Central composite design (CCD) approach to develop HPLC method for caffeine: Application to coffee samples analysis of Jazan region, Saudi Arabia

Abstract

The goal of this study was to use High performance liquid chromatography (HPLC) with an Analytical Quality by Design (AQbD) approach to measure the amount of caffeine in selected coffee samples available in the local Jazan market in Saudi Arabia. The experiment was performed on a Waters HPLC system equipped with a Raptor C-18 column. To achieve chromatographic separation, a mobile phase of ammonium acetate buffer (10 mM; pH 4.0) and acetonitrile in a 90:10 v/v ratio was used with a flow rate of 1 mL/min for 5 minutes at 274 nm. AQbD was used to optimize chromatographic conditions using a central composite design (CCD). A factorial design of 23 (two factors and three responses) was used with Stat-Ease Inc.'s Design Expert 13.0.3.0 software, Minneapolis, USA. The HPLC method was validated using ICH and USP guidelines, and it met all acceptance criteria. In the dilution range of 2–28 µg/mL, the procedure was shown to be linear. The caffeine content of all five samples (5 g/100 mL) was found to be 20.59–25.38 mg, which was below the level of toxicological concern recommended by the USFDA.