Ammonium fluoride as a novel chemical modifier for the elimination of magnesium chloride interference on the determination of lead by graphite furnace atomic absorption spectrometry.
Ammonium fluoride was found to be very efficient modifier for the elimination of MgCl(2) interference on Pb determination. Ammonium fluoride probably converts strongly interfering volatile MgCl(2) to less volatile MgF(2) matrix that makes possible the release of Pb analyte at lower temperature, before the matrix starts to vaporize. It was observed likewise that NH(4)F removes the interferences mentioned, i.e. caused by MgCl(2) presence, much more effectively as compared with some modifiers, before now recommended for this purpose. The application of this modifier to the determination of Pb in 2% (m/v) MgCl(2) has ensured the characteristic mass and LOD value in the original sample of 12pg and 60ngg(-1), respectively (10mul aliquots of sample). Applying the modifier to standards and samples enables the use of matrix-free standard solutions for attaining accurate analysis as verified by recovery studies.
Husáková
Lenka
L
Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, nám. Cs. legií 565, Pardubice CZ-532 10, Czech Republic.
Srámková
Jitka
J
Cernohorský
Tomás
T
Barinová
Martina
M