Bell Jérémy, Gotor Raúl, Rurack Knut
Bundesanstalt für Materialforschung und -prüfung (BAM);
Bundesanstalt für Materialforschung und -prüfung (BAM).
J Vis Exp. 2018 Nov 9(141). doi: 10.3791/58019.
Three fluorescent molecular rotors of 4-dimethylamino-4-nitrostilbene (4-DNS) were investigated for their potential use as viscosity probes to indicate the content of kerosene in diesel/kerosene blends, a wide-spread activity to adulterate fuel. In solvents with low viscosity, the dyes rapidly deactivate via a so-called twisted intramolecular charge transfer state, efficiently quenching the fluorescence. Measurements of diesel/kerosene blends revealed a good linear correlation between the decrease in fluorescence and the increase of the fraction of the less viscous kerosene in diesel/kerosene blends. Immobilization of the hydroxy derivative 4-DNS-OH in cellulose paper yielded test strips that preserve the fluorescent indicator's behavior. Combination of the strips with a reader based on a smartphone and a controlling app allowed to create a simple field test. The method can reliably detect the presence of kerosene in diesel from 7 to 100%, outperforming present standard methods for diesel adulteration.
研究了三种4-二甲基氨基-4-硝基芪（4-DNS）荧光分子转子作为粘度探针的潜在用途，以指示柴油/煤油混合物中煤油的含量，这是一种普遍存在的燃料掺假行为。在低粘度溶剂中，染料通过所谓的扭曲分子内电荷转移态迅速失活，有效地淬灭荧光。柴油/煤油混合物的测量结果表明，荧光的降低与柴油/煤油混合物中低粘度煤油比例的增加之间存在良好的线性相关性。将羟基衍生物4-DNS-OH固定在纤维素纸上得到了保留荧光指示剂行为的测试条。将这些测试条与基于智能手机的读取器和控制应用程序相结合，可创建一个简单的现场测试。该方法能够可靠地检测出柴油中7%至100%的煤油，优于目前检测柴油掺假的标准方法。
