Spectrophotometric determination of gallium in biological materials at nanogram levels with thiocarbohydrazone derivatives.
Two spectrophotometric methods for the determination of micrograms of gallium in biological materials are described. Proposed chromogenic reagents are 1-(phenyl-2-pyridyl)carbylidene-5-resorcylidenethiocarbohydrazo ne (PPRT) and 1-(phenyl-2-pyridyl)carbylidene-5-salicylidene thiocarbohydrazone (PPST), which form yellow 1:2 (gallium: reagent) complexes. Reactions develop at pH 4.5-6.0 in a 52% (v/v) DMF solution for PPST and at pH 4.0-7.5 in a 48% (v/v) ethanol solution for PPRT. Optimum conditions for reactions are discussed for molar absorptivity values of 59000 and 65000 l.mol-1.cm-1 for PPST and PPRT, respectively. Detection limits are 8 ng/ml for PPST and 5 ng/ml for PPRT, and the range of application is 20-800 ng/ml of gallium. Advantages of the methods include simplicity, high sensitivity and relative selectivity, allowing their application in the determination of gallium in spiked biological samples, using a previous extraction step in n-butyl acetate to avoid interference from Fe(III) and Cu(II).
Lucena
R B
RB
Department of Analytical Chemistry, Faculty of Chemistry, University of Seville, Spain.
Morales
E
E
Gomez-Ariza
J L
JL
D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D005708:Gallium / Q000032:analysis*; D006835:Hydrazones; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D010783:Photometry
D006835:Hydrazones; D007202:Indicators and Reagents; C088743:1-(phenyl-2-pyridyl)carbylidene-5-resorcylidenethiocarbohydrazone; C088744:1-(phenyl-2-pyridyl)carbylidene-5-salicylidenethiocarbohydrazone; D005708:Gallium