The in-line separation with an anion-exchange column
was effective to avoid the interference of common organic
and inorganic species on nitrate determination by direct measurements in ultraviolet. The same mini-column containing
ca.180 mg ion-exchange resin was employed for at least 500
measurements. The proposed procedure is a clean alternative
for nitrate determination in natural waters, because neither
toxic nor carcinogenic reagents are employed and the only
chemical product (perchloric acid) is employed in a minimum
amount.