AOACSPIFANMethods-2017Awards

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1390 Jaudzems: Journal of AOAC International Vol. 98, No. 5, 2015
INFANT FORMULA AND ADULT NUTRITIONALS
Received May 26, 2015. Accepted by SG July 2, 2015.
The method was approved by the Expert Review Panel on Infant
Formula and Adult Nutritionals as First Action.
The Expert Review Panel on Infant Formula and Adult Nutritionals
invites method users to provide feedback on the First Action methods.
Feedback from method users will help verify that the methods are
fit-for-purpose and are critical for gaining global recognition and
acceptance of the methods. Comments can be sent directly to the
corresponding author or
Corresponding author’s email:
DOI: 10.5740/jaoacint.15-136
A direct potentiometric method involving titration
against a standard volumetric silver nitrate solution
using a silver electrode to detect the end point
was evaluated for the determination of chloride
in infant formula and adult/pediatric nutritional
formula. It was assessed for compliance against
AOAC Standard Method Performance Requirements
(SMPR®) established by the AOAC Stakeholder
Panel on Infant Formula and Adult Nutritionals
(SPIFAN). A single-laboratory validation (SLV)
study was conducted as a first step in the process
to validate the method. In this SLV, 17 SPIFAN
matrixes representing a range of infant formula and
adult nutritional products were evaluated for their
chloride content. The analytical range was found
to be between 1.4 and 1060 mg/100 g reconstituted
product or ready-to-feed (RTF) liquid. The LOQ was
estimated as 1.4 mg/100 g. Method repeatability
was between 0.03 and 1.60% in the range of 20 to
167 mg/100 g RTF, and intermediate precision was
between 0.09 and 2.77% in the same range. Recovery
values based on spiking experiments at two different
levels of chloride ranged from 99.0 to 103% for 15
different SPIFAN products. Evaluation of trueness
was performed on National Institute of Standards
and Technology Standard Reference Material 1849a
(Infant/Adult Nutritional Formula) and showed 97.2%
of the theoretical value, with no bias at the 95%
confidence level. Based on the results of the SLV,
the method met the SMPR and was approved as a
First Action method by the AOAC Expert Review
Panel on Infant Formula and Adult Nutritionals
on March 17, 2015.
Apotentiometric method was evaluated to establish an
international consensus method for the determination of
chloride in infant formula and adult/pediatric nutritional
formula. StandardMethod Performance Requirements (SMPR®)
for chloride were approved by the AOAC Stakeholder Panel
for Infant Formula and Adult Nutritionals (SPIFAN) and are
described in AOAC SMPR 2014.015 (1). The single-laboratory
validation (SLV) was conducted on 17 SPIFAN matrixes and
a Standard Reference Material [SRM; National Institute of
Standards and Technology (NIST) 1849a Infant Formula/Adult
Nutritional Formula]. LOQ, precision, and accuracy were
assessed in this study.
On March 17, 2015, anAOAC Expert Review Panel (ERP) on
Infant Formula and Adult Nutritionals reviewed the SLV study
on the potentiometric method for determination of chloride and
adopted the method as AOAC Official MethodSM 2015.08. The
next step in the process will be to have a multiple laboratory
study performed using SPIFAN kits, after which the ERP may
recommend the method to the AOAC Official Methods Board
for Final Action Status (2).
AOAC Official Method 2015.08
Determination of Chloride
in Infant Formula
and Adult/Pediatric Nutritional Formula
Potentiometry
First Action 2015
[Applicable to the determination of chloride in ready-to-feed
(RTF) liquid concentrate and powder products from levels of
1.4 to 1060 mg/100 g reconstituted product or RTF liquids.]
See Tables 2015.08 A–C for the results of the SLV study
supporting acceptance of the method. The method was evaluated
against Standard Method Performance Requirements AOAC
SMPR 2014.015 (1).
A. Principle
Reconstitute powder samples by dissolving 25 g powder
sample in 200 g warm water (40°C). Add 50 mL of 2% (v/v)
nitric acid solution. Stir with a magnetic stirrer until mixed or
finely suspended. Ensure pH is <1.5. Titrate potentiometrically
against standardized silver nitrate (AgNO3) solution, 0.1 M,
using a silver electrode to detect the end point.
B. Apparatus
Common laboratory equipment and, in particular, the
following:
Determination of Chloride in Infant Formula and Adult/
Pediatric Nutritional Formula by Automated Potentiometry:
Single-Laboratory Validation, First Action 2015.08
Gregory G. Jaudzems
Nestlé Quality Assurance Center, 6625 Eiterman Rd, Dublin, OH 43017
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