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Bidlack et al.:

J

ournal of

AOAC I

nternational

V

ol.

98, N

o.

5, 2015 

1389

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.12-191

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