Determination of trace aluminum in indirect air cooling unit circulating water by graphite furnace atomic absorption spectrophotometry

Abstract

Trace aluminum in SCAL type indirect air cooling unit circulating water was determined by graphite furnace atomic absorption spectrophotometry, the experimental conditions were optimized from the aspects of the working parameters of graphite furnace, matrix modifier, reagent blank, and water sample pretreatment methods. The experimental results showed that the linear correlation coefficient of calibration curve with aluminum ion standard solution concentration in the range of 0-20 μg/L could reach 0.999 8, the relative standard deviation was less than 10%, and the detection limit was 0.5 μg/L, when the graphite furnace ashing temperature and atomization temperature were 700 ℃ and 2 700 ℃, respectively, and there was no matrix modifier. The water samples were acidified for 1 hour and then directly determined. The measured values were compared with the standard heating digestion method. The deviation was within the range of 5.0%, and the blank value was less than 0.5 μg/L, which effectively solved the problem of the high blank value of the heating digestion method, and improved the accuracy of the determination of trace aluminum less than 10 μg/L in the circulating water of indirect air cooling unit.

Keywords

• graphite furnace atomic absorption spectrophotometry
• indirect air cooling unit circulating water
• trace aluminum
• matrix modifier
• blank value
• water sample pretreatment