Overview
Santos and coauthors measured total arsenic, cadmium, and lead in 104 yerba mate samples marketed in three southern Brazilian states. Cadmium was the main compliance signal: many samples exceeded Brazil’s 0.4 mg/kg ANVISA cadmium limit, while arsenic remained below the cited 0.6 mg/kg limit. The source is occurrence evidence for dried yerba mate leaves used in herbal infusions, not mineral water.
Key numbers
The authors report As, Cd, and Pb in yerba mate leaves as mg/kg.
| State | n | tAs mean +/- SD | Cd mean +/- SD | Pb mean +/- SD | Reported ranges |
|---|---|---|---|---|---|
| Rio Grande do Sul | 77 | 0.03 +/- 0.01 mg/kg | 0.59 +/- 0.20 mg/kg | 0.41 +/- 0.23 mg/kg | As 0.015-0.033; Cd 0.18-1.25; Pb 0.10-1.20 mg/kg |
| Santa Catarina | 11 | 0.06 +/- 0.03 mg/kg | 0.42 +/- 0.19 mg/kg | 0.29 +/- 0.09 mg/kg | As 0.015-0.114; Cd 0.25-0.71; Pb 0.20-0.54 mg/kg |
| Parana | 16 | 0.056 +/- 0.03 mg/kg | 0.47 +/- 0.15 mg/kg | 0.44 +/- 0.10 mg/kg | As 0.015-0.15; Cd 0.21-0.72; Pb 0.25-0.70 mg/kg |
The abstract summarizes whole-study ranges as tAs 0.015-0.15 mg/kg, Cd 0.18-1.25 mg/kg, and Pb 0.1-1.20 mg/kg. The authors state that Cd exceeded 0.4 mg/kg in 84% of Rio Grande do Sul samples, 63% of Parana samples, and 75% of Santa Catarina samples; pooled across the full 104-sample set, 74% exceeded the 0.4 mg/kg Cd limit. Pb was unsatisfactory in 7% of Rio Grande do Sul samples and, per the abstract, 5% of Parana samples; the Discussion text reports the underlying Pb-exceedance counts as five samples in Rio Grande do Sul, three in Parana, and zero in Santa Catarina, so the Parana figure is closer to 19% (3 of 16) than the 5% printed in the abstract.
Methods (brief)
Concentrations reported in the key-numbers table reflect total acid digestion: approximately 0.5 g of each ground sample was digested in Teflon tubes with 2 mL deionized water, 2 mL concentrated nitric acid, and 2 mL hydrogen peroxide in a closed-vessel microwave (Berghof SpeedWave), then diluted to 25 mL prior to analysis by ICP-MS on a PerkinElmer NexION 300D with rhodium as internal standard. The method detection limits were 5.5 ng/L for As, 4.9 ng/L for Cd, and 43 ng/L for Pb, with reported recoveries of 104%, 109%, and 114%, respectively. A separate sub-experiment simulated the chimarrao infusion (about 1.5 g in 10 mL of 80 C deionized water, 5 minutes, centrifuged); approximately 10% of the Cd and 5% of the Pb in the dry leaf transferred to the infusion supernatant, and infusion As was below the method limit of quantification.
Implications
Certification: The paper supports herbal-infusion ingredient evidence for Cd and Pb in yerba mate leaves, with Brazilian market geography preserved.
Courses: The study is a useful example of jurisdiction-specific herb and infusion evidence where total arsenic is measured but inorganic arsenic is not speciated.
App: The values can inform a Brazil-specific yerba mate or herbal-botanical flag after synthesis decides how to represent a commodity without a dedicated ingredient page.
Related evidence
Update history
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