Análise de Carbono, Hidrogênio, Nitrogênio, Enxofre e Proteínas de Materiais Orgânicos

Introdução

The LECO 828/928 Series instruments are high-performance combustion analyzers designed for fast, accurate determination of carbon, hydrogen, nitrogen, sulfur, and protein across a broad range of organic materials including foods and feeds, soils and plant tissues, solid fuels, plastics, and fertilizers. This series provides the flexibility, precision, and productivity required for confident elemental and protein determination in modern analytical workflows.

Dumas Method for Protein Determination

FP828 and FP928 models determine nitrogen, and by extension, protein using the Dumas combustion method: a quicker and less hazardous alternative to traditional Kjeldahl analysis. In this process, a precisely weighed sample is combusted in a high-temperature, whole oxygen environment, converting its nitrogen content into NO_x. The resulting NO_x is reduced to N₂ and measured by a thermal conductivity detector, providing accurate determination of total nitrogen.

Once nitrogen is quantified, the instrument applies a protein factor to generate reliable protein values for foods and feeds. Because Dumas analysis requires no corrosive reagents, digestion steps, or hazardous waste handling, it delivers a cleaner, faster, and more sustainable workflow than wet chemical methods, making it ideal for laboratories prioritizing speed, safety, and accurate protein results.

Solid Fuels Analysis

The CHN828 combines large sample mass capability with a high-efficiency, whole oxygen combustion system to ensure accurate analysis of challenging fuel matrices such as coal, coke, biomass, and other alternative fuels. By promoting complete sample combustion without the need for additional oxidizing reagents, the system delivers reliable carbon, hydrogen, and nitrogen results across a wide range of fuel types. Fast analysis times, extended reagent lifetimes, and flexible carrier gas operation help laboratories maximize productivity while minimizing operating costs, making the CHN828 an ideal solution for both routine quality control and advanced fuel research applications.

For laboratories requiring sulfur determination, the optional S832 add-on furnace expands the CHN828’s capabilities by adding independent sulfur analysis. Together, the CHN828 and S832 provide a complete solution for CHNS determination across a wide variety of materials. When combined with LECO’s TGA801 for moisture, volatile matter, and ash analysis and AC Series calorimeters for calorific value determination, laboratories can obtain the critical analytical data needed to evaluate fuel composition, quality, performance, and value.

Soil and Plant Tissues

The CNS928 combines macro sample mass capability with a robust, whole oxygen combustion system to deliver accurate carbon, nitrogen, and sulfur analysis for soils and plant tissues. Designed to accommodate heterogeneous sample types and varying concentrations, the system provides reliable elemental results while maintaining the productivity and ease of operation required in modern agricultural and environmental laboratories.

Whether supporting soil health assessments, nutrient cycling studies, crop research, or routine testing services, the CNS928 delivers the analytical performance needed for both high-volume laboratory operations and advanced research applications. Fast analysis times, extended reagent lifetimes, and simplified routine maintenance help maximize sample throughput while reducing operating costs. Combined with Cornerstone software, the system streamlines data management, method control, and reporting for efficient day-to-day operation.

As part of LECO’s broader agriculture and environmental testing portfolio, the CNS928 complements technologies such as the TGM800 for moisture determination and the TGA801 for moisture and ash analysis. Together, these solutions provide the data needed to better understand soil composition, evaluate plant nutrient uptake, monitor organic matter, and support agricultural research and production decisions with confidence.

How the LECO 828/928 Series Works

The LECO 828 and 928 Series determine carbon, nitrogen, protein, hydrogen, and sulfur (depending on configuration) in a wide range of organic matrices, including food and feed materials, soils, fertilizers, fuels, and related organic samples using high-temperature combustion analysis. Samples are introduced into a pure oxygen environment, where they are completely oxidized and converted into measurable gases without the use of additional oxidizing reagents.

The combustion gases are collected in a ballast, where they are mixed and stabilized before a representative aliquot is transferred through the analytical system using helium or argon. This approach helps ensure accurate and repeatable measurements across a wide range of sample types. Carbon, hydrogen, and sulfur are measured using non-dispersive infrared (NDIR) detection, while nitrogen is measured using a thermal conductivity (TC) detector.

While both platforms use the same analytical principles, the 828 Series is optimized for high-throughput routine analysis utilizing a vertical quartz combustion tube and lance, while the 928 Series is designed to accommodate larger sample masses and more demanding materials using a high-temperature horizontal ceramic furnace and oxygen lance.

LECO’s Cornerstone brand software supports efficient operation by interleaving sample loading with quantitation of gases from the previous sample, helping maximize sample throughput. The software also provides access to analysis control, method settings, diagnostics, reporting, real-time ambient monitoring, animated system diagrams, data grouping, automatic statistics, LIMS compatibility, multilingual interface support, user permissions, and flexible reporting. Results can be displayed in common reporting units such as weight percent or parts per million, with other custom units available if preferred.

Métodos Aplicáveis

The LECO 828 & 928 Series conform to estes métodos aprovados.

AOAC 990.03 Crude Protein in Animal Feed

AOAC 992.15 Crude Protein in Meat, Meat Products, and Petfoods

AOAC 992.23 Crude Protein in Cereal Grain and Oil Seed Products

AOAC 993.13 Nitrogen in Fertilizer

AOAC 997.09 Nitrogen and Protein in Beer, Wort, and Brewing Grains

Suporte a Instrumentos

Ensure reliable instrument performance with extensive support, training, and maintenance services. Need tailored support for your elemental analyzers? Our experts are standing by.