1. Preparation of Mobile Phase
a) Dissolve 1.64 g of anhydrous sodium acetate in 2 L of water (Soln. A)
b) Transfer 1910 mL of Soln. A to a 2 L volumetric flask, add 50 mL of acetonitrile and 40 mL of tetrahydrofuran and mix.
c) Adjust to pH 4.5, mix, filter and degas.
2. Preparation of Test Solutions
a) Test Solution 1: Transfer 40 mg of Caffeine Sample 1 to a 200 mL volumetric flask and dissolve in about 50 mL of mobile phase (sonicate if necessary), dilute to volume with mobile phase and mix.
b) Test Solution 2: Transfer 40 mg of Caffeine Sample 2 to a 200 mL volumetric flask and dissolve in about 50 mL of mobile phase (sonicate if necessary), dilute to volume with mobile phase and mix.
3. Perform the liquid chromatography according to the USP Caffeine Monograph for Related Compounds, or the company′s SOP for HPLC analysis of Caffeine impurity analysis.
4. Identify which Caffeine Sample passes according to the Caffeine Monograph (NMT 0.1% Impurities).
Reported Data: Identify which Caffeine Sample is passing (Data = 1 or 2)
Storage and Stability
Please refer to sample label for expiration date, specific storage temperature, and specific storage conditions.