Overview
Jia and colleagues built a solid sampling electrothermal vaporization atomic absorption method for cadmium in chocolate that needs no digestion, then applied it to 78 chocolate samples from nine producing countries bought on the Chinese market. Table 1 gives the minimum, maximum, mean, SD and median for each country, and Table 2 converts the means into hazard quotients.
Key numbers
- All 78 samples: mean cadmium 100.4 µg/kg (Table 1, p. 6).
- Chocolate produced in Russia (n = 9): mean 225.1 µg/kg, maximum 392.4 ± 4.2 µg/kg (Table 1, p. 6).
- Chocolate produced in Italy (n = 16): mean 44.2 µg/kg, median 40.1 µg/kg (Table 1, p. 6).
- Target hazard quotients were below 1 for every country even at 100 g of chocolate a day (Table 2, p. 7).
Methods (brief)
Ground chocolate (0.1 g) was dehydrated, ashed and vaporized in a nickel boat with an MgO-filled pyrolysis furnace, then cadmium was read by AAS. Method LOD 70 pg/g. A peanut powder reference material and microwave-digestion graphite furnace AAS were used for comparison; recoveries were 93 to 107 percent.
Evidence Fitness
Good analytical QA and a moderate retail sample, but cocoa content and chocolate type are not given and collection dates are not reported. Tables 1 and 2 disagree slightly on three country means, and the Methods list New Zealand where Table 1 lists France. This is plain chocolate, a proxy for chocolate-nut-candy, so that page is not linked.