【求助】急需美国药典USP30氯化物Chloride(Reagent test)和硝酸盐Nitratr(Reagent test)的测定方法

Chloride: Dissolve the specified quantity of substance under test in 30-40mL H2O, or where the substance under solution, add H2O to make a total volume of 30-40 ml. If necessary, neutralize the solution with nitric acid to litmus. Add 1 ml each of nitric acid and of silver nitrate TS and sufficient water to make 50 ml. Mix, and allow to stand 5 min protected from sunlight. Unless otherwise specific on the monograph, compare the turbidity, if any, with the produced in a solution containing the volume of 0.020 N hydrochloric acid specified in the monograph.

Nitrate in reagents:
A: Standard Nitrate solution: dissolve 163 mg of potassium nitrate in 100 mL H2O, pipet 10 ml from above solution in 1000 mL to obtain 0.01 mg of NO3 per mL.
B: Brucine Sulfate Solution: Dissolve 600 mg of brucine sulfate in 600-mL of nitrate-free, dilute sulfuric acids ( 2 in 3), cool to room temp, bring to 1000 ml volume with aicds.
C: sample solution: to the weigh of sample specified in individual reagen specification, dissolved in a designated volume of H2O, add Brucine Sulfate Solution to 50 ml.
D: Control Solution: to a volume of Brucine Sulfate Solution equivalent to the weight of Notrate ( NO3) specified in the individual reagent specification, add the weight of sample as “C” and add Brucine Sulfate Solution to 50 ml.

D Blank Solution: 50 ml of add Brucine Sulfate Solution to 50 ml.
Procedure: Heat sample solution, control solution, and blank solution in boiling water bath 10 min, cool to room temp.
Perforce instrument ZERO absorbance @ 410 nm, determine the absorbance of sample solution, note the reading results. Determine the absorbance of control solution: the absorbance value reading for sample should not larger than that for the control solution.