A semiautomatic, wet‐oxidation method for the determination of particulate organic nitrogen collected on filters

摘要: A wet-oxidation method with peroxydisulfate digestion at 120°C is presented for routine analysis of particulate organic N (PON) collected on glass-fiber filters. The technique was adapted from a previous procedure oxidizing total in seawater to NO3− . Comparisons PON determinations by dry combustion 800°C indicated high efficiency the procedure, giving 100% recovery cell cultures and natural samples. Neutralizing buffer pH adjustment proved be necessary but were simplified using Technicon AutoAnalyzer system. applied follow NO3−assimilation phytoplankton revealed excretion compounds cells end exponential phase growth. sensitivity makes it possible filter smaller quantities than needed (by 1–2 orders magnitude) can easily shipboard use.