The nitrate content was determined by means of its
reduction to nitrite by vanadium trichloride and sub
sequent determination as nitrite; RNO2 was deter
mined as compounds acquiring properties of INCs in
the presence of ferrous iron and thiols. The method
has a sensitivity limit of 50 nM [6]. For comparison,
we used also classical methods of determining nitrite
and Snitrosothiols based on the Griess reaction [6].