Sh. Yao et al., DETERMINATION OF AMMONIA AND ALIPHATIC-AMINES IN FOOD BY ION CHROMATOGRAPHY WITH DOUBLE-CELL BULK ACOUSTIC-WAVE DETECTION, Journal of AOAC International, 81(5), 1998, pp. 1099-1103
An ion chromatographic (IC) method with double-cell bulk acoustic wave
(DCBAW) detection is described for determination of ammonia and low-m
olecular-mass aliphatic amines in food. A 9 MHz AT-cut quartz crystal
is used as the resonator. This detection technique provides high sensi
tivity, good reproducibility, and wide work region. Its sensitivity is
independent of background conductivity of the mobile phase in the ran
ge 10-2700 mu S. Detection limits (peak = 3 delta) for NH4+, CH3NH3+,
(CH3)(2)NH2+, and (CH3)(3)NH+ were 0.02, 0.05, 0.13, and 0.6 mu g/mL,
respectively, Relative standard deviations for NH4+ CH3NH3+, (CH3)(2)N
H2+, and (CH3)(3)NH+ were 0.7, 1.0, 0.8, and 1.2%, respectively. For I
C analysis, the analytical column is a Shim-pack IC-C1 column and the
mobile phase is 2.0 mmol/L nitric acid solution at a flow rate of 1,5
mL/min. Detection with DCBAW was compared with series bulk acoustic wa
ve and conventional conductivity. The method was applied to analyses o
f egg, fish, and cured meat.