Walidacja metody analitycznej do oznaczania azotanów (V) i (III) w żywności techniką wysokosprawnej chromatografii jonowej

A simple and selective method was validated for the determination of nitrates (V) and (III) by ion chromatography technique. Efficient ion separation was achieved on a column IonPacTM AG-9HC, (4 × 50 mm). A conductometric detector was used for the detection of the analyte. The mobile phase consisted of 9.0 mM sodium carbonate (Na2CO3) and was delivered in a isocratic mode at a flow rate of 1.0 ml·min-1 at 30 °C. The method was validated for linearity, selectivity, precision, limit of detection LOD, limit of quantitation LOQ and uncertainty. The method demonstrates good linearity, with r = 0.998. The uncertainty is 29.0% and 35.0% for nitrates (V) and (III), respectively. The limit of detection (LOD) values are 0.080 mg·dm-3 and 0.040 mg·dm-3 for nitrates (V) for nitrates (III), respectively. Limit of quantitation (LOQ) values are 0.240 mg·dm-3 and 0.120 mg·dm-3 for nitrates (V) and (III), respectively. The low limit of detection and limit of quantitation of nitrate and nitrite ions enables the detection and quantitation of these ions at low concentrations. This method is characterized by high selectivity.