[Simultaneous determination of nine typical anions in fire explosive residues by ion chromatography]

A novel method was developed for the simultaneous determination of nine typical anions (Cl^-, NO₂^-, ClO₃^-, NO₃^-, CO₃^2-, SO₄^2-, S₂O₃^2-, SCN^-and ClO₄^-) in explosive residues by ion chromatography (IC). A high capacity anion-exchange IonPac AS20 column (250 mm×4 mm) was used for the separation of the nine anions with gradient elution of KOH. The injection volume was 20 μL, the column temperature was 40℃, and the flow rate was 1.20 mL/min. Inhibitory conductivity detections were adopted in the determinations. Good linearities were found for all the nine anions in their respective ranges. The correlation coefficients were greater than 0.999. The method was applied to the determination of the inorganic ions in explosive residues. The average recovery of the nine ions ranged from 92.5% to 101.3%. The relative standard deviations of the nine anions ranged from 1.86% to 2.79% (n=6). The method is simple, quick, selective and sensitive and can meet the requirement of the analysis.