Detection and characterisation of aluminium-containing nanoparticles in Chinese noodles by single particle ICP-MS

ABSTRACT

This study investigated Chinese noodles for the presence of aluminium-containing nanoparticles by using inductively coupled plasma mass spectrometry in single particle mode (spICP-MS) after enzymatic digestion by α-amylase. The aluminium concentrations in the noodle samples, determined by conventional ICP-MS without or with the use of hydrofluoric acid for digestion, were 5.4 ± 1.9 µg/g and 10.1 ± 2.2 µg/g (N = 21), respectively. Aluminium-containing nanoparticles were detected by spICP-MS in all 21 samples. Depending on the assumed particle composition, Al₂O₃ or Al₂O₃∙2SiO₂∙2H₂O, the median particle diameters were either below or above 100 nm, respectively. The minimum detectable particle diameter by spICP-MS was between 54 and 83 nm. The mass recovery of aluminium in the form of particles was between 5% and 18%. The presented work reports for the first time the detection of Al-containing particles in food by spICP-MS.

KEYWORDS:

• Aluminium
• acid digestion
• enzymatic digestion
• food labelling
• nanomaterials
• nanoparticles
• single particle ICP-MS

Acknowledgments

We thank Erik H. Larsen and Marianne Hansen for their assistance in planning and performing the work. This work was supported by University of Granada and CEIBiotic under the PhD international mobility programme.

Disclosure statement

No potential conflict of interest was reported by the authors.