Elemental Analysis Manual (EAM) for Food and Related Products
The U.S. Food and Drug Administration's (FDA) mission to maintain a safe food supply is met in part by monitoring food and related products for both toxic and nutritional elements. The FDA collects and analyzes food and other materials (foodware, vitamins, supplements, etc.) from commercial channels of trade to determine whether those materials are in compliance with applicable regulations. The analytical data gathered through these monitoring activities are also used for evaluating the extent and significance of these analytes in the food supply.
FDA laboratories perform these sample analyses using sound analytical practices and methodology which are documented in the Elemental Analysis Manual for Food and Related Products (EAM). This resource serves as a reference, for analysts at the FDA and around the world, providing not only general analytical information and procedures and detailed laboratory methods, but also helpful notes from analysts' experiences using these methods.
The content of the EAM is peer-reviewed on an on-going basis and endorsed by an Elemental Analysis Steering Committee. The analytical methods (in Section 4) have been successfully evaluated via at least a single-laboratory validation and are based on analytical procedures previously published in peer-reviewed scientific journals. For some of these methods, detailed proficiency information, obtained via multilaboratory studies, is also available and presented in appendices to the methods.
The EAM is not necessarily an exact representation nor an inclusive list of procedures used at FDA laboratories. Additional procedures (not in the EAM) may be used. Methods, for example, may be drawn from resources such as the Official Methods of Analysis of AOAC INTERNATIONAL and compliance programs issued by FDA may require specifically-tailored methods not published elsewhere. FDA field laboratories use a separate Laboratory Manual that provides guidance on primary laboratory functions. New methods and procedures are also developed as needed to respond to emergencies.
Please send any comments or contributions to EAM@fda.hhs.gov.
The mention of specific items of equipment and chemicals by brand name or the supplying of manufacturer's names and addresses do not constitute endorsement of a product or source by the United States Government.
If you are citing an EAM method or section, it is important to include the revision number, because methods are subject to review and improvement. Although you should follow the Author’s Instructions for your specific publisher, here is a sample citation for an EAM method:
Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic, Cadmium, Chromium, Lead, Mercury, and Other Elements in Food Using Microwave Assisted Digestion; FDA Elemental Analysis Manual [U.S. Food and Drug Administration, Internet]; Section 4.7, Version 1.2, 2020. Available from:
http://www.fda.gov/EAM (Accessed November 10, 2021).
Table of Contents
1. Elemental Analysis in FDA’s Food Program (PDF, 639KB)
1.1 Compliance & Enforcement
1.1.1 Compliance Resources
1.1.2 Compliance Programs
1.2 Chemicals, Metals & Pesticides in Food
1.3 Science & Research
1.3.1 Compendium
1.3.2 Method Validation
1.3.3 Quality Management
1.4 History
2. Sample Preparation
2.1 Food Edible Portion (PDF, 637KB)
2.1.1 General Procedures
2.1.2 Degasification of Carbonated Beverages
2.1.3 Contamination Control Measures
2.1.4 History
2.2 Food Homogenization (PDF, 841KB)
2.2.1 Laboratory Equipment
2.2.2 Homogenization Procedures
2.2.2.1 General Guidelines on Food Homogenization
2.2.2.2 Processing Heated Samples
2.2.2.3 Processing While Sample is Frozen
2.2.2.4 Addition of Liquid
2.2.3 History
2.3 Analytical Solution Preparation (PDF, 722KB)
2.3.1 Direct (“Dilute and Shoot”)
2.3.2 Extraction (Remove from Matrix)
2.3.3 Microwave Digestion (Eliminate Matrix)
2.3.3.1 Acid(s)
2.3.3.2 Analytical Portion Mass
2.3.3.3 Digestion Procedure
2.3.3.4 Incomplete Digestion
2.3.3.5 Digestion Vessel Cleaning
2.3.4 Speciation (Isolate Chemical Form; Yet to be drafted)
2.3.5 History
2.4 Contamination Control (PDF, 356KB)
2.4.1 Laboratory Environment
2.4.2 Analyst
2.4.3 Laboratory Ware
2.4.4 Laboratory Apparatus
2.4.5 Reagents
2.4.6 Blanks
2.4.7 History
3. General Analytical Operations and Information
3.1 Safety (PDF, 602KB)
3.1.1 Hazards
3.1.2 Safety Practices
3.1.3 History
3.2 Terminology (PDF, 796KB)
3.2.1 Figures of Merit
3.2.1.1 Performance
3.2.1.2 Detection
3.2.1.3 Quantitation
3.2.1.4 Sensitivity
3.2.2 Samples and Sample Solutions
3.2.3 Standard Solutions
3.2.4 QC/QA Materials and Solutions
3.2.5 History
3.3 Measurement Uncertainty (PDF, 826KB)
3.3.1 Types of Uncertainty
3.3.2 Sampling Uncertainty and Heterogeneity
3.3.3 Determining Analytical Uncertainty
3.3.3.1 Approaches
3.3.3.2 Uncertainty Budget Process
3.3.3.3 Uncertainty Components
3.3.3.4 Example - Uncertainty for One Analytical Portion
3.3.3.5 Example - Uncertainty for Multiple Analytical Portions
3.3.4 Uncertainty on a Report of Analysis (under development)
3.3.5 Uncertainty and Method Development - Example for Method 4.4
3.3.5.1 ASDL and ASQL
3.3.5.2 Uncertainty Budget
3.3.6 History
3.4 Special Calculations (PDF, 791KB)
3.4.1 Fortification Recovery
3.4.2 Other Recovery
3.4.3 Dilution Factor
3.4.4 Converting Units
3.4.5 Percent Difference
3.4.6 Mass Correction Factor (MCF)
3.4.7 History
3.5 Reference Materials (PDF, 760KB)
3.5.1 Matrix Reference Material Use for Quality Control
3.5.2 Reference Material for Instrument Calibration
3.5.3 In-house Reference Material Development
3.5.3.1 Selection
3.5.3.2 Analytical
3.5.3.3 Random Error and Homogeneity
3.5.3.4 Uncertainties
3.5.3.5 Instructions
3.5.4 Reference Material Re-verification
3.5.5 Reference Material Sources
3.5.6 In-house Reference Material Certificates
3.5.6.1 FDA Cocoa Powder (CP)
3.5.7 History
3.6 Performance (PDF, 1.04MB)
3.6.1 Instrument Performance (GFAAS)
3.6.1.1 Interferences
3.6.1.2 Peak Profile
3.6.1.3 Instrument Setup
3.6.1.4 Pre-standardization Checks
3.6.1.5 Standardization Verification
3.6.1.6 Analysis Checks
3.6.2 Instrument Performance (CV-GFAAS)
3.6.2.1 Interferences (Hg Example)
3.6.2.2 Instrument Setup
3.6.2.3 Pre-standardization Checks
3.6.2.4 Standardization Verification
3.6.2.5 Analysis Checks
3.6.3 Instrument Performance (ICP-OES)
3.6.3.1 Interferences
3.6.3.2 Instrument Setup
3.6.3.3 Pre-standardization Checks
3.6.3.4 Standardization Verification
3.6.3.5 Analysis Checks
3.6.4 Instrument Performance (ICP-MS)
3.6.4.1 Interferences
3.6.4.2 Instrument Setup
3.6.4.3 Pre-standardization Checks
3.6.4.4 Standardization Verification
3.6.4.5 Analysis Checks
3.6.5 Method Performance
3.6.5.1 Reference Material (RM)
3.6.5.2 Fortified Analytical Portion (FAP)
3.6.5.3 Fortified Analytical Solution (FAS)
3.6.5.4 Fortified Method Blank (FMB)
3.6.5.5 Laboratory MBK (MBKL)
3.6.5.6 Laboratory MBK Critical Value (MBKC)
3.6.5.7 Method Blank (MBK)
3.6.6 History
4. Analytical Methods
4.1 Flame Atomic Absorption Spectrometric Determination of Lead and Cadmium Extracted from Ceramic Foodware (Hight; No longer used at FDA)
4.2 Graphite Furnace Atomic Absorption Spectrometric Determination of Lead and Cadmium Extracted from Ceramic Foodware (Hight; No longer used at FDA)
4.3 Graphite Furnace Atomic Absorption Spectrometric Determination of Cadmium and Lead in Food Using Microwave Assisted Digestion (Mindak, Cheng Hight; No longer used at FDA)
4.4 Inductively Coupled Plasma-Atomic Emission Spectrometric Determination of Elements in Food Using Microwave Assisted Digestion (version 1.1; PDF, 1.4MB) (Dolan, Mindak)
- 4.4A Appendix A – Supplemental Information on In-house Method Validation (Mindak, Capar)
4.5 Cold Vapor Atomic Absorption Spectrometric Determination of Total Mercury in Seafood Using Microwave Assisted Digestion (Hight, Cheng Hight; No longer used at FDA)
4.6 Inductively Coupled Plasma Optical Emission Spectrometric Determination of Cadmium and Lead Extracted from Ceramic Foodware (version 1.0; PDF, 1.31MB) (Cheng)
- 4.6A Appendix A - Method Validation Report for EAM 4.6 Inductively Coupled Plasma - Optical Emission Spectrometric Determination of Cadmium and Lead Extracted from Ceramic Foodware (Heitkemper, Cheng)
4.7 Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic, Cadmium, Chromium, Lead, Mercury, and Other Elements in Food Using Microwave Assisted Digestion (version 1.2; PDF, 1.15MB) (Gray, Mindak, Cheng)
4.8 High Pressure Liquid Chromatographic-Inductively Coupled Plasma-Mass Spectrometric Determination of Methylmercury and Total Mercury in Seafood (version 1.0; PDF, 179KB) (Cheng, Hight)
4.9 Portable Hand Held X-Ray Fluorescence Determination of Toxic Elements (under development)
4.10 High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic Species in Fruit Juice (version 1.1; PDF, 1.35MB) (Conklin, Kubachka, Shockey)
- 4.10 Appendix A - High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic Species in Wine (Conklin, Kubachka)
4.11 Arsenic Speciation in Rice and Rice Products Using High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Determination (version 1.0; PDF, 292KB) (Various)
4.12 Inductively Coupled Plasma - Mass Spectrometric Determination of 18 Elements in Bottled Water (under development)
4.13 Inductively Coupled Plasma - Mass Spectrometric Determination of Iodine in Food Using Tetramethyl Ammonium Hydroxide Extraction (version 1.0; PDF, 595KB) (Todorov, Gray)
Glossary and Acronyms (PDF: 582KB)