer, and the residual and decomposed formaldehyde has never been paid attention to. In this paper, the determination method of free formaldehyde content in urea-formaldehyde fertilizer was studied. A simple and accurate method for the determination of formaldehyde in urea-formaldehyde fertilizer was established based on the screening of traditional iodometry titration and acetylacetone colorimetry. The recovery rate of titration method and colorimetric method were 73.9-94.5% and 96.5-103.9%, which indicated that colorimetric method was more accurate. The optimized test conditions are as follows: fertilizer/water extraction ratio 1/20, developer acetylacetone 6 mL, the condition of reacting at 60 degrees C for 30 min. The linear range of formaldehyde content in urea-formaldehyde fertilizer determined by optimized method is 0.21-3.26 g/mL.