Picrate

About: Picrate is a research topic. Over the lifetime, 1834 publications have been published within this topic receiving 24405 citations. The topic is also known as: picrates.

A novel picric acid film sensor via combination of the surface enrichment effect of chitosan films and the aggregation-induced emission effect of siloles

Abstract: A novel fluorescent film was fabricated by doping the aggregates of hexaphenylsilole (HPS) into a chitosan film. It was demonstrated that the fluorescence emission of the film is stable, sensitive and highly selective to the presence of picric acid (PA). The detection limit for PA is about 2.1 × 10−8 mol/L. Introduction of 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), nitrobenzene (NB), phenol, benzene, toluene, methanol, ethanol, and zinc nitrate (Zn(NO3)2) had little effect upon the fluorescence emission of the film. The selectivity of the film was attributed to the specific electrostatic association effect of the protonated substrate film to picrate anion and the screening effect of the film to the interferents. The network structure of the substrate film is also favourable for the stabilization of the fluorescence emission of the hybrid film, by preventing the further aggregation of silole aggregates. Fluorescence lifetime measurements revealed that the quenching is static in nature. Furthermore, the quenching process is fully reversible. Considering the simplicity of the preparation and the outstanding performance of the hybrid film, it is anticipated that it could be developed into a real-life PA sensor.

Picrate paper kits for determination of total cyanogens in cassava roots and all forms of cyanogens in cassava products

Abstract: The simple semiquantitative picrate method for the determination of total cyanogens in cassava flour has been modified by increasing the concentration of the picrate solution used to make up the picrate papers, such that a linear Beer's Law relation between absorbance and cyanogen content is obtained over the range 0–800 mg HCN equivalents kg−1 cassava The method has been adapted to determine the total cyanogen content of cassava roots and the results compared using the picrate method and the acid hydrolysis method for six different roots from five cultivars The agreement between the results is satisfactory The simple method for determination of total cyanogens in cassava roots in the field is available in kit form The methodology has been modified to allow determination of the three different forms of cyanogens present in cassava flour, viz HCN/CN−, acetone cyanohydrin and linamarin HCN/CN− is determined by the picrate method in which cassava flour is reacted with 01 M sulphuric acid for 3 h at room temperature HCN/CN− plus acetone cyanohydrin is also determined by the picrate method after treating cassava flour with 42 M guanidine hydrochloride at pH 8 for 3 h at room temperature A comparison has been made of the amounts of the three cyanogens present in six cassava flour samples using the semiquantitative picrate and the acid hydrolysis methods The agreement between the two methods is satisfactory, which shows that the new methodology works well The picrate method for determination of the three cyanogens in cassava flour is also available as a kit © 1999 Society of Chemical Industry

Fluorescent tris-imidazolium sensors for picric acid explosive.

Abstract: Two new anthracene-functionalized fluorescent tris-imidazolium salts have been synthesized, characterized, and proven to be selective sensors for picric acid, which is a common constituent of many powerful explosives. Theoretical studies revealed an unusual ground-state electron transfer from picrate anion to the sensor molecules.