酸性单偶氮染料共振散射法测定阳离子表面活性剂

Resonance Scattering Determination of Cationic Surfactants with Acidic Monoazo Dyes

建立了酸性单偶氮染料共振散射法测定阳离子表面活性剂的方法。结果表明,在1.1×10-2mol/L盐酸介质中,溴化十六烷基吡啶(CPB)分别与橙黄Ⅱ(OⅡ)、甲基橙(MO)及金橙Ⅰ(OⅠ)等酸性单偶氮染料反应形成相应的离子缔合物,使溶液的共振散射(RS)强度显著增强并产生相应的共振散射光谱,其最大散射峰分别位于278、281和277nm波长处。在一定范围内,CPB浓度与共振散射信号增强程度(△I)之间呈良好的线性关系。其检出限分别为1.91×10-9、7.61×10-9和6.91×10-10mol/L。该方法用于生活废水中阳离子表面活性剂含量的测定,结果满意。

The resonance scattering spectral characteristics and suitable reaction conditions of ion-association complex were studied. In the hydrochloric acid medium,cetylpyridinium bromide（CPB）reacted with orange yellowⅡ（OⅡ）,methyl orange （MO） and orangeⅠ（OⅠ）,respectively to form relative ion-association complexes,which made the intensity of resonance scattering enhance obviously and produced relative corresponding resonance scattering spectra. The largest scattering peaks were at 278,281 and 277 nm respectively. There were good linear relationships between the △I and the concentration of cetylpyridinium bromide（CPB） in certain ranges,and the detection limits were 1.91×10-9,7.61×10-9 and 6.91×10-10 mol/L,respectively. The method has been applied to the determination of the content of cationic surfactants in waste water with satisfactory results.