The Method

What Is ICP-MS Heavy Metals Testing?

ICP-MS (Inductively Coupled Plasma Mass Spectrometry) is the analytical gold standard for heavy metals quantification, offering detection in the parts-per-trillion range. The technique works by atomizing and ionizing the sample in an argon plasma torch at approximately 8,000°C, then separating the resulting ions by mass-to-charge ratio in the mass spectrometer. Each element produces a distinct mass signature, allowing simultaneous quantification of 30 or more elements from a single sample introduction.

The four primary elements tested in dietary supplements — lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) — are all potent toxins with well-characterized dose-response relationships. Beyond the core four, expanded panels can include chromium, nickel, selenium, barium, antimony, and other trace elements required by specific regulatory frameworks or customer specifications.

Heavy metals testing matters because contamination sources are pervasive: botanical raw materials absorb metals from soil, manufacturing equipment can leach metals into products, and certain ingredient classes (seafood, rice, mineral supplements) carry inherently elevated exposure risk. Retailers, regulatory agencies, and consumers all require documented evidence of compliance.

1

Sample Preparation

Acid digestion (typically nitric/hydrochloric acid in a closed-vessel microwave system) fully dissolves the sample matrix, releasing all metal species into solution for analysis.

2

ICP Ionization

The digested sample is nebulized into an argon plasma torch at ~8,000°C. Every element in the sample is atomized and ionized with high efficiency, regardless of its original chemical form.

3

MS Detection

The mass spectrometer separates ions by atomic mass and counts them individually. Quantification against certified reference standards yields concentration values in µg/g or µg/serving at ppt sensitivity.

Why ppt Detection Limits Matter

California Prop 65's lead MADL is 0.5 µg/day — equivalent to 500 parts per trillion in a 1g serving. Only ICP-MS reliably and reproducibly measures at this level.

Compliance Context

Regulatory Standards for Heavy Metals

Multiple overlapping frameworks govern allowable heavy metals levels. The strictest applicable standard — typically California Prop 65 for U.S. brands — defines your testing and labeling obligations.

FDA Draft Guidance — Elemental Impurities in Dietary Supplements

Limits of 10 µg/day for lead and 15 µg/day for inorganic arsenic in adult dietary supplement products. Applies to finished products sold in the U.S. market. FDA has signaled intent to finalize this guidance and has cited heavy metals contamination in warning letters to supplement brands.

California Prop 65 — Lead MADL: 0.5 µg/day

The strictest U.S. heavy metals standard. The Maximum Allowable Dose Level (MADL) for lead is 0.5 µg/day. Brands selling into California must demonstrate that each serving delivers lead below this threshold or must display a Prop 65 warning. ICP-MS results reported in µg/serving are required to make this determination.

USP <232> Elemental Impurities — Limits

USP Chapter <232> sets permissible daily exposure (PDE) limits for elemental impurities in pharmaceutical products across oral, parenteral, and inhalation routes. While technically pharmaceutical standards, many supplement and nutraceutical brands use USP <232> limits as a quality benchmark.

USP <233> Elemental Impurities — Procedures

USP Chapter <233> specifies the analytical procedures for elemental impurity testing, designating ICP-MS as the primary reference method. Compliance with USP <233> requires validated method performance including LOD, LOQ, specificity, accuracy, and precision data.

EU Regulation EC No 1881/2006 — Contaminants in Food

Sets maximum levels for lead, cadmium, mercury, and inorganic tin in foodstuffs sold in the European Union. Relevant for supplement and food brands with EU distribution channels. Lead limits vary by food category: 0.02–0.30 mg/kg depending on the matrix.

Amazon / Whole Foods Retailer Requirements

Major retailers increasingly require COAs from ISO 17025-accredited labs for heavy metals in supplements and food products. Amazon's restricted products policy and Whole Foods supplier standards both reference third-party testing documentation. Our accredited COAs satisfy these requirements directly.

Who We Test For

Industries and Applications

ICP-MS heavy metals testing applies wherever elemental contamination is a regulatory, safety, or brand risk.

💊

Supplement Brands

FDA compliance, Prop 65 compliance, and retailer COA requirements for finished capsules, tablets, powders, and liquid products. Results reported in µg/serving for direct regulatory comparison.

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Natural Product Companies

Botanicals, herbs, and plant-derived ingredients carry elevated metal accumulation risk depending on growing region and soil conditions. Incoming raw material testing before manufacturing reduces finished product risk.

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Food Manufacturers

Seafood, rice products, leafy greens, and spices are regulated categories with defined lead and cadmium limits. ICP-MS documentation supports FDA compliance, export certification, and retail vendor programs.

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Water Testing

Drinking water, filtered water products, and industrial process water or effluent. EPA Method 200.8 (ICP-MS) is the standard for drinking water metals analysis. We also support bottled water brands seeking consumer-facing documentation.

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Environmental Monitoring

Soil, sediment, surface water, and groundwater analysis for site assessments, remediation monitoring, and regulatory reporting programs. Results formatted for regulatory submission packages.

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Pharmaceutical Companies

API and finished product elemental impurity testing per USP <232>/<233> and ICH Q3D guidelines. Method validation support and batch release testing for GMP-aligned product development programs.

Deliverables

What's Included in Your COA

Every heavy metals result is issued as an ISO 17025-accredited Certificate of Analysis. Results are formatted for direct use in regulatory submissions, retail compliance packets, and Prop 65 documentation.

  • Element-by-element results in µg/g and µg/serving (serving size required at submission)
  • Pass/fail vs. FDA / Prop 65 / USP limits — regulatory thresholds applied directly to results
  • Method reference — ICP-MS instrument, acid digestion procedure, and preparation details
  • LOD and LOQ for each element — confirms the method was sufficiently sensitive for the applicable limits
  • Percent recovery from matrix spike — QC data confirming method accuracy in your specific matrix
  • ISO 17025 accreditation statement with accreditation body reference and scope
  • Chain of custody documentation — sample receipt, handling records, and analyst signature

How to Submit a Sample

Container selection, preservation, and shipping requirements vary by matrix. Contact us before collecting.

1

Contact us first

Share your sample type, matrix, and quantity. We'll confirm appropriate containers, acid-free or metal-free collection requirements, and shipping instructions before you collect or ship anything.

2

Ship your sample

We provide a chain-of-custody form. Solids typically ship at ambient; liquids may require refrigeration. We receive samples at our San Diego facility and confirm receipt within one business day.

3

Receive your COA

ISO 17025-accredited results in 9–11 business days standard. Delivered digitally with all QC data and regulatory limit comparisons included.

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Common Questions

Frequently Asked Questions

What heavy metals are tested in dietary supplements?

The four primary heavy metals tested in dietary supplements are lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg). The FDA's Guidance for Industry on Elemental Impurities in Dietary Supplements, and USP <232> for pharmaceutical products, set limits for these four elements as well as additional trace elements including chromium, nickel, and selenium.

What are the FDA limits for heavy metals in supplements?

The FDA has issued draft guidance specifying limits of 10 µg/day for lead and 15 µg/day for inorganic arsenic in adult dietary supplements. California Prop 65 imposes stricter daily intake limits — the lead MADL (Maximum Allowable Dose Level) is 0.5 µg/day, making California compliance the most stringent U.S. requirement for most brands.

What is ICP-MS and why is it used for heavy metals testing?

ICP-MS (Inductively Coupled Plasma Mass Spectrometry) ionizes the sample in an argon plasma at ~8,000°C and detects each element by atomic mass. It offers detection limits in the parts-per-trillion (ppt) range — far below any regulatory limit — and can simultaneously quantify 30+ elements in a single analysis. It is the method of choice for heavy metals in the supplement, food, water, and pharmaceutical industries.

How do I comply with California Prop 65 for heavy metals?

To comply with California Prop 65, supplement brands must demonstrate that their product's lead content does not exceed the 0.5 µg/day MADL based on serving size. This requires ICP-MS testing with results reported in µg/serving, combined with serving-size documentation. If results exceed the threshold, a Prop 65 warning label is required on California-sold product.

What sample size is needed for heavy metals testing?

Heavy metals testing typically requires 1–5 grams of solid sample (capsule contents, powder, tablet) or 10–50 mL of liquid. Contact us with your sample format and available quantity — we'll confirm minimum requirements and container specifications before you ship.

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Ready to Test for Heavy Metals?

We'll confirm container requirements, preservation, and shipping instructions before you collect. Quote returned within one business day.

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