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Figure 2-2
Working standard chromatogram
Additional chromatographic examples provided in Appendix B (including non-fructan containing SPIFAN matrices to
demonstrate specificity)
Calculations
1.
Fructose Stock Standard
–
Concentration is calculated as follows:
Eqn. #1:
Fructose Concentration (μ g/mL) = Fructose wt. (g) x 1,000,000 μ g/g x Purity
500 mL
Where: Purity = %Purity (from CoA)/100%
2.
Working standards
–
Concentrations (in μ g/mL) are as follows:
WS4 = Fructose stock * 50 /100
WS3 = Fructose stock * 25/100
WS2 = Fructose stock * 5/100
WS1 = Fructose stock * 5/
200
3.
Sample fructan (g/100g)
–
Obtain the peak areas for fructose and glucoheptose for each level of working standard. Fit
the peak area ratios (responses) and corresponding standard concentrations, in μg/mL, to a quadratic model (not forced
through the origin). Interpolate the sample concentration in μg/mL using the corresponding fructose response
parameters. Calculate interpolated sample concentration using the proper factors, as defined in 3.a -3.c.:
Eqn. #2:
Total Fructan (g/100g) = Interpolated fructose (in μg/mL) x DF (dilution factor) x CF(commodity factor)
SWF(sample weight factor)
a.
Sample Weight Factors (SWF)-
Calculated as follows:
RTF
:
SWF = SW
1
(g) x SW
2
(g) x 10,000
Commodity:
SWF
=
SW
1
(g) x SW
2
(g) x 10,000
Powder:
SWF
=
PW (g) x
SW
1
(g) x SW
2
(g) x 10,000
{
PW (g) + WW (g)}
Fos-04 (February 2016)
FOR ERP USE ONLY
DO NOT DISTRIBUTE