628 Series Carbon/Hydrogen/Nitrogen Determinator


Maintenance-free autoloader

Simple, gravity-fed autoloader allows for unattended analysis up to 120 samples

Liquid autosampler


The CHN628 represents the fifth generation of LECO Organic Elemental Combustion Instruments.

By incorporating state-of-the-art hardware and software technology with key improvements in overall instrument performance and reliability the CHN628 Series Elemental Determinator is the right choice for wide range of applications in organic matrices from food to fuels.

The instrument is used for CHN/S elements analysis in fuels (coal, coke, oils), chemical processing (resins, adhesives, plastics), agriculture (soil/plant science, feed, flour, oilseeds), nutritional labeling (protein) for foods and feeds and many other applications.

Fast analysis time and flexible configurations— nitrogen/protein, carbon/nitrogen, carbon/hydrogen/nitrogen and sulfur – provide high versatility to fit your needs. Independent detectors used for simultaneous elemental determination, resulting in rapid analysis time.

Unique combustion gas handling and aliquot dosing system significantly extends the lifetime of the reagents used, lowering cost-per-analysis and instrument downtime, while eliminating the need for chromatographic separation techniques and other costly whole gas analyses.


  • Maximize Throughput up to 14 analysis per hour while keeping Cost-Per-Analysis Low
  • Fastest analysis : result within 4 to 5 minutes for all the elements being determined and for all sample masses
  • Complies with AOAC, ASTM, ISO, AACC, and ASBC approved methods
  • Ability to handle macro sample mass to 750mg of solids and up to 1ml of liquids
  • Proven LECO combustion technology, allows system to analyze a wide variety of organic samples with high precision and accuracy under one method and calibration
  • Sulfur add-on module provides independent sulfur determination in less than 2 minutes
  • Simplified data handling, customizable data reporting/exporting
  • Enhance safety and convenience for maintenance routine


The CHN628 utilizes a combustion technique and provides a result within 4.5 minutes for all the elements being determined. Simplified explanation of the operation principle can be summarized as follow: A sample is weighed into a foil or capsule and loaded into autoloader. Simple, gravity-fed autoloader allows for unattended analysis, while increasing long-term reliability of loader. Passing first the purge chamber that is removing atmospheric gas,  the sample is introduced to furnace. Combustion gases are swept from the furnace and passing by the thermo-electric cooler collected into aliquot collection system. Use of thermoelectric coolers in LECO analyzers allows efficient moisture removal without the use of chemicals. Helium carrier gas is utilized to sweep the aliquot gas through two independent IR cells for Carbon and Hydrogen Determination. Future after passing reduction reagent, aliquote gas reaches a thermal conductivity cell for nitrogen  detection. Optional 628 S module is specifically designed to determine the sulfur content in a wide variety of organic materials such as coal, coke, and fuel oils, as well as some inorganic materials such as soil, cement, and limestone. CHN628 software flexible and easy to operate. With virtually unlimited storage space and compatibility with various Laboratory Information Management Systems (LIMS), this software is designed for seamless interaction with any operator or customer environment. A convenient on-board help manual allows quick access to information without leaving the instrument. The software also supports compliance to FDA regulations 21 CFR Part 11 for a closed analytical system.


  • Dual-stage furnace system operates at temperatures up to 1050°C with pure oxygen to ensure the complete combustion of all organic samples, without requiring additional metal oxidizing reagents or other carrier gases
  • Quartz lance directs oxygen flow directly onto the sample, accelerating the combustion process and providing superior recovery
  • Large, porous crucible aids combustion process and extends maintenance intervals reducing ash
  • Ballast and Aliquot Combustion Gas Handling system significantly extends lifetime of carbon scrubber and reduction reagents
  • To increase even more convenience of use, the  CHN628 has open access to ballast and pinch valve assembly areas with quick-release features to simplify preventive maintenance routines
  • Fast replacement tubing kits available with sealed unions and fittings for quick service


LECO’s versatile instrumentation can be used to perform a wide range of applications. Please find below a selection of application notes for the most popular applications. Contact our sales and application specialists for more details.

Determination of Carbon, Hydrogen and Nitrogen in Biomass

Fast, reliable and matrix independent, the LECO CHN 628 determines the elemental composition of all kind of biofuels in just 4-5 minutes. The instrument can be equipped with an additional module for Sulfur and Oxygen content analysis.Learn more...

Sulfur in Hydrocarbons

Sulfur in Petroleum Products by ASTM D1552. Learn more...

Hydrocarbons analysis

Carbon, Hydrogen, and Nitrogen in Hydrocarbons by LECO CHN628. Ref: 203-821-462Learn more...

Soil and Plant Tissue

Simultaneous Carbon/Nitrogen in Soil and Plant TissueLearn more...

Coal and Coke

Carbon, Hydrogen, and Nitrogen in CoalLearn more...

Coal and Coke

Carbon, Hydrogen, and Nitrogen in CokeLearn more...

Options & models


Various options are available for this product. Contact our sales and application specialists to select the right configuration for your application.
628 Sulfur Add-On Module Provides independent sulfur determination on macro samples (350 mg) in less than 2 min
Autoloader Maintenance-free autoloader with optional capacity for up to 120 samples
Liquid Autosampler Dedicated liquid auto sampler controlled by the software. Available for nitrogen and carbon/nitrogen configurations
Online diagnostic LECO's convenient remote diagnosis via Internet


Each instrument can be configured to meet your individual lab needs. Contact our sales and application specialists to select the right configuration for your application.
CHN628C Carbon/Hydrogen/Nitrogen Determinator with loader, PC and LECO application software
CN628C Carbon/Nitrogen Determinator with loader, PC and LECO application software
FP628C Nitrogen / Protein Determinator with loader, PC and LECO application software