Abstract: Based on the principle of laser absorption spectrum and ultraviolet-visible spectrophotometer, a nitrite tester was built which takes use of the characteristics that the purple dye generated by the reaction of nitrite, amino benzene sulfonic acid and N-1-naphthyl ethylenediamine hydrochloride, specifically absorbs the 532 nm light produced by the semiconductor laser diode. It has been verified by the experiment that the absorption of the light beam by the purple dye had good linear relationship with the concentration of sodium nitrite within 0 to 1.4 ng/μL. Compared with the Griess reagent colorimetric method, the tester can obtain accurate results when it measures nitrite concentration in the natural water samples.

Key words: laser absorption spectroscopy, determination of nitrite, semiconductor laser

摘要： 结合激光吸收光谱和紫外–可见光分光光度计原理, 利用亚硝酸根和对氨基苯磺酸以及N-1-萘基-乙二胺盐酸盐反应后生成紫红色染料, 对绿色半导体激光管发出的532 nm 波长的光束有特异性吸收特性, 尝试制作一种激光亚硝酸盐测定仪。结果表明, 亚硝酸钠浓度在0~1.4 ng/μL 范围内, 上述紫红色染料对波长532 nm 的激光的吸收与亚硝酸钠含量呈良好线性关系。通过与经典格氏法平行对比, 结果表明该测定仪测定的自然水样中亚硝酸盐含量与经典格氏法测定的结果有很好的吻合度, 能够获得较高精度的测定结果。

关键词: 激光吸收光谱, 亚硝酸盐, 半导体激光