Acid Digestion of Baby Food in Multiwave 7101/7301/7501 for the Trace Element Determination with ICP-MS Analysis

Since the ratio of food intake to body weight is significantly higher than later, infants and young children are more vulnerable to the effects of harmful food impurities. Therefore, legislation considers this population group as worth to be specifically protected.

Hence potential contaminants either originating from cultivation or further processing continuously are forced to be reduced to significant lower levels compared to other food products.

Currently as an example the Baby Food Safety Act of 2021 is under evaluation in the US Congress, aimed at low limits of inorganic arsenic, cadmium, lead and mercury for children up to an age of 36 months:

• Inorganic arsenic: 10 ppb  (15 ppb for cereals)
• Cadmium, lead:    5 ppb  (10 ppb for cereals)
• Mercury:              2 ppb

The Food and Drug Administration (FDA) shall periodically review and, if necessary, again lower these levels and additionally establish other toxic elements after inspection of relevant health and dietary data.

The initial action levels stated above should be met within one year after the date of enactment. In parallel to the evaluation of the Baby Food Safety Act the FDA already follows the “Closer to Zero action plan” with the goal to reduce dietary exposure to contaminants to as low as possible.

These legislative developments on the protection of young children pose a major challenge not only for the related agriculture and food industry, but also for the performance and quality of analytical methods and related equipment being applied in control laboratories.

In addition to the demand on measuring instruments to ensure extremely low quantification limits, preceding sample preparation also plays an important role in order to meet the high requirements for detecting such low concentrations reproducibly and correctly.

Highest purity of digestion vessels and the acids used are just as important as digestion conditions allowing the largest possible amount of sample together with the least possible amount of acid in order to keep interferences to a minimum.

Hereinafter we describe the successful digestion of eight representative infant and toddler food samples on Multiwave 7000 with quartz vials. Verification of the method is done by quantitative element analysis of two spiked samples by ICP-MS, using one dry product and one product with a higher water content.