Micro Kjeldahl Nitrogen Distillation Apparatus

Integrated Steam Generation Matrix: Features a specialized internal steam chamber designed to maintain constant vapor pressure, ensuring the rapid liberation of volatile nitrogenous components while preventing sample foaming and thermal degradation.

Hermetic 1:10 Taper Joint System: Engineered with CNC-ground interchangeable joints and a reinforced splash head that prevents alkaline entrainment, maintaining absolute distillate purity for high-accuracy titrimetric results in micro-analytical workflows.

$13.59

Quick Answer: A micro Kjeldahl apparatus is a compact glass steam-distillation unit that releases ammonia from a small portion of a digested sample and delivers it to a receiving acid for titration. It is used to measure nitrogen and protein on small samples in biochemistry, food and pharmaceutical laboratories.

Steam Distillation on a Small Scale

Micro Kjeldahl distillation units are commonly of the Parnas-Wagner or Markham pattern: a steam generator, a small inner distillation chamber and a condenser, joined into one assembly. A measured aliquot of the digest is rinsed into the chamber through a small funnel with a stopcock, followed by sodium hydroxide solution. Steam from the generator then sweeps through the alkaline mixture, carrying the ammonia to the condenser and into boric acid in the receiver.

Because steam rather than a flame heats the sample, the distillation is gentle and quick, and the chamber can be emptied and rinsed without dismantling anything. In the usual designs, interrupting the steam supply lets the generator cool, and the drop in pressure draws the spent liquid out of the chamber, ready for the next aliquot. Small samples and reagent volumes also mean less acid fume in the digestion stage and less waste.

The listing does not state the pattern, the capacity of the steam generator or whether a heater is included. For whole-digest distillation in a large flask, compare the Kjeldahl distillation assembly; the digestion itself is carried out in a Kjeldahl flask.

Applications

Protein estimation in biochemistry practicals on milk, egg albumin or cereal flours
Nitrogen content of small plant, tissue or pharmaceutical samples where material is limited
Recovery checks with a known ammonium sulfate standard to validate technique
Research laboratories running many small nitrogen determinations in a day

Specifications

Method	Steam distillation of ammonia from a digest aliquot
Common patterns	Parnas-Wagner or Markham type glass units
Sample scale	Small aliquots containing milligram amounts of nitrogen
Receiver	Boric acid with mixed indicator, titrated with standard acid
Pattern, heater and generator size	Confirm at enquiry

Care & Handling

Use distilled water in the steam generator and drain it regularly to prevent scale and carry-over of impurities.
Steam out the unit for a few minutes before the first sample of the day to remove traces of ammonia.
Rinse the sample funnel into the chamber with small portions of water so no digest is left on the glass.
Support the assembly on its own stand with padded clamps, since the glass links between generator, chamber and condenser are vulnerable to strain.

Why Choose LabEquip

Biochemistry departments, food science courses and pharmaceutical QC labs choose a micro Kjeldahl apparatus when sample sizes are small and many determinations are needed. The unit appears in LabEquip’s chemistry lab equipment; confirm the pattern and heating arrangement on the contact page.

Frequently Asked Questions

How does micro Kjeldahl differ from the macro method?

The chemistry is the same, but the micro method digests a small sample and distils only a measured portion of the digest by steam. It uses less acid and alkali, produces less fume and waste, and each distillation takes only a few minutes.

What is a Parnas-Wagner apparatus?

It is a common glass micro Kjeldahl still in which steam from a separate boiling flask passes through an inner chamber holding the alkaline digest. The ammonia is carried to a condenser and collected in acid.

How is the chamber emptied between samples?

In the usual designs, stopping the steam supply lets the generator cool, and the pressure drop draws the spent liquid from the inner chamber into an outer jacket or trap, from which it is drained. The chamber is then rinsed with water.

Why use a mixed indicator in the boric acid?

Mixed indicators such as bromocresol green with methyl red give a sharp colour change at the end point of the titration of ammonium borate with standard acid, which matters when the titre is small.

How can I check that the apparatus recovers all the ammonia?

Distil a known amount of a pure ammonium salt, such as ammonium sulfate, and compare the nitrogen found with the amount taken. Recoveries close to the expected value show the unit is working correctly.

Can tap water be used in the steam generator?

Distilled water is preferred. Tap water leaves scale in the generator and can carry traces of ammonia or dissolved salts into the steam, which affects small results.

Last Updated: September 2026