6. AOACSPIFANMethods-2018Awards

50

10 H ostetler : J ournal of AOAC I nternational V ol . 100, N o . 3, 2017

Table 2. Residuals and error of back-calculated concentrations for all- trans -lutein standard curves

Experiment 1

Experiment 2

Experiment 3

All- trans -lutein concn, μg/100 mL

Residual

Error, %

Residual

Error, %

Residual

Error, %

235.9 125.8

0.000368916 –0.003210486 0.00379152 0.000817163 –0.001767113

0.01 0.24

–0.000497233 –0.00122698 0.003308385 0.000644834 –0.002229005

–0.02

–6.16301E-05 0.00221285 –0.004609309 0.003230669 –0.00077258

0.00

0.09

–0.16

78.6 31.5 3.93

–0.44 –0.24

–0.38 –0.18

0.54

–0.93

3.78

4.65

1.65

Table 3. Residuals and error of back-calculated concentrations for all- trans -β-carotene standard curves

Experiment 1

Experiment 2

Experiment 3

All- trans -β-carotene concn, μg/100 mL

Residual

Error, %

Residual

Error, %

Residual

Error, %

227.4

0.00125077

0.05

0.002290766

0.09

–0.001591824

–0.06

121.3

–0.002520458

–0.18

–0.003680882

–0.27

0.00318571

0.23

75.8

–0.000366823

–0.04

–0.00193471

–0.23

–0.000338007

–0.04

30.3

0.001615483

0.47

0.002244522

0.65

0.000226108

0.06

3.79

2.10278E-05

0.04

0.001080305

2.33

–0.001481986

–2.97

Table 4. Calculated concentrations (μg/100 g) for all- trans -lutein and all- trans -β-carotene in the control formula (milk-based infant formula) using the original standard curve and using zero as the y -intercept

Experiment 1

Experiment 2

Experiment 3

Zero-intercept Orig. curve a

Diff ., % b

Analyte

Zero-intercept Orig. curve Diff., % Zero-intercept Orig. curve Diff., %

Lutein

4.5

4.4

–1.9

4.4

4.3

–2.9

4.4

4.4

–1.4

β-Carotene

13.1

13.0

–0.9

13.0

13.0

–0.3

13.0

12.9

–0.5

a  Orig. = Original. b  Diff. = Difference.

Table 5. Calculated concentrations (μg/100 g) for all- trans -lutein and all- trans -β-carotene in a FOS/GOS-fortified infant formula using the original standard curve and using zero as the y -intercept a

Experiment 1

Experiment 2

Experiment 3

Zero-intercept Orig. curve b

Diff., % c

Analyte

Zero-intercept Orig. curve Diff., % Zero-intercept Orig. curve Diff., %

Lutein

0.86

0.83

–3.5 –1.6

0.86

0.78

–8.8 –2.3

0.95

0.87

–8.3 –2.6

β-Carotene

3.3

3.3

3.3

3.3

3.6

3.5

a  FOS/GOS = Fructooligosaccharide/galactooligosaccharide. b  Orig. = Original. c  Diff. = Difference.

Table 6. LOD and LOQ for lutein in spiked SRM 1849a

Table 7. LOD and LOQ for β-carotene in spiked SRM 1849a

Measured concn, μg/100 g S/N

Extrapolated LOD, μg/100 g

Extrapolated LOQ, μg/100 g

Measured concn, μg/100 g

Extrapolated LOD, μg/100 g

Extrapolated LOQ, μg/100 g

Sample

Sample

S/N

1 2 3

1.40 1.46 1.43

68.6 70.4 37.0

0.06 0.06 0.12 0.08

0.20 0.21 0.39 0.27

1 2 3

1.62 1.70 1.66

61.6 61.2 61.0

0.08 0.08 0.08 0.08

0.26 0.28 0.27 0.27

 Average

 Average