In order to optimize the LC separation of aceclofenac and diacerein, initially, the retention behavior of both the components was studied in the pH range of 2.5-6.8 2.5-6.8obile phases of busing (pH 2.5-6.8) and acetonitrile, mobileol as organic modifier.
Protein binding was evaluated during an association phase (0 300 sec), which was followed by a dissociation phase (injection of buffer only, 300 3700 sec).
The mobile phase consisted of buffer A (0.1 % TFA in water) and buffer B (Methanol).
Finally the mobile phase consisting of buffer (0.05 M sodium phosphate buffer containing 0.1 gm% 1-octane sulphonic acid and 1% (v/v) triethylamine adjusted to pH 2.7): methanol in a ratio of (60 40, v/v) at a flow rate of 1.5 ml/min was found appropriate allowing adequate separation of the five compounds; FEX and its four related impurities.
The mobile phase consisted of buffer A (10 mM ammonium acetate, pH 4.3) and buffer B (methanol).
Mobile phase consists of buffer A (5 mM KH2PO4, 25% acetonitrile, pH 2.8) and buffer B (buffer A plus 350 mM KCl).
The mobile phase comprised of buffer A (H2O containing 20% CH3CN and 0.1% trifluoroacetic acid (TFA)) and buffer B (CH3CN containing 0.1% TFA).
The gradient mobile phase consisted of Buffer A (0.1 M Triethylammonium Acetate pH 7.0) and Buffer B (0.1 M Triethylammonium Acetate pH 7.0) and 25% Acetonitrile.
The samples were assayed using a validated high performance liquid chromatography method (HPLC; Waters corporation, Milford, MA, USA) The analytical column was C18 Gemini (Phenomenex NS655712-5) with a 5-μm particle size and 150 × 4.6 mm internal diameter, using a mobile phase of phosphate buffer and acetonitrile.
Knowledge gaps relative to climate and water quality regulation services were identified for the establishment phase of bioenergy buffers (0-3y).
