新型甲醛被动式检气管的研制

Development of a Detection Tube for Formaldehyde Based on Passive Sampling

新研制的甲醛被动式检气管是建立在气体分子扩散和化学吸收原理基础上的。检气管内的惰性担体上浸渍了对甲醛特效的希夫试剂。当管内进入甲醛气体时，即发生显色反应，检气管的显色长度的平方与甲醛浓度及采样时间的乘积成线性关系。检出下限为０．０１５ｍｇ／Ｌ（采样５ｈ）。它集采样与分析为一体，结构简单，不需动力，便于携带和操作方便。应用于检测某厂刨花板车间和制胶车间的甲醛气体，与传统的注射器采样比色分析法对比，结果令人满意。检气管在避光条件下保存，保存期约为三个月。

A new detection tube for formaldehyde gas based on passive sampling has been developed according to the principle of the gas molecular diffusion and chemical adsorption.The tube contains inert materials impregnated with Shiffs solvation,which leads to a coloring reaction when in contact with formaldehyde diffusing into the tube.The square of coloring development length of the tube is direcly proportional to the product of the formaldehyde concentration and sampling time.The detection limit for formaldehyde is 0.015mg/L based on five hours of sampling.The method has been used for determining the concentrations of formaldehyde in formaldehyde storage rooms and particleboard workshops,with a relative error of ±10%.The shelf life of the tube is approximately three months without exposure to light.