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Reagents:
Carrier:
DI Water
Reagent 1:
Hydrochloric acid
For free sulfite
use 4M HCl. For total sulfite use 6 M
HCl.
Reagent 2: DTNB Solution
0.06 g DTNB (5,5'-Dithio-Bis
(2-Nitrobenzoic Acid))
10mL isopropanol
1 L TOTAL: Balance with PBS buffer
solution (Phosphate buffered Saline
Sigma: P-3813)
Dissolve 0.06g of DTNB in the 10 mL of
isopropanol. Prepare the PBS solution by
adding one packet of PBS (Phosphate
buffered Saline Sigma: P-3813) to 1 L of
H2O, and mix well. Add ~900 mL of PBS
buffer solution to a 1 L volumetric
flask. Add the dissolved DTNB solution
to the flask. Fill flask to mark with
PBS buffer solution, mix well.
FOR TOTAL SULFITE:
The samples must be pretreated with
sodium hydroxide.
0.7g Sodium Hydroxide
10 mL of Sample
Dissolve the sodium hydroxide in the
sample, and allow to sit for 5 minutes.
Standards:
1000ppm Sulifte Standard:
0.7415g Sodium Meta-bisulfite
500mL TOTAL: Balanced with Stabilizing
buffer
Stabilizing buffer:
10.7g Sodium Phosphate, Dibasic
3.6g D-Mannitol
300mL Ethyl Alcohol
2 L TOTAL: Balanced with Deionized Water
Dissolve 10.7 g of sodium phosphate,
dibasic and 3.6 g of D-Mannitol in about
500 mL of deionized water contained in a
2 liter flask. Add 300 mL of ethyl
alcohol. Dilute to the mark with
deionized water and mix well. Prepare as
needed. Cover when not in use.
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