99 / 159
FOR EXPERT REVIEW PANEL USE ONLY
NOT FOR DISTRIBUTION
2
Cons/Weaknesses
Dionex ion chromatograph with suppressed conductivity measurement needs experienced analysts
Standard dilution given in the SMPR is not followed (homogeneity of the test sample given by using
2,5 g test material?)
Supporting Data
General Comment:
–
Method Optimization: no remark
Performance Characteristics:
NIST 1894a Infant formula was used as reference sample
Chloride:
Analytical Range:
4 - 2400 mg/100g, shown by 3 independent tests with independent
prepared standard solutions
SMPR: 5 – 500 mg/100g reconstituted final product
(corresponds to 20 – 2000 mg/100g powder)
Linearity:
R
2
= 0.9995
SMPR: not required
LOQ:
0.02 mg/100 g
SMPR: ≤ 5 mg/100g reconstituted product
Accuracy/Recovery:
94,7 % – 106 %
SMPR: 95 % – 105 %
Except of two data points the SMPR is met
NIST: 12 determinations: recovery: 103 – 110 % (7207 – 7677 mg/kg)
NIST 1849a reference fraction mass for chlorine: 7010 mg/kg +/- 170 mg/kg
Precision (RSD
r
):
NIST SRM 1849a: 1.90 %
1,22 % – 3,16 % for SPIFAN samples
SMPR: ≤ 2 %
Reproducibility (RSD
R
): has to be determined in a multi lab study
System suitability: checked by analyzing daily standards at lowest and midpoint of the analytical
l range. System recalibrated, when percent error of the check standard is > 5 %
SPIFAN samples: 13 fortified SPIFAN samples were analysed and validation data are provided
Recommendation:
The method should be formulated manufacturer neutral.
Method cannot be recommended at first action status as the precision and the accuracy/recovery data do
not meet the SMPR requirements as well as the test sample amount (should be 25 g in 200 ml). But the
method has potential to get first action status after some adjustments resp. improvements.
Chlor-03/Fluor-02 Review Forms