萃取分离 ——三波长分光光度法测定农药废水中痕量硝基酚类

SELECTIVE EXTRACTION--DETERMINATION OF SMALL AMOUNTS OF NITROPHENOLS IN PESTICIDE WASTEWATER BY USING THREE WAVEIENGTHS PHOTOMETRY

本文采用三波长分光光度法同时测定了废水中三种痕量单取代硝基酚的含量。用乙醚作萃取溶剂,再用NH_3·H_2O-NH_4C1缓冲液从乙醚中反萃取硝基酚类并直接比色测定,计算机求解三元一次方程组,得到了三种硝基酚的含量,总萃取率可达96％以上。测定方法的相对误差为-1.25％～1.94％。并研究了影响萃取率的各种因素及样品加标回收等。该法适于废水中ppm级硝基酚的测定。

Mono-nitrophenols are extracted by ethyl ether, Its absorbances of reextraction with NH_4OH-NH_4C1 buffer(pH=10.20)is measured by three wavelengths photometry, and calculated by computer. The total amount of extraction is 96%. The range of relative error is in -1.25~1.94%. This method is especially suitable for the analysis of ppm level mono-nitrophenols in wastewater.