AOAC Gluten Quantitative Validation Guidance-Round 1(Nov 2023)

10 11 12

2.5g 1.5g 2.5g

40 min 40 min 20 min 30 min

75 C 75 C 75 C 60 C

15 min 15 min 15 min 20 min

High Low Low Mid

1:12 1:12 1:12 1:10

50 µ l

150 µ l 150 µ l 100 ml

N

2g

Table 6.

Varying 8 Parameters in a Plackett-Burman Design

Run

Sample Size

Extract. Time 40 min 40 min 20 min 20 min 40 min 20 min 20 min 20 min 40 min 40 min 40 min 20 min 30 min

Extract Temp

Sample Load 150 µ l 150 µ l 150 µ l 50 µ l 50 µ l 50 µ l 50 µ l 50 µ l 150 µ l 150 µ l 150 µ l 100 ml 50 µ l

Conjugate Dilution

TMB Time

Factor 7

Factor 8

1 2 3 4 5 6 7 8 9

2.5g 1.5g 1.5g 2.5g 1.5g 1.5g 1.5g 2.5g 2.5g 2.5g 1.5g 2.5g

75 C 45 C 75 C 45 C 45 C 75 C 45 C 45 C 45 C 75 C 75 C 75 C 60 C

25 min 25 min 25 min 25 min 15 min 25 min 15 min 15 min 25 min 15 min 15 min 15 min 20 min

High Low High High High Low High Low Low High Low Low Mid

High Low Low High High High Low High Low Low High Low Mid

1:8 1:8 1:8

1:12

1:8

1:12 1:12 1:12 1:12 1:12 1:12 1:10 1:8

10 11 12

N

2g

Table 7. Result Reporting

397 All results from the robustness study should be reported. Below is an example result table. This is a 398 result table from a full factorial design that varied 3 parameters, with 5 replicates per factorial pattern, 399 but a similar table design can be used for any size full-factorial or Plackett-Burman design. 400

Sample Size

Extract Time 20 min 20 min 40 min 40 min 20 min 20 min 40 min 40 min

Extract Temp

Test Portion Results – 20 ppm sample 1 2 3 4 5

Run

1 2 3 4 5 6 7 8

1.5g 2.5g 1.5g 2.5g 1.5g 2.5g 1.5g 2.5g

45 C 45 C 45 C 45 C 75 C 75 C 75 C 75 C

10 13

11 15 14 10 20 15 22 8

9

10 13

8

14 10 15 19 13 23 9

15

9

9

8

15

13

14

8

8

9

19 14 23

21 15 24

20 14 23

401

Table 8.

Study Analysis 402 Both the factorial and Plackett-Burman designs can be analyzed using a linear regression or factorial 403 ANOVA. 404 The following is an example of performing a factorial ANOVA on the data set in Table 8, using R and 405 RStudio. R and RStudio are free, open access programs that can be used online, or downloaded here. 406 Because RStudio works by writing lines of code, it is helpful to shorten the names of the column 407 headers. 408 In order to run the ANOVA, the data from Table 8 needs to be reoriented into a “long” format, with each 409 test result on its own individual row. When you enter the factor levels, remove any lettering or special 410 characters, and just enter the numbers. Figure 1 is an example of how this might appear on an Excel 411 sheet, but RStudio also allows you to upload data sets from text files and other statistics programs, or to 412 enter the data in manually (you can learn more about using RStudio here). However you save your 413