Analysis of glipizide and pravastatin sodium drug molecules at trace level by using magnetic solid phase extraction...

An easy applicable and selective sample preparation technique has been developed for trace and simultaneously analysis of Glipizide (GLP) and Pravastatin (PST) molecules in biological matrices based on magnetic solid phase extraction (MSPE) and high-performance liquid chromatography (HPLC). A new magnetic adsorbent including Fe₃O₄@TEOS-Melamine has been synthetized and characterized for extraction studies. Experimental variables of MSPE were examined and optimized step by step such as pH, adsorption and desorption conditions, time effect, etc. Simultaneous HPLC analysis of GLP and PST molecules was performed by isocratic elution of a mixture of acetonitrile: phosphate buffer (pH:3.0, 0.02 M) (35:65) with flow rate 1.0 mL min^-1. Analytical signals obtained from DAD detector were recorder in 238 and 226 nm for PST and GLP, respectively. The limit of detections (LOD) for proposed method were 3.17 ng mL^-1 for PST and 3.03 ng mL^-1 for GLP molecules. Consequently, accuracy and precision of developed method were tested by means of recovery tests in synthetic urine and saliva samples. RSD % values were lower than 6.1 % and recovery values were in the range of 98.5-103.3 % for both molecules.