54 / 192
Example: AOAC Official Method 2015.03
Sodium Fluoroacetate in Infant Formula
Liquid Chromatography‐Tandem Mass Spectrometry
(LC‐MS/MS)
First Action 2015
[Applicable for the quantitative determination of sodium fluoroacetate in liquid and powdered milk‐ and
soy‐based infant formulas by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). The limit of
quantification (LOQ) of sodium fluoroacetate is 1 μg/kg by this method. Application of this method to
matrices not covered by the scope of application requires an additional validation.]
Caution: Material Safety Data Sheets (MSDS) should be available for all chemicals; inherent risks and
corresponding safety precautions shall be identified. Follow general safety precautions and environmental
aspects as described in the local Safety, Health and Environment rules in place.
A. Method Performance
The performance criteria in Table 2015.03A is prescribed by
Standard Methods Performance
Requirements
(SMPR)
2015.001
, 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 2015.03 verification data
.
Table 2015.03A Verification Criteria
B. Principle
Milk powder is first reconstituted in water. Liquid sample is used as such. Acetonitrile is added to
precipitate proteins. After centrifugation, the supernatant is washed with hexane and then acidified with
concentrated sulfuric acid. QuEChERS salts (MgSO4 and NaCl) are added for phase separation and the
mixture is centrifuged. The resulting supernatant is evaporated to 0.5 mL remaining volume and
centrifuged before LC‐MS/MS analysis in selected reaction monitoring (SRM) by electrospray ionization
(ESI) in negative mode. The compound is analyzed as its fluoroacetate anion.
Quantification is performed by the isotopic dilution approach using 13C labeled sodium fluoroacetate as
internal standard (IS). Positive identification of fluoroacetate in samples is conducted according to the
confirmation criteria defined in EU Commission Decision 2002/657/EC (1).
Parameter
Acceptance criteria
Analytical Range
4 ppb – 100 ppm*
Limit of Quantitation (LOQ)
≤ 4 ppb*
Accuracy
± 20%
Repeatability (RSDr)
≤ 14%
* Fluoroacetate expressed as μg of fluoroacetic acid /1000 g of
solids.
AOAC OMB Meeting
February 10-11, 2016
47