AOAC OMB Final Action Recommendation (December 2019)-2016.14
FOS-03 FOR WORKING GROUP/ERP USE ONLY DO NOT DISTRIBUTE
and re-equilibrated for 10 min with 5.1 mM sodium hydroxide before the next injection (see
table below for details).
Post column addition - 300 mM sodium hydroxide is introduced at a flow rate of 0.6 mL/min
via a T-piece between the column and the PAD detector.
Injection – A single 20 μL injection is made of each sample test solution. At the start of each
series two blank (water) injections of 20 μL are made to stabilise the system, followed by a
20 μL injection of standard solution. A 20 μL injection of the standard solution is made after
every 6 sample injections and at the end of the series.
Retenetion times – Retenetion times are controlled by comparing that of the standard with
that of the sample. Typically fructose elutes at around 36 minutes.
Method for LC determination of fructose
Time (min)
% A (NaOH, 300mM)
% B (water)
Comment
0
1.7
98.3
Start
45
1.7
98.3
Finish isocratic elution
45.1
100
0
Start column wash
55.0
100
0
End column wash
55.1
1.7
98.3
Start re-equilibation
65.0
1.7
98.3
End re-equilibration
G. Calculations
The concentration of the fructose standard is calculated as follows:
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