AOACSPIFANMethods-2017Awards

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G ill et al .: J ournal of AOAC I nternational V ol . 99, N o . 5, 2016  1325

Table 2016.05E. Compound parameters (vitamin D 2

instrument method only)

ion a

DP, V b

EP, V c

CE, V d

CXP, V e

Vitamin D 2

Precursor ion, m/z Product ion, m/z

Dwell time, ms

Analyte quantifier Analyte qualifier

572.2 572.2 578.2 578.2

298.0 280.0 298.0 280.0

81 81 81 81

10 10 10 10

23 39 23 39

22 16 22 16

120

80

Internal standard quantifier Internal standard qualifier a  The analyte is the vitamin D 2 b  DP=Declustering potential. c  EP=Entrance potential. d  CE=Collision energy. e  CXP=Collision cell exit potential.

120

80

–PTAD adduct, and the internal standard ion is the d6 -vitamin D 2

–PTAD adduct.

Table 2016.05F. Compound parameters (vitamin D 3

instrument method only)

ion a

DP, V b

EP, V c

CE, V d

CXP, V e

Vitamin D 3

Precursor ion, m/z Product ion, m/z

Dwell time, ms

Analyte quantifier Analyte qualifier

560.2 560.2 566.2 566.2

298.0 280.0 298.0 280.0

151 151 151 151

10 10 10 10

21 37 21 37

18 18 18 18

120

80

Internal standard quantifier Internal standard qualifier a  The analyte is the vitamin D 3 b  DP=Declustering potential. c  EP=Entrance potential. d  CE=Collision energy. e  CXP=Collision cell exit potential.

120

80

–PTAD adduct, and the internal standard ion is the d6 -vitamin D 3

–PTAD adduct.

NLWS Dconcn

where NLWS D2concn

is the concentration of vitamin D 2

in the

is the concentration of vitamin D 2

or vitamin D 3

in

working standard (ng/mL), NLD 2

PS D2concn

is the concentration

the working standard (ng/mL). (j)  Concentrations of stable isotope-labeled d6-vitamin D 2 and d6-vitamin D 3 in the calibration standards, CS1–CS5. — − = × CS1 5 SILIS 0.25 25 Dconcn Dconcn

of vitamin D 2

in the purity standard (μg/mL), and 1000 is the

concentration conversion factor (μg/mL to ng/mL). (h)  Concentration of nonlabeled vitamin D 3

in the working

standard NLWS. —

× × 1.0 10

=

NLWS

NLD PS

1000

D3concn

3 D3concn

where CS1 through CS5 Dconcn

are the concentrations of in calibration standards (ng/mL),

or d6 -vitaminD 3

d6 -vitaminD 2 and SILIS Dconcn d6 -vitamin D 3

where NLWS D3concn

is the concentration of vitamin D 3 in

is the concentration of d6 -vitamin D 2 or

working standard (ng/mL), NLD 3

PS D3concn

is the concentration

in internal standard (ng/mL). (k)  Mass of powder in slurried sample. —

of vitamin D 3

in purity standard (μg/mL), and 1000 is the

concentration conversion factor (μg/mL to ng/mL). (i)  Concentrations of vitaminD 2 and vitaminD 3

+ D (D W ) mass mass mass

in calibration

=

×

S

A

mass

mass

standards, CS1–CS5. —

0.01 25

where S mass is the mass of the sample (g), D mass of the dry powder used to make the slurry (g), W mass of the water used to make the slurry (g), and A mass is the mass of the aliquot of slurried sample used in the analysis (g). (l)  Determine the linear regression curves (vitamin D 2 and vitamin D 3 ) y = m·x + c (using the least-squares method) for the ratio of peak areas (nonlabeled vitamin D/stable isotope-labeled d6 -vitamin D) versus the ratio of concentrations (nonlabeled vitamin D/stable isotope-labeled d6 -vitamin D) for the five calibration standards, with the y -intercept forced through zero. (m)  The concentration (w/w) of vitamin D 2 or vitamin D 3 in the dry powders is calculated as is the mass is the mass

=

×

CS1

NLWS

Dconcn

Dconcn

0.05 25 0.25 25

=

×

CS2

NLWS

Dconcn

Dconcn

=

×

CS3

NLWS

Dconcn

Dconcn

0.5 25

=

×

CS4

NLWS

Dconcn

Dconcn

1.25 25

=

×

CS5

NLWS

Dconcn

Dconcn

SILIS S

PA PA

SILIS

100 1000

alqt

where CS1 through CS5 Dconcn

are the concentrations of vitamin

NLD SILD

Dconcn

=

×

×

×

Result D

L

D 2

or vitamin D 3

in the calibration standards (ng/mL), and

mass