AOAC-RI ERP Book - Gluten.pdf

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Table 14. Data summary of gluten-free and spiked rice
cereal
I-rípo r,,r' At-.: JoutìNAr. oF AOAC IN il'tìNArroNl\t, VoL. 96. No. 1. 20 Ii til
Table 16. Data summary of gluten-free and gluten-
incurred bread
Spike levels. ppm 10 Spike levels. ppm 0 5 10 20
[,4ean, ppm O.4'l
Mean recovery, % NAa
RÞôêâtâh;¡;lw Sn n Ã?
Repeatability RSD, % NA
No. of replic€tes w¡th
acceptablerecovery' l\A
LOD, ppm 2-16
LOQ, ppm 5.71
Mean RSD, % 22.50
Mean recôvêru o/,, 10? 6,n
5.74 9.4'l
114.70 94.10
0.92 2.37
16.03 25.19
10120 18120
20.6 39.25
'f03.1 0 98.1 0
4.94 9.26
24.18 23.59
19/20 20120
' NA = Not applicable-
b The actual percentages are presented ¡n Table '1O.
Lot-to-Lot Variability and Stability
Loþto-lot variabilitl,' is assessed b)' testing samples ol'spiked
gluten-lì-ee rice at 3 levels (0. 5. and l0 pprn). Results \\'ere tâken
fiom a standard curve. Assavs rvere perl'onned in triplicate for
each of three diIìèrent kit lots. 'fhe three kit lots represented
reagents at the beginning. nriddle. and end ofusable shelflifè.
(a\ Tesling.-'l-he above preparations rvere tesled f'olloling
tlre plocedure set fbtlh in Sample Preparation ¿tnd Ertrac.tion,
ProcetluraI Ïr¡les, Precautions, Anub,sis, and Interprefation of
Rcslr//s sections of this docunrenl.
(b) Re.rrrlls.-Results scnerated liorn each lot of kits u,ere
f'ound to be con.rparable (làble 9).
lndependent Laboratory Validation
MatrÌxes
Tlre matrixes lòr analr.sis rvere rice I'lour. gluten-fiee tl'ead.
Table 15, Data summary of gluten-free and spiked cooked
hamburger
Spike levels. ppm 0 40 20 10
Mean, ppm 0.25
l\ilean recovery, 70 NA'
Repeatability SD 0.29
Repeatability RSD, % NA
No. of replicates w¡th
acceptablerecoveryu r\^
LOD. ppm 1.21
LOQ, ppm 3.15
Mean RSD, % 17.96
Mean recovery, % 105.79
6.90 10.17 20.68
138.00 101 .65 103.25
2.13 2.29 1,96
30.87 22.s2 9.48
32.09
80.25
2.88
8.97
11/20 20t20 20t20 ?0/20
" NA = Not appl¡cable.
b The actual percentages are presented ¡n Table 11
Mean, ppm
N,4ean recovery, 7o
KepcatäuIt(y ùu
Repeatability RSD, %
No. of repl¡cates with
acceptable recoveryo
LOD. ppm
LOQ. ppm
Mean RSD, %
0.04 7.64 10.70 20Á2 32.99
NA' l 51 .68 107 .11 1 02.39 82.99
o.i8 i.56 i.26 2.56 3.6i
NA 20.42 't1 .78 12.54 10.94
NA 10120 20120 20120 20t20
0.63
1.84
13.92 13.92
l\¡ean Recovery. % 110.ô5 1 10.65
' NA = Not applicable.
b The actual percentages are presented in Table 1 2.
gluterr-fiee rice cereal. and cooked harnburger. ( the
diflìcult1,in preparing lrornogeneous incurred and bulk spiked
samples. one rnatrix (gluten-lì'ee bread) s as selected fòr
incurred sample preparation. and the rentaining three tnatrixes
u'ere individr.rally spiked rvith a liquid suspension ol*,heat fìour
descril¡ed belou'. All samples \\/ere prepared as irrdicated in
Reference l¡,ÍaÍerial Use¿l in SÍandor¿l Preparation and Spiking
sections of this docr¡rnent.
All samples sere blind-coded and shipped under cold packs
overnight f'or analvsis by the indcpendent laborator¡' on thc
dav of arr'val. A cor.rculrent blind sample set \\'as allal),zed bv
Neogen in parallel. Levels and replicates u'ere modeled alìe'r
hannonized guidelines I'or allergen ELISA validation. Sarnples
for spiking u,ere ground in a household blender to a lìne palticle
size and stored at -20oL-- au'aiting stud¡,, All samplcs anal_r'zed
as described in Ånal¡ sis section.
Five replicates of each level/uratrix combinatiou rrcre
randomll'coded and sent overnight to the indeper-rdent laborator¡,
packed on ice packs and analvzed the da-v the1,-arrired. Irive
leplicates x ûr'e levels resr¡lted in 25 test poltions per nratri.x.
One rratrix \\,as slìipped each da1, f'or 4 consecutive ilays: each
exlraction rvas perfòrnred directll,out ofthe tube provided.
AII data above 0.0 ppnì \\'ere reporled 1òr the purposes of'the
validation stud¡'. DLre to the Neogen calculation algorithrn. it is
not possible to produce negative (less than 0 ppnr) r'esults. All
100 extractions ricre anal),zcd ín duplicale l-or a total of'200 data
pointsl a corresponding set of200 data points was gÈner¿ìted bv
Neogen on the sanre sarnples. \\/hile duplicate sanrple anal¡,sis
is not a requilement olthe nlethod. it rvas requested in this case
to iucrease the number of'data points generated f-or stalistical
âltal¡'5i 5.
Data Analysis
All results u.ere tabulated ancl recovcries u'crc- detcrrni¡led.
conrparing to target lcvels to ensure that all resr¡lts shoscd alr
acceptable reco\¡er)'. rangin_e fronl 50 to 150% per J. .'1O,1C
-1n1. (6) Validalion Procedures fol Quantitative Irood Allersen
Ill.,lS¡\ ì\'Jethods: Conrnrurritv Ciuidance and lle st Placticcs.
LOD rvas calculated f'or each rnalrix using AOACIISO 5725