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breakthrough of borate to the analytical column degrading method performance (primarily observed in the peak
asymmetry (EP) of the glucoheptose (also known as the USP tailing factor).
2.
Injection
–
A single 4 μL injection of each sample test solution is made. At the start of each sequence, 6 precision
injections are made to ensure that system is stable, followed by the 4 levels of working standard. Samples are
bracketed with working standards after every 13 injections. Autosampler is maintained at 10 °C.
3.
Electrochemical detector parameters
–
This method utilizes the carbohydrate triple waveform referred to in
Thermo/Dionex Tech Note 21, Waveform B (4).
Note this waveform is not appropriate for disposable gold
electrodes!
The reference electrode is set to AgCl mode.
4.
Retention times
–
Typically fructose elutes around 10-11 minutes and glucoheptose around 16-18 minutes (see figure
2-2 below).
Figure 2-1
Quantitative Fructan Determination Gradient
Table 2-5
Quantitative Fructan Determination Gradient*
Time (min)
Flow
(ml/min)
%C
%D
Curve
0
1.0
10.0
0.0
NA
0
1.0
10.0
0.0
5
20.0
1.0
10.0
0.0
5
20.1
1.0
80.0
20.0
5
30.0
1.0
80.0
20.0
5
30.1
1.0
10.0
0.0
5
45.0
1.0
10.0
0.0
5
*B line not used in this separation, remainder to make up 100% is from line “A” (lab water)
Fos-04 (February 2016)
FOR ERP USE ONLY
DO NOT DISTRIBUTE