FLOW-INJECTION SORBENT EXTRACTION WITH DIALKYLDITHIOPHOSPHATES AS CHELATING AGENT FOR THE DETERMINATION OF ZINC BY FLAME ATOMIC-ABSORPTION SPECTROMETRY
Rl. Ma et al., FLOW-INJECTION SORBENT EXTRACTION WITH DIALKYLDITHIOPHOSPHATES AS CHELATING AGENT FOR THE DETERMINATION OF ZINC BY FLAME ATOMIC-ABSORPTION SPECTROMETRY, Analytica chimica acta, 309(1-3), 1995, pp. 395-403
Dialkyldithiophosphates, (RO)(2)P(SS-, were used as the complexing age
nt for flow injection on-line sorbent extraction for the determination
of zinc by name atomic absorption spectrometry. The extractability,wi
th diethyl-, di-n-propyl-, di-2-propyl-, di-n-butyl-, di-isobutyl-, di
-sec.-butyl-, di-n-pentyl- and di-n-hexyldithiophosphates was compared
in respect of the effects of pH, alkyl group, masking agent and reage
nt concentration. Di-sec-butyldithiophosphate (0.5%, m/v) at pH 3 with
0.1 M citrate as a masking agent for iron, was used for the determina
tion of zinc in a number of certified biological and environmental ref
erence materials from the Community Bureau of Reference (BCR). All ana
lytical results were in good agreement with the certified values. The
detection limit (3 sigma) of peak height measurement, using a flow spo
iler in the spray chamber, was 0.5 mu g l(-1) with an enhancement fact
or of 35 for a 20-s sample loading at 8.7 ml min(-1).