Abstract
One milligram of powdered quartz sample was mixed with 1 mg of pulverized graphite to determine Mn and Cu by direct atomization-AAS in a miniature graphite cup placed in graphite crucible. Ten microliters of 0.2 ppm Ni solution was added to the sample powder as a matrix modifier. Optimum atomization conditions were as follows: drying at 80120°C (30 s), pyrolyzing at 1000°C (30 s) for Mn and 800°C (30 s) for Cu, and atomization at 2500°C (15 s) for Mn and 2600°C (15 s) for Cu. Calibration curves were made by using aqueous standard solutions. Results for Mn (0.0290.19 ppm) and Cu (0.0330.19 ppm) in synthetic quartz samples and rock crystals agreed well with values obtained by dissolved samples. Relative standard deviations (n = 5) were 2.8% for 0.037 ppm Mn and 1.9% for 0.099 ppm Cu.
