The analysis of minerals in foods, including macronutrients / micronutrients, trace elements and heavy metals, is a special type that requires a strong scientific background and knowledge of mineral and analytical chemistry, and skill.
To test for heavy metals (such as cadmium, lead, arsenic etc.) we use a method called “ICP-MS” (Inductively Coupled Plasma Mass Spectrometry) – one of the most reliable means of measuring trace elements such as lead reliably in a wide range of food products.
It measures the levels of trace elements like heavy metals in “parts per billion” (for reference, the standard limit in India for most products is in the “parts per million” range). This technique, a robust fit for purpose, internationally recognised method verified as per ISO 17025, is Nestlé’s official reference method for the quantitative determination of ten trace elements. It requires a highly qualified personnel to carefully follow the different steps of the method for each analysis while controlling the different critical parameters needed to deliver accurate results.
|1. Clean laboratory environment and labware
- Maintain an ultrapure environment
- Controlled temperature and humidity in the lab
- Ensure lab is free of dust, smoke and corrosive fumes
- Keep out of direct sunlight and away from heat
- Careful selection of non-lead labware
|2. Sampling and preparation of test samples
- Collect a representative test portion
- Avoid contamination from the external environment when preparing a test portion
- Use decontaminated digestion vessels
- Use pure acids (nitric, hydrochloric)
|3. Pressure digestion
- Avoid contamination of acids from dust and environment
- Carry out a blank test in parallel using the same procedure
- Ensure high pressure digestion with a closed vessel to avoid external contamination
|4. Preparation of the test solutions
- Dilute the sample appropriately to avoid interferences that could lead to incorrect results
- Filter if turbid and add digest test portion into appropriate test tube
- Use ultrapure water for dilution
|5. Equipment instrument set-up
- Check instrument (ICP-MS) performance by using tuning solution
- Use certified reference materials or proficiency test samples for quality control
|6. Calculations and expressions of results and internal control plan
- Check results of all analytes and confirmatory masses
- Report the result in mg/kg to 3 decimal places
- Include recovery data and blank test solution
View the latest test results.