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Fructose Concentration (
g/mL) = Fructose wt. (g) x 1,000,000
g/g x Purity
500 mL
Where: Purity = %Purity (from CoA)/100%
2.
Working standards –
Concentrations (in
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
g/mL, to a quadratic model (not forced through the origin).
Interpolate the sample concentration in
g/mL using the corresponding fructose response parameters. Calculate interpolated
sample concentration using the proper factors, as defined in 3.a -3.c.:
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)}
SW
1
= weight of material delivered to a volumetric flask (RTF, or reconstituted powder) and diluted as per sample table
guidelines. For example, a RTF product of 0.21-1.0% fructan would have a SW
1
of 7 g (±10%) into a 200 mL volumetric
flask.
SW
2
= weight of solution from volumetric flask per sample table guidelines (volumetric dilution of SW
1
). Value should be
0.2 g ± 10%.
PW
= weight of powder product weighed to be reconstituted (5 g ± 10%).
WW
= weight of water used to reconstitute powder products (40 g ± 10%).
b.
Dilution factor (DF)–
Calculated as follows:
Low-level fructan (RTF 0.03-0.2%, powder 0.27-1.0%)
DF = 50 mL
x
Commodity Factor x
2 mL
Mid-level fructan (RTF 0.21-1.0%, powder 1.1-10%)
DF = 200 mL
x
Commodity Factor x
2 mL
High-level fructan (RTF 1.1-5.0%, powder 11-45%)
DF = 500 mL
x
Commodity Factor x
2 mL
Commodity DF (46-100%)
DF = 1000 mL
x
Commodity Factor x
2 mL
c.
Commodity factors (CF) –
As in Table 2-4 (Type determined by qualitative ID methodology in Part 1 if not known).
FOS-04
FOR ERP USE ONLY
DO NOT DISTRIBUTE