Flow-injection electrochemical determination of citric acid using a cobalt(II)-phthalocyanine modified carbon paste electrode

► An extremely simple and rapid, highly pursued, method for citric acid is proposed. ► A renewing easy building eco-friendly (mercury-free) voltammetric sensor is used. ► A lowest concentration range (μM) never attained with voltammetric methods. ► A practical strategy to eliminate the main interference species is pointed out.