as an internal standard. Öztekin et al. (2002) determined
the nitrite and nitrate in meat products using a CE method
based on the separation of the two anions in a capillary
coated with polyethyleneimine, which allowed the reversal
of the electroosmotic flow. Solid samples were blended
for 2 min with deionized water and then the suspension
was incubated in a warm water bath and filtered. Good
reproducibility and recovery were obtained using thiocyanate
as the internal standard. Shiddiky et al. (2009)
measured nitrite in ham and sausage using microchip CE
with extraction by either sonication or microwave irradiation.
The technique provided an analysis time of 4 min,
together with good sensitivity. More recently, these
authors proposed the application of an isotachophoretic
CE method to the simultaneous determination of nitrate
and nitrite in meat products. Samples were minced and
homogenized using a plate with 3-mm diameter holes.
The meat product samples were then extracted with
redistilled water using an orbital shaker (Jastrzebska
2010).
In this work, an alternative method for the analysis of
nitrite and nitrate has been developed and applied to meat
samples. The method is based on free solution CE with
direct UV detection (at 210 nm). Two different sample
preparation methodologies (manual and mechanical) were
investigated; the optimized technique was compared with
the standard methodology normally adopted in Brazil using
analyses of real samples.