Determination of Chloride by Flame molecular Absorption Spectrometry with Continuum Source and Self-Reversal Background Correction

Abstract

The use of continuum source and self-reversal background correction were investigated for flame molecular absorption spectrometry (MAS). Chloride was determined by MAS using the aluminum monochloride molecule in a conventional flame atomic absorption spectrometer. Absorbance of this molecule was monitored in a lean nitrous oxide/acetylene flame at 261.4 nm using a lead hollow cathode lamp as the excitation source. Characteristic masses of 210, 260, and 820 mg/L were observed for no background correction, continuum source correction, and self-reversal correction, respectively. The ability of the techniques to correct for interferences caused by high concentrations of fluoride and sodium was investigated. The self-reversal technique was shown to remove interferences at concentration levels up to 10,000 mg/L. Chloride was determined in chloroacetic acid using calibration with chloride standards; continuum source correction had the best recovery value. These results suggest that both correction methods should be investigated for practical applications of flame MAS to obtain optimum analytical performance.

Key Words:

• chloride determination
• nitrous oxide/acetylene flame
• continuum source background correction
• self-reversal background correction