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Abbott Nutrition Division
Simultaneous Determination of Total Vitamin B
6,
B
2,
B
3
and B
1
in Infant
Formula Products by LC-MS/MS Using Enzymatic Digestion
Example:
The Pyridoxine standard weight is 15.11 mg is 100% pure. The Pyridoxine stock
concentration, [PN]
S
is 124.31
m
g/mL and is calculated as follows:
[ ]
mL g
mg
PN
S
/
31. 124
10 1 8227 .0
11.15
m
= ××
×
=
b)
Thiamine Hydrochloride:
[ ]
10
100
000 ,1 1
×× ×
=
××× ×
=
• •
• •
PM W
mL
P M W THI
HCl
Cl
THI
HCl
Cl
THI
VSSM
Example:
The Thiamine Hydrochloride standard weight is 10.65 mg is 99.8% pure and the
standard is found to have 4.6% moisture. The Thiamine stock concentration,
[THI]
S
,
is 69.51
m
g/mL and is calculated as follows:
954 .0
100
4.95
100
)6.4(
100
= =
−
=
M
[ ]
mL g
mg
THI
S
/
51.69 10 998 .0 954 .0
65.10
m
= × × ×
=
c)
Riboflavin
[ ]
10
100
000 ,1 11
×× =
××××
=
P W
mL
P
W RIB
RIB
RIB
VSSM
Example:
Riboflavin standard weight is 7.12mg and is 100% pure. The Riboflavin
concentration in the Vitamin Standard Stock Mixture, [RIB]
VSSM
is 71.2
m
g/mL
and is calculated as follows:
[ ]
mL g
mg
RIB
VSSM
/ 2.71 10 00.1
12.7
m
= × ×
=
4.
Calculation of the Intermediate Working Standard Solution (IWSS)
S
S
IWSS
Vit
mL
µL
Volume
StockStd
L
mL
g
ng
Vit
(mL)
Volume
IWSS
Volume(µL)
Standard
Stoc
Vit
] [
10
) (
1000
1
1000
] [
] [
×
=
×
× ×
=
m
m
where:
[Vit]
IWSS
: Concentration of the vitamin of interest in the Intermediate Working Standard
Solution, in ng/mL
[Vit]
S
: Vitamin Stock Standard Concentration, in
m
g/mL
39
BVit-02
FOR ERP USE ONLY
DO NOT DISTRIBUTE