How is elemental analysis used in food and agricultural testing?

Elemental analysis is used in food and agricultural testing to measure the concentration of specific elements in samples, including both essential nutrients and potentially harmful contaminants such as heavy metals. It helps producers, quality control labs, and regulatory bodies verify that food products and agricultural inputs meet safety and nutritional standards. The sections below address the most common questions surrounding this analytical discipline.

What elements are tested in food and agricultural samples?

Food and agricultural testing covers two broad categories of elements: nutritionally relevant minerals and potentially toxic contaminants. Essential elements such as calcium, magnesium, iron, zinc, potassium, and phosphorus are measured to verify nutritional composition. Toxic elements including lead, cadmium, arsenic, and mercury are monitored to ensure consumer safety and regulatory compliance.

The specific elements targeted depend on the sample type and its intended use. Cereal crops and leafy vegetables, for example, are routinely screened for cadmium because certain soils naturally accumulate it. Seafood is frequently tested for mercury and arsenic. Infant formula and baby food face particularly stringent elemental scrutiny because young children are more sensitive to trace contaminant exposure.

Agricultural inputs such as fertilizers, irrigation water, and animal feed are also subject to elemental analysis, since contaminants introduced at the production stage can carry through to the final food product.

Which analytical techniques are used for elemental analysis in food?

The most widely adopted techniques for elemental analysis in food testing are Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). ICP-MS is commonly used when ultra-trace detection is required, while ICP-OES is well suited to measuring major and minor elements across a broader concentration range.

Other techniques used in food laboratories include:

Atomic Absorption Spectrometry (AAS) for targeted single-element analysis of metals such as lead or cadmium
X-ray Fluorescence (XRF) for rapid, non-destructive screening of solid food matrices
Microwave Digestion combined with ICP for complete dissolution of complex food matrices before analysis
Ion Chromatography for speciation of elements such as arsenic, distinguishing between organic and inorganic forms

Method selection depends on the required detection limits, the number of elements to be measured simultaneously, throughput requirements, and the regulatory method specified for a given food category.

How does sample preparation affect elemental analysis results?

Sample preparation is one of the most critical steps in elemental analysis for food testing. Incomplete digestion, contamination during preparation, or analyte loss can all introduce significant errors into the final result, regardless of how precise the analytical instrument is.

Most food matrices require acid digestion to break down the organic material and bring trace elements into solution. Microwave-assisted digestion is widely used because it achieves complete dissolution under controlled temperature and pressure conditions, reducing the risk of volatile element loss. Dry ashing is an alternative for certain matrices but carries a higher risk of losing volatile elements such as mercury or arsenic.

Contamination from reagents, labware, or the laboratory environment is a persistent concern at trace and ultra-trace concentration levels. High-purity acids, cleaned vessels, and cleanroom preparation areas are standard practice in accredited food testing laboratories. Certified reference materials are routinely used to validate the entire preparation and measurement process.

What regulations govern heavy metal limits in food and agriculture?

Heavy metal limits in food and agricultural products are governed by a combination of international standards and regional regulations. In the Benelux region, food producers and laboratories work primarily within the framework of European Union regulations, which set maximum levels for contaminants such as lead, cadmium, mercury, and inorganic arsenic across a wide range of food categories.

The European Food Safety Authority (EFSA) periodically reviews the scientific evidence for contaminant exposure and advises on tolerable intake levels, which in turn inform regulatory updates. Codex Alimentarius standards from the FAO and WHO provide internationally referenced benchmarks used in trade and export contexts.

Agricultural regulations address heavy metal limits in fertilizers, sewage sludge applied to land, and irrigation water, recognizing that soil contamination is a primary pathway for heavy metals entering the food chain.

For exact compliance limits applicable to your product category, consult the relevant EU regulation, national competent authority guidance, or the applicable Codex Alimentarius standard.

Why do elemental results vary between labs testing the same sample?

Interlaboratory variation in elemental analysis results can arise from differences in sample preparation method, instrument calibration, the reference standards used, and the specific analytical technique applied. Even small differences in digestion efficiency or calibration curve construction can shift results meaningfully at low concentration levels.

Several factors commonly contribute to variability:

Digestion completeness varies with the acid mixture, temperature, and duration used, affecting how fully elements are extracted from the matrix
Calibration standards from different suppliers may have slight concentration differences that propagate through results
Matrix effects in ICP-MS can suppress or enhance signals depending on the dissolved solids content of the sample solution
Internal standard selection affects how well instrument drift is corrected during a run
Accreditation status of the laboratory influences whether validated, harmonized methods are consistently applied

Participation in proficiency testing schemes and use of certified reference materials are the primary tools laboratories use to identify and reduce systematic bias. Laboratories operating under ISO/IEC 17025 accreditation are required to demonstrate ongoing measurement competence through such programs.

How is elemental analysis applied in agricultural soil and crop monitoring?

In agricultural contexts, elemental analysis serves two distinct but connected purposes: monitoring soil fertility and detecting contamination that could affect crop safety. Soil testing for macronutrients such as nitrogen, phosphorus, and potassium guides fertilizer application decisions, while testing for trace elements identifies potential contamination from industrial activity, historical land use, or the long-term application of phosphate fertilizers.

Crop monitoring involves testing plant tissue at different growth stages to assess nutrient uptake and detect deficiencies or toxicities before they affect yield or quality. Cadmium accumulation in certain crops is a particular focus in European agricultural monitoring, given its persistence in soil and its tendency to accumulate in edible plant parts.

Water used for irrigation is also subject to elemental analysis, as contaminated water sources can introduce heavy metals directly into the root zone. Taken together, soil, crop, and water analysis form an integrated monitoring approach that supports both productivity and food chain safety from the field level upward.

How SciSPX supports elemental analysis in food and agricultural labs

SciSPX provides Benelux-based food producers, agricultural testing facilities, and quality control laboratories with the instrumentation and application expertise needed to run reliable elemental analysis workflows. The team combines high-end analytical instruments with hands-on support at every stage of the laboratory process.

Advice on instrument selection for ICP-MS, ICP-OES, and related techniques based on your specific matrix and regulatory requirements
Application-level support from product specialists who work alongside your lab team on method development and troubleshooting
IQ/OQ installation and validation services aligned with GMP and GLP requirements
Preventive and corrective maintenance to keep instruments performing within specification
Training for laboratory staff to get the most from their instrumentation

Whether you are setting up a new elemental analysis capability or looking to improve the reliability of an existing workflow, the SciSPX team is ready to help. Contact SciSPX to discuss your laboratory’s requirements.

Frequently Asked Questions

How do I know which analytical technique — ICP-MS or ICP-OES — is right for my food testing application?

The choice depends primarily on your required detection limits and the concentration range of the elements you need to measure. ICP-MS is the better choice when you need to detect elements at ultra-trace levels (parts per trillion), such as inorganic arsenic or mercury in infant food, while ICP-OES is more practical for measuring major and minor nutrients like calcium, magnesium, or iron at higher concentrations. Throughput, budget, and the regulatory method specified for your food category should also factor into the decision. Consulting with an application specialist before purchasing or commissioning an instrument can prevent costly mismatches between your workflow needs and instrument capability.

What is the biggest mistake food testing labs make during sample preparation, and how can it be avoided?

The most common and consequential mistake is incomplete acid digestion, which leaves residual organic matter in the sample solution and causes elements to be underreported or lost entirely. This is especially problematic at trace concentration levels where even a small recovery loss translates into a meaningful result error. Using microwave-assisted digestion with validated acid volumes, temperatures, and hold times — and always verifying recovery using a certified reference material alongside each batch — is the most reliable way to catch and correct this issue before results are reported.

How often should a food testing laboratory run certified reference materials, and which ones should it use?

Certified reference materials (CRMs) should be included in every analytical batch, not just during initial method validation. At a minimum, one CRM per matrix type per batch is considered good practice under ISO/IEC 17025, and many accredited laboratories run CRMs at the beginning and end of a sequence to bracket results and detect instrument drift. For food applications, matrix-matched CRMs from recognized producers such as NIST, IRMM (now EURL), or LGC are preferred because they reflect the complexity of real food matrices more closely than simple aqueous standards.

If our product is exported outside the EU, which elemental limits apply — EU regulations or Codex Alimentarius standards?

When exporting food products, the limits of the destination country or trading bloc take precedence, which means you may need to comply with multiple regulatory frameworks simultaneously. Codex Alimentarius standards serve as the internationally recognized baseline and are adopted directly by many countries that have not established their own national limits. In practice, it is advisable to identify the specific import requirements of each target market early in your compliance planning, as some countries maintain limits that are stricter than either EU or Codex thresholds for certain elements and food categories.

Can elemental analysis detect the difference between naturally occurring heavy metals in a food product and contamination introduced during processing?

Standard elemental analysis quantifies total elemental concentration and cannot by itself distinguish the source of that element. However, isotope ratio analysis using high-resolution ICP-MS and elemental speciation techniques can provide indirect evidence about origin in some cases. More practically, combining elemental data with a detailed knowledge of your raw material origins, processing steps, and packaging materials — and testing each stage separately — is the most effective way to identify where contamination is being introduced in a production chain.

How should a food producer interpret an elemental analysis result that is close to, but below, a regulatory maximum level?

A result near the regulatory limit should be treated as a risk signal rather than a simple pass, because measurement uncertainty means the true concentration could fall above or below the reported value. Accredited laboratories are required to report measurement uncertainty alongside results, and EU guidance recommends that this uncertainty be factored into compliance decisions. If a result sits within the measurement uncertainty band of the legal limit, the prudent response is to investigate the source of the element, consider additional testing of the batch, and consult with your regulatory advisor before releasing the product.

What steps should an agricultural producer take if soil testing reveals elevated heavy metal concentrations on their land?

The first step is to confirm the finding with a second round of sampling and analysis, ensuring representative sampling across the affected area, since soil contamination is often spatially variable. If elevated levels are confirmed, the next priority is identifying the contamination source — whether from historical industrial activity, long-term fertilizer application, or irrigation water — so the input can be addressed. Depending on the element and concentration, remediation options range from pH adjustment and phytoremediation to restricting the cultivation of accumulator crops such as certain leafy vegetables or cereals on the affected plots. Engaging with your national agricultural authority early is advisable, as some heavy metal soil thresholds trigger mandatory reporting obligations.

This content was generated with the help of AI and it may contain mistakes