AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

Fluor-03 (Feb. 2019) FOR ERP USE ONLY DO NOT DISTRIBUTE

Table 8 Overview of average results from the replicate QC analysis

Target concentration (µg/kg)

Number of analyzed samples

AVG F- (µg/kg)

SD F- (µg/kg)

RSD (%)

Recovery

QC ID

1 2 3 4

5

5.2

0.5 0.8 7.7

9.3 7.3 4.7 3.5

104 113 101

11 12 10 10

10

11.3

160 500

161.7 496.9

17.5

99

Figure 11 Replicate analyzes of the 5 μg/kg QC check standard measured in duplicate during the course of the method development. The system purity was checked by running several UPWs subsequently to samples and standards. In the blanks fluoride was not detectable and thus the system has no noticeable carry-over (see Figure 12 for an example UPW).

Figure 12 UPW carry-over check showing the UPW chromatogram (orange) and the 5 μg/kg standard (blue). In the UPW no detectable fluoride could be determined and thus carry-over excluded.

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