6. AOACSPIFANMethods-2018Awards

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268 S CHIMPF ET AL . : J OURNAL OF AOAC I NTERNATIONAL V OL . 101, N O . 1, 2018

Table 1. Standard Method Performance Requirements a

uncertainty as possible into the method performance metrics. Samples were prepared by two analysts. New solutions and mobile phases were prepared every 1 – 2 days, and two sets of working standards were prepared during validation. To help establish method specificity, SPIFAN matrixes that were not fortified with carotenoids and were not expected to contain inherent carotenoids were prepared and analyzed to verify that no peaks were present in the lutein, b -carotene, and lycopene regions of the chromatograms. Previously established method performance requirements for lutein, b -carotene, and lycopene (SMPR 2014.014; 12) are summarized in Table 1. In late 2016 and early 2017, the SPIFAN carotenoid working group decided to split SMPR 2014.014 into four individual SMPRs; one for each of the carotenoids of interest. These individual SMPRs were approved by SPIFAN at the AOAC 2017 midyear meeting, but they have not been published yet. Single-Laboratory Acceptance Criteria

Parameter

Minimum acceptable criteria

1 – 1300 b

Analytical range

<1 b

LOQ

Recovery

90 – 110%

RSD r

1 – 100

8% 5%

>100 – 1300

RSD R

1 – 100

15% 10%

>100 – 1300

a Concentrations apply to ready-to-feed liquids as-is, reconstituted pow- ders (25 g into 200 g water), and liquid concentrates diluted 1:1 by weight. b Micrograms per 100 g reconstituted final product; range and LOQ are based on total of cis + trans isomers.

Lutein, b -carotene, and lycopene LOQs were determined experimentally by injecting low-level standards of known concentration and measuring the S/N. LOQs in standard solutions were calculated by multiplying the background noise by 10 and dividing by the sensitivity, which was defined as the ratio of the analytical signal to the concentration of the analyte producing the signal. Method LOQs in product were extrapolated from the standard LOQs using a typical sample weight and dilution volume. Ruggedness (or robustness) was not explicitly studied; however, several parameters relevant to this were varied during the single-laboratory validation in order to factor as much

Single-Laboratory Validation Results

Total lutein, b -carotene, and lycopene Standard Method Performance Requirements (SMPRs ® ) for repeatability and recovery were met for all SPIFAN matrixes with concentrations >1 µg/100 g RTF liquid, except one. The lutein repeatability data for the child elemental powder was

Table 2. Lutein precision data

cis -Lutein isomers, µg/100 g RTF

Total lutein, µg/100 g RTF

trans -Lutein, µg/100g RTF

RSD r

RSD r

RSD r

,

RSD R , %

,

RSD R

,

,

RSD R , %

n

%

%

%

%

Product description/Batch No.

Infant GOS/FOS powder/50350017W1 Infant elemental powder/00795RF Child milk powder 1/00866RF00 Adult low-fat powder/00859RF00

0.35 NA a

2.95

19.6

1.01 0.09 0.27 0.22 0.22

5.12 13.8 3.16 7.32 8.38

4.04 23.9 6.28 3.69 9.08

1.36 0.09 0.27 0.22 0.22

4.32 13.8 3.16 7.32 8.38

6.52 6 23.9 6 6.28 6 3.69 6 9.08 6

NA NA NA NA NA NA NA NA

NA NA NA

Infant hydrolyzed soy powder/410457651Z

Infant formula stage 1 milk powder/4044755861 SRM1849a powder/CLC10-B Infant milk powder/K16NTAV

NA

NA NA

8.41

3.78

1.93

8.41

3.78

1.93 5

NA NA

NA NA NA NA

0.13 5.06 8.06 30.4 3.56 2.15 14.2 16.7 24.2

13.1 1.89 2.91 3.46 3.37 5.42 2.44 2.94 2.01

16.5 3.03 8.50 7.26 4.44 6.22 4.65 10.5 22.9

0.13 5.06 12.0 36.5 5.36 6.65 16.7 2.45 25.5

13.1 1.89 2.45 3.57 3.26 5.58 2.88 2.92 1.93

16.5 6 3.03 6 8.06 12 6.91 12 3.77 12 5.20 12 4.96 12 4.45 12 4.97 12

Infant milk RTF 1/38300

3.95 6.10 1.80 4.51 2.45 0.60 1.32

4.02 4.18 3.35 6.50 6.14 4.64 4.42

8.52 11.9 3.07 5.78 10.4 4.58 4.26

SRM 1869 powder/CLC16-B

Adult high-protein RTF/ 00730RF00

Adult high-fat RTF/00729RF00

Adult high-fat RTF spiked/00729RF00

Infant soy powder/E10NWZC

Infant soy powder spiked/E10NWZC

Infant partially hydrolyzed milk powder/410057652Z

NA

NA NA

NA

NA NA

NA

NA NA 12

Infant partially hydrolyzed milk powder spiked/410057652Z

1.44

6.67

15.1

44.6

2.03

3.63

46.1

2.04

3.73 12

Infant milk RTF 2/EV4H2R

0.18 6.15

11.6 3.80

38.3 5.50

0.66 28.0

3.50 18.7

6.00 16.9

0.85 34.1

4.16 14.9

12.5 12 14.0 12

Child milk powder 2/4052755861

a NA = Not Applicable. No peaks detected.