Nitrates can stimulate cancer, mainly related to the digestive system. These unhealthy compounds accumulate in the body, so there are annual rates of human nitrate intake, which leads to the need to measure nitrates in vegetables.
You can analyze the amount of nitrates by the following ways: electrical conductivity and nitrate meters, photometry, ionometry, ELISA. Let’s briefly consider each of the methods.
First method is performed on the basis of measuring the conductivity of alternating high-frequency current in the measured product. The electrical conductivity of a substance is significantly affected by the salts present in it. That is, such a method can approximately determin the total amount of salts, but to determine the concentration of nitrates — is impossible, because products contain different salts.
Photometry measure illuminance, light intensity, luminous flux, the transmittance and optical density of transparent liquid solutions and transparent solid samples, as well as to measure the rate of change of the optical density of a substance and to determine the concentration of a substance in solutions. The possibility of carrying out an express photometry method for determining the content of sorbic and benzoic acids in their joint presence on ultraviolet spectra allows to speed up the analysis time and simplify sample preparation.
Ionometric analysis is based on determining the concentration of the ion by the magnitude of the electromotive force (EMF) of the electrochemical circuit. The method of potentiometry is generally inferior to photometry in terms of versatility, selectivity and sensitivity. This, in particular, explains the fact that certified photometric methods of analysis are disproportionately more than ionometric methods.
Enzyme-linked immunosorbent assay (ELISA) is a method of target antigen (or antibody) capture in samples using a specific antibody (or antigen), and of target molecule detection/quantitation using an enzyme reaction with its substrate. This option is eliminated due to incomplete automation, namely the need for a laboratory assistant.
After analyzing the available technologies, we can conclude that the closest expected results we will get using photometry technology.
