Kjeldahl digestion (Plantae)

Knowledge graph centered on Kjeldahl digestion (Plantae) with 30 nodes and 107 connections. Top connected: Asteraceae, Erigeron, Helianthella, herbaceous plants, Helianthella quinquenervis.

Method synopsis

Standard Kjeldahl digestion method for determining total nitrogen and phosphorus content in plant tissues through acid digestion followed by colorimetric analysis.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Aboveground resilience to species loss but belowground resistance to nitrogen addition in a montane plant community (2017), Journal of Plant Ecology. Implementations in other papers (listed below) may differ.

1. Process samples for chemical analysis
   Ground dried tissue samples (leaf and root) with mortar and pestle if available, weighing at least 20 mg or up to 75 mg if available. Folded ground sample into adhesive-free cigarette paper. Digested sample for 5 h at 550°C in 1 ml H₂SO₄ in Kjeldatherm digestion block (Gerhardt, Königswinter, Germany), including blank and apple leaf standard samples. After cooling, added 45 ml deionized water, used SmartChem 200 discrete analyser (Unity Scientific, Brookfield, CT, USA) to measure total Kjeldahl N and P
   Quantities: 20-75 mg tissue samples, 1 ml H₂SO₄, 45 ml deionized water per sampleDuration: 5 hours digestion at 550°CConditions: Laboratory conditions at 550°C
   Equipment: mortar and pestle, analytical balance, adhesive-free cigarette paper, Kjeldatherm digestion block, Gerhardt, SmartChem 200 discrete analyser, Unity Scientific

Typical Equipment

• Kjeldatherm digestion block
• SmartChem 200 discrete analyser

Output Measurements

• tissue nitrogen content
• tissue phosphorus content
• leaf N:P ratio
• root N:P ratio

Papers Using This Protocol (1)

Species Studied With This Protocol