**8.5 Physicochemical methods**

Physicochemical parameters include moisture content, total ash content, water soluble ash, acid insoluble ash and sulphated ash. These values of the individual drugs can be compared with the standard values of Indian pharmacopeia and thus their identity can be ascertained [41].

## **8.6 Spectral methods**

Spectral methods like infrared (IR) spectroscopy and ultraviolet- visible (UV–Vis) spectroscopic methods are extremely helpful structural elucidation of active constituents derived from botanical material. Not only structural elucidation but also its fingerprinting can be done by these techniques. They offer comparison between the natural and the synthetic compounds. Also, both qualitative and quantitative analysis can be done. Such techniques when integrated with chemometric tools like Principal Component Analysis (PCA) that help in handling multivariate data without prior knowledge about the study samples, becomes a boon [42, 43]. As chemometric analysis of spectral data does not require any chemical treatment, the method offers a rapid and simple analysis [44].
