Are nitrate and nitrite test results affected by exposure to sunlight?
Sunlight exposure during nitrate testing
Sunlight has been shown to significantly increase nitrate results if samples are left in the sun for the 15 minute reaction period. The same effect has been reproduced using a UV lamp. Tests done in normal office/lab lighting (typically fluorescent), should display accurate results. Since many of our nitrite tests use the same indicator as the nitrate reduction methods, the UV/sunlight exposure concern is the same when running nitrite tests.