177 / 620
Single Lab Validation Report for GOS in Infant Formula and Adult Nutritionals
11
Table 3: Method accuracy determined by spike-recovery experiments
Matrix
GOS
Spike level
(g / 100 g)
Recovery
(%)
RSD
(%)
Meets SMPR
Requirements?
7 (11750017V3)
Vivinal
0.02
91
11.5
Yes
Clasado
0.1
84
9.0
No
Vivinal
0.4
86
3.4
No
Clasado
0.6
85
5.0
No
10 (00394RF00)
Clasado
0.02
98
10.3
Yes
Vivinal
0.1
90
5.2
Yes
Clasado
0.4
87
4.3
No
Vivinal
0.6
88
6.6
No
11 (00412RF00)
Vivinal
0.02
90
18.5
Yes
Clasado
0.1
85
3.3
No
Vivinal
0.4
85
8.5
No
Clasado
0.6
84
2.8
No
12 (00403RF00)
Clasado
0.02
71
10.3
No
Vivinal
0.1
78
10.7
No
Clasado
0.4
86
4.1
No
Vivinal
0.6
84
9.3
No
Recoveries are generally in the range of 80 – 90%, which is lower than SMPR requirements (90 – 110%).
It is likely that part of the GOS is lost in the preparative step, in which lactose is removed, or in the SPE
purification. This, however, needs further investigation.
As stated before, because of confusion regarding sample preparation, the spiking levels were a factor 9
lower than anticipated. This could explain the higher RSD values for samples spiked at 0.02 g/ 100 g.
Because of the low spiking levels there was more background, which makes it more difficult to
determine the cut off point for fractionation. With higher spiking levels (and less background) the
window of the fraction, which is discarded in the preparative separation, can be narrowed. This may
improve recoveries.
If the LOQ is calculated based on blank measurements (following SMPR guidelines), the value is about
0.001 g / 100 g product. However, this does not seem “fair”, because this method uses a complex
calculation with an internal standard and subtracted values of the hydrolyzed and non-hydrolyzed
samples. The LOQ is estimated at 0.1 g / 100 g, which still meets the requirements of the SMPR (≤ 0.5 g
/100 g).
GOS-02 SLV
FOR ERP USE ONLY
DO NOT DISTRIBUTE