本文用微分脉冲极谱法测定空气中痕量甲醛,样品在含有硫酸肼的醋酸-醋酸钠缓冲体系中,于滴汞电极上产生灵敏的还原峰。实验结果表明:峰电压为—0.97V时,检测下限为0.001μg/ml;浓度在0.02—40μg/10ml范围内与峰高呈良好的线性关系;甲醛回收率为99.3％,吸收效率为98.5％,相对标准偏差为1.9％。 In this paper, the determination of trace formaldehyde in air by differential pulse polarography, the sample in the acetic acid - sodium acetate buffer system containing hydrazine sulfate, dropping mercury electrode to produce sensitive reduction peak. The experimental results showed that the detection limit was 0.001μg / ml when the peak voltage was -0.97V and the peak height was linear within the range of 0.02-40μg / 10ml. The recovery of formaldehyde was 99.3% and the absorption efficiency was 98.5% , The relative standard deviation of 1.9%.