本文介绍用无毒有效的氨基脲化氢氯作SO_2的吸收液,在酸性介质中加入对氨基偶氮苯和甲醛,生成桃红色的化合物,于505 nm处有最大吸收。仪器与试剂GS 865型分光光度计SO_2标准液:取0.2 g亚硫酸钠于250 ml蒸馏水中,此液约含SO_2 320～400 μg/ml,再用碘量法进行标定后稀释成适当的浓度。0.02%对氨基偶氮苯:此试剂须重结晶后用25%乙醇溶液配制。 In this paper, a non-toxic and effective amino-urea hydrogen chloride as SO2 absorption liquid, in the acidic medium by adding amino-azobenzene and formaldehyde, generating pink compounds, maximum absorption at 505 nm. Instruments and reagents GS 865 spectrophotometer SO_2 standard solution: Take 0.2 g of sodium sulfite in 250 ml of distilled water, this solution contains about SO_2 320 ~ 400 μg / ml, and then diluted with iodometry to an appropriate concentration. 0.02% p-amino azobenzene: This reagent should be recrystallized with 25% ethanol solution preparation.