Candidates for 2016 ERP of the Year

Primary and Secondary Evaluation of Method OMAMAN-04

OMAMAN-04:

DETERMINATION OF FOLIC ACID IN FORTIFIED BOVINE MILK-BASED INFANT

FORMULA POWDER, FORTIFIED SOYA-BASED INFANT FORMULA POWDER,

FORTIFIED CEREALS, UNFORTIFIED CEREALS, VITAMIN TABLETS AND DIETARY

SUPPLEMENTS BY SURFACE PLASMON RESONANCE: COLLABORATIVE STUDY

Author(s):

Dr. Anthony O'Kane, MSB, Institute for Global Food Security (IGFS), Queens

University Belfast

Primary Reviewer:

John Szpylka

Secondary Reviewer

: Erik Konings

UMMARY OF

ETHOD

A collaborative study was conducted on an inhibition-based protein binding assay using the Biacore Q

biosensor instrument and the Biacore Qflex kit folic acid. The samples included infant formula, cereals,

premix, vitamin tablet, dietary supplement and baby food. Folic acid from samples within the matrix

scope is extracted into water utilizing sonication. Amylase and/or autoclaving are addition extraction

steps depending on the matrix. The remaining steps are not listed in the manuscript, but the

introduction section summarizes the measurement involving the a mixture of the extraction solution

and a competition solution being flowed across an HBS-EP folic acid sensor chip and the reduction in

signal measured by surface Plasmon resonance. The level of folic acid in the extraction solution is

calculated using external standardization.

ENERAL

OMMENTS

No mention of the method’s ability to detect or be influenced by the presence of naturally-occurring

folates. The study contained many errors demonstrated by the removal of 36 out of 198 data points

(18%). Omitted data should be listed with accompanying reasons. The removal of one of the duplicates

reported by the lab impacts determining the method's repeatability for the matrix being studied. Trace

folic acid levels were measured in the “blank” matrix by nine of the eleven labs (the other two were

“NA” for both replicates). Since the blank material was not tested for folic by an alternate method, the

source of the trace positives is unknown. Results from NIST 1849, Soy IF, and NIST 3244 are acceptable

in accuracy and precision (assuming the Soy if reference value is accurate – source not reported).

Results from the unfortified cereal appear accurate assuming the expected range is accurate – source is

not reported. The vitamin premix sample did not show acceptable accuracy or precision (assuming

accuracy based on independent measurement).

ROS

TRENGTHS

The assay employs simple extractions and rapid analyses.

ERP PROFILE SUMMARIES

190