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ournal of
AOAC I
nternational
V
ol.
98, N
o.
5, 2015
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areas of the same standards injected before and after a set of
samples have changed by more than 7%, the system was not
equilibrated and the data are not acceptable.
(c)
Calculation of
trans
vitamin K
1
standard concentration:
T
A
A A
(
)
2
1 2
= +
where T is the
trans
vitamin K
1
fraction, A
1
is the
cis
vitamin K
1
peak area, andA
2
is
trans
vitaminK
1
peak area. The
trans
vitamin
K
1
fraction is calculated for all standards, and the calculated
trans
vitamin K
1
fraction for all standards is averaged together
(T
a
) and used to calculate the
trans
vitamin K
1
concentration of
all standards.
(d)
Trans
vitamin K
1
standard concentration:
C C T
ST
S a
= ×
where C
ST
is the concentration of
trans
vitamin K
1
in the
working standard C
S
in µg/L and C
s
is the working standard
concentration in µg/L.
(e)
Preparation of standard curves
.—For each working
standard concentration, average the peak areas from each
two consecutive sets of standards. Prepare a standard curve
by performing a linear least-squares regression on
trans
concentration versus averaged peak areas. A standard curve
must have an r
2
of 0.999 or better to be acceptable.
(f)
Calculation of
trans
vitamin K
1
in a sample:
= × ×
×
10.0
C
C
R
S P
p
c
where C
p
is the concentration of
trans
vitamin K
1
in µg/kg, C
c
is the concentration of
trans
vitamin K
1
in the injected sample
determined from the standard curve in µg/L, 10.0 is the dilution
volume of the sample in mL, R is the final dilution weight of a
product reconstitution in g (if necessary), S is the sample size
in g, and P is the weight of product that is reconstituted in g (if
necessary).
G. Validation Data
See
Tables 2 and 3.
Conclusions
AOAC
2015.09
met all of the SPIFAN SMPR and was
approved for First Action status by an AOAC expert review
panel at the AOAC Mid-Year Meeting in March 2015.
References
(1) Ball, G.F.M. (1988)
Fat-Soluble Vitamin Assays in Food
Analysis A Comprehensive Review
, Elsevier Applied Science,
London, UK
(2) AOAC SMPR 2014.001
(2015) J. AOAC Int . 98 , 1036.http://
dx.doi.org/10.5740/jaoac.int.SMPR2014.001(3) AOAC
Official Method
992.27
(2012)
Official Methods of
Analysis of AOAC INTERNATIONAL
, 19th Ed., Rockville, MD
(4) AOAC
Official Method
999.15
(2012)
Official Methods of
Analysis of AOAC INTERNATIONAL
, 19th Ed., Rockville, MD
(5) Schimpf, K.J., Thompson, L.B., & Schmitz, D.J.
(2010) J. AOAC Int . 93 , 650–662(6) Delmonte, P., Barrientos, S., & Rader, J.I.
(2013) J. AOAC Int . 96 , 91–101. http://dx.doi.org/10.5740/jaoacint.12-191Candidates for 2016 Method of the Year
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