Pyrohydrolysis: a green sample preparation methodology for ion chromatographic analysis

Pyrohydrolysis is a sample preparation technique widely employed for the separation of fluorine, chlorine, bromine, iodine, boron and sulphur from solid samples which include refractive materials that are difficult to dissolve. A novel pyrohydrolysis procedure was developed for separating Mo directly from the solid uranium matrices and this is for the first time a metal is separated by this method. The separation is based on the volatilization of MoO₃.H₂O species at high temperature. The separated Mo was trapped as MoO₄² in dilute NaOH, which was further separated and determined by ion chromatography. The developed method is advantageous as it is simple and does not use acids and other organic reagents. The developed method was useful in the determination of Mo in ammonium diuranate samples, where the conventional methods suffer the loss of Mo. Pyrohydrolysis was also used for the simultaneously separation of B, F, Cl and Mo from the plant samples. The sample solution obtained after pyrohydrolysis was completely free from the organic matters like chlorophyll etc., which is amenable to ion chromatographic separation and determination of B, F, Cl and Mo