Labconco™ Accessories for Labconco™ Kjeldahl Rapid Digester-25
Required for use with Labconco Rapid Digestors
DWK Life Sciences Wheaton™ One-Piece Scrubber Absorber Tube
Modified version of catalog number 180020 for arsine analysis
Parr™ General Purpose Acid Digestion Bombs
Acid digestion bomb for organic and inorganic analytical samples
Foss™ Digestion System: Digestion Tubes
Straight-sided tubes recommended for the majority of digestion applications
DWK Life Sciences Kimble™ Kontes™ Dilatometer
Provides empirical measurement of solid fat content of shortenings, margarine oils, and other fats with solid index of 50 or less at 10°C
Labconco™ Kjeldahl Rapid Digestor-4
Digests all types of samples in about 25-45 minutes, depending on sample type and catalyst
DWK Life Sciences Wheaton™ Scrubber Absorber Tube
For arsenic analysis using silver diethyldithiocarbamate (SDDC) colorimetric method
Labconco™ Glass Manifold
Make exhaustion of fumes from Kjeldahl digestions more convenient by adding a Labconco Glass Manifold to your system.
Labconco™ Kjeldahl Digestion Tubes for Rapid Digestor-4 and Rapid Digestor-25
For Rapid Digestor-25 and Rapid Digestor-4
Parr™ Microwave Acid Digestion Bomb
For high-speed heating: 20- to 30-minute cycle time, including cooling.
Scientific Device Snap n' Digest™ Digestion System
Simple and inexpensive fluid processing of mycobacterial specimens
Foss™ Kjeldahl Digestion Systems
Digestion units can be combined with a range of accessories to match individual needs. Auto models come include integrated programmable controllers.
Foss™ Digestion System: Scrubber Units: SR210, automatic version
For neutralization of corrosive fumes in acid digestions
Typically performed on foodstuffs, the Kjeldahl method or test is designed to determine (or confirm) the amount of protein in soil, wastewater, fertilizer, and other materials. They are used in agricultural and environmental testing to measure trace metals, nitrates, and ammonium.
The method converts proteins, amines, organic compounds and other nitrogen compounds into ammonia compounds. A caustic is added to release the ammonia, which is then distilled and titrated. Samples are heated from 360o to 410°C in the presence of concentrated sulfuric acid and a catalyst. This decomposes or digests the sample and frees the nitrogen. The digestion is complete when the liquid is clarified and the fumes are released. The samples are cooled, and the liquid is distilled and titrated.
Several catalysts are available (called Kjeldahl tablets), and usually contain a mixture of copper and titanium. Some catalysts work better with specific materials, and others are more environmentally friendly. Digestions can be performed manually, but are somewhat hazardous and should always be performed under a chemical hood.
Automated or semi-automated digestors reduce the risk to the person performing the Kjeldahl testing. Some equipment is designed to heat to the maximum temperature in an hour and cool down faster for more efficient digestions. Some perform only the digestion portion of the procedure, and the distillation and titration must occur separately. More complete digestion systems incorporate all of the necessary steps and deliver a final result. The choice of digestor type, including rapid digestors, depends on the workload, speed required, and sample volume.