Revisiting some overlooked registered Thai traditional medicine preparations: an alert to a regulatory affair

Abstract

The chemical formula of the main component in each kind of crude drug obtained by X-ray diffractometer (Additional file 1: Figs S1–S7) and the weight percentages of the corresponding main elements determined by SEM–EDS are shown in Table 3. As anticipated, realgar and orpiment contained arsenic sulfide (AsS) and arsenic trisulfide (As2S3), respectively (Additional file 1: Figs S1, S2). Vermilion, natural vermilion, and cinnabar were composed of mercuric sulfide (HgS) as the main component (Additional file 1: Figs S5–S7). However, one vermilion sample did not detect any Hg or sulfur component. The XRD result revealed that calcium carbonate (CaCO3) comprised the main component. Moreover, no Pb existed in any Chinese powder samples, and all XRD results indicated that the primary component in each sample was calcium carbonate (CaCO3). One sample had the trace element hydrocerussite Pb3(CO3)2(OH)2. (Additional file 1: Fig S3). As anticipated, all Sen samples contained lead (II, IV) oxide (Pb3O4), and two showed trace amounts of lead (II) oxide (PbO). (Additional file 1: Fig S4). The SEM–EDS results were all consistent with the XRD results.