Electrothermal Macro / Micro Kjeldahl Equipments
from Bibby Scientific
This product line is no longer available through us.
For food analysis.
- The Macro & Micro-Kjeldahl equipment consists of multi-mantles with 2 or 6 positions which heat to an ultra-high temperature.
- Both can be used for the Kjeldahl analysis to determine protein content in food.
Kjeldahl Method for Protein Content.
- The method consists of heating a substance with sulphuric acid, which decomposes the organic substance by oxidation to liberate the reduced nitrogen as ammonium sulphate.
- In this step potassium sulphate is added to increase the boiling point of the medium (from 169°C to 189°C).
- Chemical decomposition of the sample is complete when the medium has become clear and colourless (initially very dark).
- The solution is then distilled with sodium hydroxide (added in small quantities) which converts the ammonium salt to ammonia.
- The amount of ammonia present (hence the amount of nitrogen present in the sample) is determined by back titration.
- The end of the condenser is dipped into a solution of boric acid.
- The ammonia reacts with the acid and the remainder of the acid is then titrated with a sodium carbonate solution with a methyl orange pH indicator.
- Degradation: Sample + H2SO4 --> (NH4)2SO4 + CO2 + SO2 + H2O.
- Liberation of ammonia: (NH4)2SO4 + 2NaOH --> Na2SO4 + 2H2O + 2NH3.
- Capture of ammonia: B(OH)3 + H2O + NH3 --> NH4 + B(OH)4-.
- Back-titration: B(OH)3 + H2O + Na2CO3 --> NaHCO3 + NaB(OH)4 + CO2 + H2O.
- The Kjeldahl method’s universality, precision and reproducibility have made it the internationally-recognized method for estimating the protein content in foods and it is the accepted standard method.
MQ Series Macro-Kjeldahl Equipment.
- The Electrothermal MQ Series of Macro-Kjeldahl Equipment has been designed for Kjeldahl extraction on a macro scale.
- These multibank units with either 2 or 6 recesses, have a stainless steel outer casing with back-mounted brackets (supplied with each unit), which can hold support rods of 12.7mm diameter max.
- There are 2 volume sizes available for both the 2 and 6 recess models, one for 100-300ml vessels and the second for 500-800ml vessels.
- Each heating mantle has its own energy regulator incorporating an On/Off switch and a “Mains to Heater” amber neon indicator.
- There is also a “Mains On” clear neon indicator on the front panel.
- The lower part of the unit houses dedicated controllers for each recess.
- This “cool zone” housing is separated from the heating element by a stainless steel screen and a well-ventilated air space.
- The heating element consists of thermally insulated element wire stitched into a cartridge, and operates in the temperature range of 550°C to 800°C max.
- All MQ Macro-Kjeldahl Equipment models (except MQ3868B/E)incorporate an earth screen to protect the user from electric shocks and are double-fused for extra safety.
- The rugged stainless steel outer casing is durable and easy to clean.
Technical Specification.
- Heating element temp 550ºC - 800ºC maximum.
- Case material Stainless steel.
- Thermal insulation Ceramic fibre/mineral wool.
- Clamps for support rods Fitted with adjustable clamps to accept the standard arms supplied.
- Wells capacity, ml 100-300.
- Wells dimensions, mm 89 x 45 (diameter x depth).
- Wells capacity, ml 500-800.
- Wells dimensions, mm 117 x 59 (diameter x depth).
Key Features.
- Rugged, easy to clean stainless steel construction.
- Back-mounted brackets hold flask support rods (supplied with each unit).
- Choice of 2 or 6 positions.
- Choice of 2 flask capacity sizes: 100 - 300ml and 500 - 800ml for both the 2 & 6 position models.
- Dedicated controllers for each recess are housed in a “cool zone.
- Grounded stainless steel earth screen covering the heating element.
- Units are double fused for added safety (except for MQ3868B/E which is only available as the 230V model).
MM Series Micro-Kjeldahl Equipment.
- The Electrothermal Micro-Kjeldahl Equipment has been designed for Kjeldahl extraction on a micro scale.
- These multibank units have 6 recesses in a stainless steel outer casing with back-mounted brackets (supplied with each unit), which can hold support rods of 12.7mm diameter max.
- This 6 recess model accommodates flasks of between 18-50ml only.
- Each heating position has its own energy regulator incorporating an On/Off switch and a “Mains to Heater” amber neon indicator.
- There is also a “Mains On” clear neon indicator on the front panel.
- The lower part of the unit houses dedicated controllers for each recess.
- This “cool zone” housing is separated from the heating element by a stainless steel screen and a well-ventilated air space.
- The heating element consists of thermally insulated element wire stitched into a cartridge, and operates in the temperature range of 550°C to 800°C max.
- The MQ Micro-Kjeldahl Equipment models incorporate an earth screen to protect the user from electric shocks and are double-fused for extra safety.
- The rugged stainless steel outer casing is durable and easy to clean.
Technical Specification.
- Heating element temp 550ºC - 800ºC maximum.
- Case material Stainless steel.
- Thermal insulation Ceramic fibre/mineral wool.
- Clamps for support rods Fitted with adjustable clamps to accept the standard arms supplied.
- Wells capacity, ml 18-50ml.
Key Features.
- Rugged, easy to clean stainless steel construction.
- Back-mounted brackets hold flask support rods (supplied with each unit).
- 6 positions which can accommodate flasks of between 18ml - 50ml capacity.
- Dedicated controllers for each recess are housed in a “cool zone”.
- Grounded stainless steel earth screen covering the heating element.
- Units are double fused for added safety.