Overview
Al-Qadeeri and Abdullah measured lead and cadmium by AAS in 12 canned tomato paste products bought in Derna, Libya, after nitric acid digestion. Table 2 reports each product’s mean and SD in mg/L of the digest solution, not per kilogram of paste. The authors compare these values with limits they also quote in mg/L.
Key numbers
- Lead: “0.007±0.000” mg/L (STB 04) to “0.094±0.002” mg/L (STB 09) of digest (Table 2, p. 54).
- Cadmium: “0.001±0.002” mg/L (STB 11) to “0.090±0.002” mg/L (STB 08) of digest (Table 2).
- Three products (STB 05, 08, 09) are above the 0.05 mg/L cadmium limit the authors cite (Discussion, p. 55).
Methods (brief)
Half a gram of paste was heated with 25 mL water and 5 mL concentrated nitric acid until clear, filtered and diluted to 50 mL, then read by AAS. No detection limits, reference materials, recoveries or replicate counts are reported.
Evidence Fitness
The values are concentrations in the digest solution (0.5 g in 50 mL), so they are not mg/kg of paste and must not be compared with mg/kg rows or food limits; the extraction keeps them per litre. There is no QA, the replicate count is not stated, and several cadmium SDs exceed their means. Peer review is unverified. For barbecue-sauce this is a proxy: it measures tomato paste, not barbecue sauce, so that page is not linked.