Determination of sulphate for measuring magnesium sulphate in pharmaceuticals by flow analysis-fourier transforms infrared spectroscopy

The viability of employing flow analysis coupled to Fourier transform infrared spectroscopy (FA-FTIR) as a useful tool for quantitative measuring of magnesium sulphate in pharmaceuticals was explored, developed and validated. The method was based on mid-IR transmittance measurements of the peak-area belonging to the sulphate band around 1110 cm–1 and the use of an external calibration curve. Dynamic range was established over a concentration range from 1 to 50 mg.ml–1 , with a limit of detection (3σ) of 0.26 mg.ml–1 The analytical frequency was 12 h–1 with a precision close to the unit (% RSD). The . analytical results obtained in commercial formulations by applying the proposed FA-FTIR method were in strong agreement with labelled values and those obtained by a reference titration method at 95% confidence level. Among various advantages offered by the proposed method over conventional ones, simple strategy and clean analytical chemistry must been highlighted. Colegio de Farmacéuticos de la Provincia de Buenos Aires