DETERMINATION OF BORON BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY - TESTING DIFFERENT MODIFIERS, ATOMIZATION SURFACES AND POTENTIAL INTERFERENTS

The determination of B by electrothermal atomic absorption spectrometry (ETAAS) was investigated. Calcium (as chloride and nitrate), Ni (as chloride and nitrate), Mg, Y and La (all as chloride) were tested as modifiers. Considering pyrolysis temperature and sensitivity, Ca, as chloride, showed the best performance. Mineral acids and common salts led to severe interference effects. A long tail in the absorption pulse was always observed and a blank had to be performed between consecutive measurements in order to avoid memory effects. Boron was successfully determined by ETAAS in two National Institute of Standards and Technology (NIST) standard reference material (SRM) digests NIST SRM 1570 Spinach Leaves and NIST SRM 1571 Orchard Leaves after a separation step, using the standard additions technique for calibration. Atomization from surfaces other than the pyrolytic graphite coated graphite tube wall did not lead to any improvement in the analytical performance.