“…According to the physical or chemical principia in which the method is based, it can be classified into five main groups, as shown in Fig. 8: (a) classical chemical analysis [11,12,28,33,43], (b) spectroscopic techniques [10,11,17,44,45], (c) activation techniques [10,11,19], (d) electrochemical methods [14, [46][47][48][49][50], and (e) thermoanalytical techniques [11,18,51].…”