Comparison of the Strychnidine and Hydrazine Methods for the Estimation of Nitrate in Seawater

Abstract

It has been shown that the hydrazine reduction method is superior to the strychnidine method for the estimation of nitrate in seawater samples containing less than 10 µg-atom nitrate N per litre. On samples containing higher amounts of nitrate than this both methods give similar results. Samples should be filtered and stored in chemically clean glass bottles for analysis by the hydrazine method, but may be kept in seasoned polyethylene vessels and preserved by the addition of mercuric chloride, for analysis by the strychnidine method.