Raw data: Leaching ratio (μg/g) of mercury from Tibetan medicine Zuotai,β-HgS and α-HgS in different pH solutions
Zuotai, a known Tibetan medicinal mixture containing insoluble cubic mercuric sulfide (β-HgS), has been used to treat diseases with long history. The mercury leaching ratio from Zuotai in gastrointestinal pH environment is one determinant factor for its bioavailability and biological effect. However, the information is still scarce now. Therefore, the study was designed to investigate the mercury leaching from Zuotai, β-HgS, and α-HgS in different pH solutions
Solutions with different pH values (1–13) were prepared from pure water, HCl solution, and NaOH solution; the pH was monitored using a pH meter. The solutions were as follows: HCl solution with pH = 1, HCl solution with pH = 3, HCl solution with pH = 5, NaOH solution with pH = 7, NaOH solution with pH = 9, NaOH solution with pH = 11, and NaOH solution with pH = 13. A solid-liquid ratio of 1:100 was adopted in all leaching experiments. Digestion, peristalsis and emptying of drug in the gastrointestinal tract were simulated in vitro. We detected the mercury released in solutions using Automatic Direct Mercury Analyzer. Leaching Ratio of Mercury (μg/g)=[Total Weight of Mercury Released (μg)]/[Total Weight of Substance Tested (g)]
The results showed that the mercury leaching ratios of Zuotai at pH 1 and pH 13 were significantly higher than those at each point within pH 3–11; the mercury leaching ratio of Zuotai at pH 1 was higher than that at pH 13. The mercury leaching ratio of β-HgS slightly decreased from pH 1 to pH 3 and significantly increased from pH 3 to pH 13. The mercury leaching ratio of β-HgS at pH 13 was far higher than that at pH 1. For α-HgS, the mercury leaching ratio also slightly decreased from pH 1 to pH 3 and then gradually increased from pH 3 to pH 13. The mercury leaching ratio of α-HgS at pH 1 was lower than that at pH 13.
Taken together, strong acidic or strong alkaline environments would promote the dissociation of mercury from Zuotai, β-HgS, and α-HgS.
