Baś Bogusław, Jakubowska Małgorzata
Faculty of Materials Science and Ceramics, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland.
Anal Chim Acta. 2007 Jun 5;592(2):218-25. doi: 10.1016/j.aca.2007.04.030. Epub 2007 Apr 24.
In this paper, a quick and simple tensammetric method of estimation of non-ionic surfactants (NS) in aqueous solutions is proposed. The method makes use of the variation in the differential capacity of double layer in relation to the time of accumulation (C(d)-t(acc)) of non-ionic surfactants at the hanging mercury drop electrode, generated by a single, very quick opening of the valve. Under such conditions, the capacity current measured at the potential of maximum adsorption diminishes with accumulation time of non-ionic surfactants. The proposed method, which was verified for model surfactant (Triton X-100), may also be applied in the determination of other NS. Modifications in construction of the CGME electrode and its improved metrological parameters played an important role in the presented procedure. In addition, other measurements were performed using standard electrochemical techniques, whereby current-time and differential capacity-potential curves were recorded. Satisfactory results were obtained in the determination of Triton X-100 in the range from 0.05 to 20 mg L(-1) (R.S.D.=6%, recovery=94-103%, r=0.999, DL=0.15 mg L(-1)). Applicability of the method was presented using the water samples from Białka and Dunajec rivers, from which NS were removed by addition of fumed silica.
本文提出了一种快速简便的电位分析法，用于估算水溶液中的非离子表面活性剂（NS）。该方法利用了在悬汞滴电极上，通过单次快速打开阀门产生的非离子表面活性剂的积累时间（C(d)-t(acc)）与双层微分电容的变化关系。在这种条件下，在最大吸附电位下测量的电容电流随非离子表面活性剂的积累时间而减小。所提出的方法已针对模型表面活性剂（Triton X-100）进行了验证，也可用于测定其他NS。CGME电极结构的改进及其计量参数的改善在本方法中起到了重要作用。此外，还使用标准电化学技术进行了其他测量，记录了电流-时间曲线和微分电容-电位曲线。在测定Triton X-100时，浓度范围为0.05至20 mg L(-1)，获得了满意的结果（相对标准偏差=6%，回收率=94-103%，相关系数r=0.999，检测限DL=0.15 mg L(-1)）。通过添加气相二氧化硅去除比奥卡河和杜纳耶茨河的水样中的NS，展示了该方法的适用性。
