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Example: AOAC Official Method 2015.01
Heavy Metals in Food
Inductively Coupled Plasma–Mass Spectrometry
First Action 2015
Note
: The following is not intended to be used as a comprehensive training manual. Analytical procedures are
written based on the assumption that they will be performed by technicians who are formally trained in at least
the basic principles of chemical analysis and in the use of the subject technology.
{Applicable for the determination of heavy metals [arsenic (As), CAS No. 7440‐38‐2; cadmium (Cd), CAS No. 7440‐
43‐9; lead (Pb), CAS No. 7439‐92‐1; and mercury (Hg), CAS No. 7439‐97‐6] at trace levels in food and beverage
samples, including solid chocolate, fruit juice, fish, infant formula, and rice, using microwave digestion and
inductively coupled plasma–mass spectrometry (ICP‐MS).}
Caution
: Nitric acid and hydrochloric acid are corrosive. When working with these acids, wear adequate protective
gear, including eye protection, gloves with the appropriate resistance, and a laboratory coat. Use an adequate
fume hood for all acids. Hydrogen peroxide is a strong oxidizer and can react violently with organic material to give
off oxygen gas and heat. Adequate protective gear should be worn. Many of the chemicals have toxicities that are
not well established and must be handled with care. For all known chemicals used, consult the Material Safety
Data Sheet (MSDS) in advance. Etc., etc., etc.
A. Method Performance
The performance criteria in Table 2015.01A is prescribed by
Standard Methods Performance Requirements
(SMPR)
2012.00
7
, which was adopted by the AOAC Stakeholder Panel for Dietary Supplements (SPDS). Laboratory(ies)
implementing this method should follow ISO Standard 17025 to verify that the performance of this method in your
laboratory meets the criteria in Table 2015.11A. Please report verification results to AOAC at this link:
AOAC
2015.01
.
Table 2015.01A Verification Acceptance Criteria
Limit of Quantitation (LOQ)
Parameters
Ranges
Repeatability (RSD
r
)
Recovery
≥ 10 ppb to 100 ppb
≤ 15%
60% ‐ 115%
>100 ppb to 1 ppm
≤ 11%
80% ‐ 115%
> 1 ppm to 10 ppm
≤ 7.3%
80% ‐ 115%
B. Principle
Food samples are thoroughly homogenized and then prepared by microwave digestion and the addition of dilute
solutions of gold (Au) and lutetium (Lu). The Au is used to stabilize the Hg in the preparation, and the Lu is used to
AOAC OMB Meeting
February 10-11, 2016
46