Slurry analysis by multichannel arc/spark emission spectrometry using a monosegmented system: Determination of aluminium in sediments

This work proposes a new approach for sediment analysis in which the sample is introduced as a slurry in an arc/spark emission spectrometer using a mo nosegmented system. The spectrometer has been modified to employ a 1024 pho todiode-array detector capable of collecting intensities in a 18.7 nm wide wavelength window. Sediment slurries were prepared with 8.5-50 mg of the sa mples, grounded to a particle size less than 38 mu m, transferred to a 50 m L volumetric flask in which 1 mL of conc.HNO3 and 300 mu L of 10% m/v La (a s La2O3; used as internal standard) were added. The slurry (25 mu L) was in troduced into the monosegmented system and transported by an air stream to a graphite rod in the existing arc/spark source. About 40 samples can be an alyzed per hour. Results for reference materials show acceptable accuracy a nd precision for the proposed method. (C) 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:46-52, 2000.