AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

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

(d) Instrument limit of detection (LOD/LOD FIN quantification) was determined on spiked UPW (UPW 0.5

). —The LOD (limit of detection) and LOQ (limit of

) as there was no measurable fluoride in the blanks, according to SPIFAN SLV Appendix L [2] . For the determination of the LOD a spiked UPW sample containing 0.5 μg/kg fluoride (for preparation see Table 3 ) was injected ten times (UPW 0.5 ) (see Table 9 ). The LOD (μg/kg) was calculated as following: = ( − ) �������� 0.5 + 3 × ( ( − ) 0.5 ) LOD (μg/kg) = Limit of detection determined for spiked UPW ( − ) �������� 0.5 (μg/kg) = Avergae concentration of fluoride in 10 spiked UPW (UPW 0.5 ) samples ( ( − ) 0.5 (μg/kg) = Standard deviation for fluoride in the 10 UPW 0.5 spikes The LOD FIN for the final product (LOD FIN in µg/100g) based on a UPW-mixture with 2.5 g sample per 50 g total weight is calculate by: = 100 × × 1000 × LOD FIN (μg/100g) = Limit of detection for the final product determined for spiked UPW LOD (μg/kg) = Limit of detection determined for spiked UPW W S (g) = Sample weight = 2.5 g (see chapter F) W UPW (g) = UPW weight = 50 g (see chapter F)

(e) Limit of quantification (LOQ/LOQ FIN

). —The LOQ FIN

was determined on base of the LOQ (see K. ) plus the 10-time standard deviation according

e; average concentration of the spiked UPW (UPW 0.5

to [2] :

= ( − ) �������� 0.5 + 10 × ( ( − ) 0.5 )

LOQ (μg/kg) = Limit of detection determined for spiked UPW ( − ) �������� 0.5 (μg/kg) = Avergae concentration of fluoride in 10 spiked UPW (UPW 0.5 ( ( − ) 0.5 (μg/kg) = Standard deviation for fluoride in the 10 UPW 0.5 spikes Related to the final product (LOQ FIN

) samples

) based on the sample-UPW mix with 2.5 g sample in a total

= 100 × × 1000 ×

volume of 50 g:

LOQ FIN (μg/ 100g) = Limit of quantification for the final product determined for spiked UPW LOQ (μg/kg) = Limit of quantification determined for spiked UPW W S (g) = Sample weight = 2.5 g (see chapter F) W UPW (g) = UPW weight = 50 g (see chapter F) The calculated LOD FIN for the final product of the proposed method is 1.3 µg/100 g and the quantification limit (LOQ FIN ) 1.6 µg/100g (see Table 9 ).

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