Total nitrogen determination for plant material containing nitrate

✍ Scribed by E.F. Eastin

• Book ID: 102629910
• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 206 KB
• Volume: 85
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(78)90259-2

✦ Synopsis

A nonfoaming method for semimicro Kjeldahl determination of total nitrogen in plant samples containing appreciable amounts of nitrate was developed for use with a digestion block utilizing test tubes for digestion flasks. The sample (30 to 200 mg) is treated with 5 ml of a sulfuric acid:salicylic acid (3O:l v/w) mixture at room temperature for 1 hr. Catalyst [K,SO,:CuSeO,.ZH,O:pumice 970:19:11 w/w/w)] is added and the mixture is digested at 360 to 380°C for 1 hr after the mixture clears. Ammonium in the digest is determined by a suitable method. This semimicro Kjeldahl procedure results in a 95% or better recovery of nitrate, either from KN03 or from KN03 added to plant material.