Overview
The authors measured lead, chromium, manganese, aluminum, copper, zinc and iron by MP-AES in 60 commercial mayonnaise and ketchup samples from the Iranian market, grouped by packaging (glass, plastic, sachet), and modeled intake under three diet scenarios. Average lead was 0.67 µg/g in mayonnaise and 0.51 µg/g in ketchup, several times the 0.1 mg/kg reference levels the authors cite. Cadmium and arsenic were not measured.
Key numbers
- Mayonnaise lead: 0.68 (SD 0.11) mg/kg glass-packed, 0.64 (0.16) plastic-packed, 0.69 (0.07) sachet-packed (Table 3).
- Ketchup lead: 0.54 (SD 0.09) mg/kg plastic-packed, 0.48 (0.06) sachet-packed (Table 3).
- Chromium: 0.24 to 0.64 mg/kg across groups; aluminum 0.65 to 1.70 mg/kg (Table 3).
Methods (brief)
Half a gram of sauce was digested with nitric acid and hydrogen peroxide on a hot plate and analyzed in triplicate by Agilent 4210 MP-AES. The lead LOD was 0.032 mg/kg and the LOQ 0.107 mg/kg. Spike recoveries at 50 mg/kg were 92 to 104 percent; no certified reference material is reported.
Evidence Fitness
A reasonable sample design (four brands, three production series per packaging type), but collection dates are not given, and the 50 mg/kg spike is far above measured levels. The text swaps the sauce labels for the highest zinc and lowest manganese compared with Table 3; findings follow the table. Mayonnaise and ketchup are measured directly here. They are only proxies for ranch-dressing, ranch-dressing-low-calorie, barbecue-sauce, pasta-sauce and brown-gravy, which are not linked.