Overview
Yan and colleagues developed a microwave digestion and ICP-AES method and applied it to four commercial dried jujube products from different Chinese locations. They report calcium, magnesium, manganese, iron, copper, aluminum and lead, while cadmium was not detected in any product.
Key numbers
- Lead: 3.1 (Xinjiang Hetian), 3.0 (Hebei), 4.2 (Xinzheng) and 3.6 (Huixian) ug/g, mean of replicates (Table 4).
- Aluminum: 32.0, 4.8, 50.6 and 15.9 ug/g in the same four products (Table 4).
- Cadmium: not detected in all four (Table 4).
Methods (brief)
Fruits were washed, pitted, oven-dried at 50 C and ground (dry basis), digested with nitric acid and hydrogen peroxide in a microwave system and analysed by ICP-AES. Spike recovery on one sample was 91.6 to 105% (lead 92%); no certified reference material was used.
Evidence Fitness
Weak occurrence evidence: one product per location, so the SDs reflect replicate digests, not variation between fruits. Lead at 3 to 4 ug/g is high for fruit and sits uneasily with the authors’ statement that toxic elements were low; Tables 2 and 3 print the same values with a ug/mL unit, so the units are not fully consistent. ICP-AES detection limits are given only in solution units. Use as supporting, not primary, evidence for the jujube-fruit page.