Description
This method describes determination of trace elements such as arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) at low concentration levels in all kinds of foods. The test solution, obtained by pressure digestion, is nebulised and the aerosol transferred to a high frequency inductively coupled argon plasma (ICP). The high temperature of the plasma is used to dry the aerosol and to atomise and ionise the elements. The ions are extracted from the plasma by a set of sampler and skimmer cones and transferred to a mass spectrometer where the ions are separated by their mass/charge ratio and determined by a pulsecount and/or analogue detector.
This NMKL method has been validated in a collaborative study published in Journal of AOAC INTERNATIONAL, Volume 90, Issue 3, 1 May 2007, Pages 844–856, https://doi.org/10.1093/jaoac/90.3.844.
IN Oct 2025 the calculation chapter was corrected in the method pdf, the number “1000” was removed from the denominator in the fraction, and included that the blanks should be subtracted in (a).
W = a · V · F/m
a: the content of the element in the test solution minus mean concentration in blank solutions (mg/L).
V: the volume of the digestion solution after being made up, in millilitre.
F: the dilution factor of the test solution.
m: the initial sample mass, in gram.