Overview
Wall and colleagues bought conventional and organic semi-skimmed milk and almond and oat plant-based beverages at UK supermarkets in summer 2023 and winter 2024 and measured macrominerals, trace elements and three heavy metals by ICP-OES and ICP-MS. Lead, aluminum and tin were below the limit of quantification in all products, and mercury was not measured. Results are least-squares means by ingredient, production system and season.
Key numbers
- Cadmium: cow milk 0.03 µg/kg, almond beverage 0.38 µg/kg, oat beverage 0.72 µg/kg (Table 1).
- Nickel: cow milk 45.9 µg/kg, almond 78.1 µg/kg, oat 157.9 µg/kg; chromium 42.7, 16.0 and 57.2 µg/kg (Table 1).
- Lead below the LOQ of 0.44 µg/kg in every product (Section 2.2).
Methods (brief)
One millilitre of product was digested with nitric and hydrochloric acid in a microwave system; ICP-OES for macrominerals and ICP-MS for trace elements. ERM-BD150 skim milk powder recoveries were 91 to 98% (copper 87%), with blanks and 30% duplicate analyses.
Evidence Fitness
A well-designed retail sample (96 products, two seasons, two production systems) with reference material control. Only means and pooled standard errors are given, and some cells print 0.00. The almond beverage results are direct for almond-beverage. The milk is pasteurised semi-skimmed (a UK reduced-fat milk); the paper does not give fat content per product.