M. Galtayries et al., Determination of methyl anthranilate in food samples by coupling stopped-flow mixing technique and time-resolved luminescence detection, LUMINESCENC, 15(6), 2000, pp. 363-369
A sensitive and fast approach for the determination of methyl anthranilate
in grape must and honey samples, using time-resolved luminescence measureme
nts, has been reported for the first time. The method involves the alkaline
hydrolysis of the ester to anthranilic acid and the formation of a chelate
with terbium(III) and tri-n-octylphosphine oxide in presence of Triton X-1
00. Kinetic and equilibrium measurements were obtained in 0.1 and 15 s, res
pectively, by using a stopped-how mixing technique. The dynamic ranges of t
he calibration graphs of the kinetic and equilibrium methods were 21.9 nmol
/L-29.2 mu mol/L and 19.7 nmol/L-21.9 mu mol/L, respectively, and the detec
tion limits were 7.3 and 6.6 nmol/L, respectively. The precision, expressed
as relative standard deviation, was less than 3%. Although both-kinetic an
d equilibrium methods exhibited very similar analytical features, only the
better selectivity of the former allowed the content of methyl anthranilate
to be determined in the samples, as the initial rate measurements avoided
the negative effect that the sample matrix caused in the equilibrium measur
ements. The analytical recoveries obtained by applying the kinetic method t
o the analysis of grape must and flower honey samples were in the range 92.
5-105.0%. Copyright (C) 2000 John Wiley & Sons, Ltd.