| Concentration and speciation of arsenic in Chinese Herbal Medicines (CHMs) from Hebei province (including samples from fields and markets) were investigated. Arsenic species in samples were extracted by 1% HNO3 combined microwave heating, then determined with HPLC-ICP-MS. Furthermore, an In Vitro gastrointestinal digestion established in this research was used to explore the bioaccessibility of inorganic arsenic in CHMs, eventually preliminary health risk assessment of total and inorganic As was also conducted. The main results showed that:1) Arsenic characteristics in CHMs and its preliminary risk assessment on human health The averages of As concentrations in different roots which were used as medicines, ranged from 0.14 mg/kg to 0.54 mg/kg, while for shoots which were used as medicines, average value of As concentrations in Dendranthema morifolium was 1.42 mg/kg, and the range in other species was from 0.09 mg/kg to 0.27 mg/kg. Based on Green Standards of Medicinal Plants and Preparations for Foreign Trade and Economy (2.0 mg/kg), the percentage of samples with As concentrations exceeding standard was 3.27%(n=153) in roots and 9.09%(n=44) in shoots, and 4.57%(n=197) in total CHMs samples.As concentrations in CHMs from field ranged from 0.03 mg/kg to 0.73 mg/kg, which were all lower than 2.0 mg/kg. However, As concentrations in CHMs from market ranged from 0.05 mg/kg to 7.05 mg/kg, and the concentrations of As in 6.36% of samples exceeded the limited standard. Arsenic concentrations in samples from market were significantly higher than those from field (P<0.05).As concentrations in Compositae were distributed widely from 0.08 mg/kg to 7.05 mg/kg, and the average at 0.87 mg/kg, while the averages of As concentrations in other six families were between 0.21 mg/kg and 0.41 mg/kg, and As levels in 75% of samples for each family were below 0.5 mg/kg. Compared to Compositae samples, the CHMs from other families have higher security.ADI regulated by FAO/WHO was used to assess As risk in CHMs on human health in this study as well. As daily intake through CHMs from market varied from 0.90μg/d to 19.7μg/d, and percentages of the daily intake of As in CHMs to ADI were in the range of 0.70% to 15.4%, which indicated that As in CHMs from market had a potential risk on human health after intake. 2) Inorganic Arsenic in CHMs and its preliminary risk assessment on human healthOn the basis of our findings, 1% HNO3 combined microwave heating was selected as the method used in extracting Arsenic species of CHMs.Inorganic As (Ⅲ) and As(Ⅴ) were the predominant species in CHMs. The proportion of inorganic As in speciation sum was over 86%. DMA was detected in 8% of samples, which were all from market, and the proportion of DMA was below 15%. MMA was detected in 10% of Anemarrhena asphodeloides samples at the concentration of 28μg/kg, and the proportion of MMA was 7%. Unknown As speciation was tested in a few samples from market and the percentage of this speciation was less than 10%.Concentrations of inorganic As in CHMs from field were between 62.7μg/kg and 550μg/kg (n=27), and the average was 209μg/kg, While the concentrations of inorganic As in samples from market were between 95.0μg/kg and 8683μg/kg(n=45), and the average was 1039μg/kg. The statistically significant correlations were found between total As in CHMs from field and market and their inorganic As, and correlation coefficients were 0.708 and 0.984, respectively.Intake daily associated with exposure to inorganic As from the consumption of CHMs from field were between 0.63μg to 5.50μg, which account for 0.49% to 4.26% of ADI value. Exposure to inorganic As from the daily consumption of CHMs could result in a dietary intake of range from 0.94μg to 86.8μg, and the percentages acount for ADI value were between 0.73% and 67.3%. The risk from consuming CHMs from market was significantly higher than it from the field samples (P<0.05).3) Bioaccessibility of inorganic arsenic in CHMsArsenic speciation in CHMs in In Vitro gastrointestinal digestion: Two species, inorganic As(Ⅲ) and As(Ⅴ), were detected in the gastrointestinal solution, and a few As(Ⅲ) in CHMs was oxidized to As(Ⅴ) in In Vitro gastrointestinal digestion. Likewise, only inorganic As(Ⅲ) and As(Ⅴ) was also tested in decoction of CHMs. Inorganic As in decoction at the stomach and intestine phase were significantly lower than those of CHMs at two phases (both P<0.05).Bioaccessibility of inorganic As in CHMs in In Vitro gastrointestinal digestion: Except that the bioaccessibility of inorganic As in A. asphodeloides and Trichosanthes kirilowii exceeded 100%, the range of other varieties were from 29.4% to 77.0% at the stomach phase, from 29.3% to 71.5% at intestine phase, respectively. Bioaccessibility of inorganic As in decoction of CHMs were between 3.35% and 18.9% at the stomach phase, between 6.31% and 18.4% at intestine phase. The bioaccessibility of inorganic As from consuming decoction and the health risk was decreased significantly (P<0.01). |
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