With deter
mination by these methods, nitroso compounds in
samples are represented mainly by nitrite (Table 3),
according to the enzyme sensor data, by RSNO, and
nitrites aren’t detected. With exogenous addition of
nitrite to the samples in doses of 1 and 2 µM, its con
tent in samples with determination by the enzyme sen
sor corresponded to the added amount, and with
determination by the classical method, the increase of
nitrite content was smaller (Table 3), which is probably
related to losses during purification [6]. This gives
grounds to consider the enzyme sensor data to be reli
able.