CHNS/O Dynamic Flash Combustion Elemental Analyzer

What is the CHNS/O Dynamic Flash Combustion Elemental Analyzer?

A CHNS/O elemental analyzer flash-combusts a milligram-scale sample at about 1000 °C and separates the resulting gases for thermal conductivity detection. It reports carbon, hydrogen, nitrogen and sulfur, and with pyrolysis oxygen, in chemicals, coal, polymers, fertilizers and organic intermediates.

Overview

A tin-encapsulated sample of 1–5 mg drops into a quartz reactor held at 950–1050 °C, and a timed oxygen pulse causes exothermic flash combustion exceeding 1800 °C. Gases pass over copper to reduce nitrogen oxides to N2 and remove excess oxygen, then enter a chromatographic column or adsorption trap system that separates N2, CO2, H2O and SO2 for thermal conductivity detection with helium carrier. For oxygen, the sample is pyrolyzed at 1060 °C over nickel-coated carbon, converting oxygen to CO. Precision is typically better than 0.2% absolute for C, H and N. Autosamplers handle 60 to 120 samples. Particular care is required for volatile or hygroscopic samples, which must be sealed in tin or silver capsules and weighed quickly.

How does it work?

Elemental analyzers convert the element of interest into a simple gas at high temperature and then measure that gas. In combustion analysis, a sample burns in oxygen at 900–1350 °C, converting carbon to CO2, hydrogen to H2O, sulfur to SO2 and nitrogen to N2 or NOx. Gases are separated by chromatographic column or selective traps and detected by non-dispersive infrared cells, thermal conductivity detectors or chemiluminescence. Inert gas fusion heats a sample in a graphite crucible under helium to release oxygen as CO, nitrogen as N2 and hydrogen as H2, again measured by infrared and thermal conductivity. Induction furnaces heat metals and ores with accelerators such as tungsten and tin. Calibration uses certified standards of known composition.

What are the key features?

• Flash combustion at over 1800 °C inside a quartz reactor held near 1000 °C
• Thermal conductivity detection with chromatographic column or adsorption trap separation
• Separate pyrolysis mode for direct oxygen determination
• Autosampler with 60 to 120 positions and optional inert-gas purge
• Microgram-range balance interface for capsule weighing
• Methods for CHN, CHNS and O configurations on one platform

What are the technical specifications?

A typical chns/o dynamic flash combustion elemental analyzer configuration offers elements of C, H, N, S (O by pyrolysis), sample mass of 0.5–5 mg (up to 100 mg organic, optional), combustion temperature of 950–1050 °C (flash > 1800 °C), pyrolysis temperature of ≈ 1060 °C, detector of Thermal conductivity (TCD) and measuring range (C) of 0.01–100% (absolute). Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The CHNS/O Dynamic Flash Combustion Elemental Analyzer is used in ultimate analysis of coal, coke and biomass, purity check of synthesized organic compounds, nitrogen content of fertilizers and protein-related samples, carbon and nitrogen in soils and sludges and elemental composition of polymers and resins. Across the wider Elemental Analyzers class, laboratories also deploy it for carbon and sulfur in steel and ores, oxygen, nitrogen and hydrogen in metals and alloys and ultimate analysis of coal and coke.

Which standards and certifications apply?

Relevant standards and methods include ASTM E1019, ASTM E1409, ASTM D5373, ASTM D5453, ASTM D4239, ISO 15350, ISO 10694 and IEC 61010-1. Certification candidates for this model are CE, ISO 9001 manufacturing and RoHS; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Elemental analyzers need clean, dry, high-purity gases, typically oxygen and helium or argon at 99.995% or better, with regulators and moisture traps. Condition new combustion tubes, catalysts and reagents according to the manual, and replace them on a usage schedule. Run blanks and conditioning samples at start-up, then calibrate with certified standards that match the expected concentration range, such as acetanilide for CHN or steel standards for C and S. Control dust by cleaning the furnace and filters frequently, especially for ore and coke samples. Check for gas leaks regularly, weigh samples on a balance with suitable readability, and keep crucibles pre-ignited and free of contamination.

How do I select the right CHNS/O Dynamic Flash Combustion Elemental Analyzer?

Select this variant for organic or organic-rich samples where C, H, N and S are reported together, such as coal ultimate analysis or chemical purity. For metals and inorganic solids choose the induction furnace sibling. In an RFQ, list elements, sample types and sizes, need for oxygen mode, autosampler size, gas supplies and standards such as ASTM D5373.

How does it compare with other Elemental Analyzers variants?

Select by element set and sample form. Carbon and sulfur in steel, ores, cement and ceramics point to a high-frequency induction furnace with infrared detection. Oxygen, nitrogen and hydrogen in metals call for an inert gas fusion analyzer. Organic samples requiring C, H, N, S and possibly O suit a CHNS/O dynamic-flash combustion analyzer. Sulfur or nitrogen at mg/kg levels in liquid fuels suit UV-fluorescence or chemiluminescence analyzers. Check measuring range, since percent-level and ppm-level analyses need different detector ranges. Consider sample throughput, autosampler capacity, consumables such as crucibles, anhydrone and catalysts, and the standard methods to be met, such as ASTM E1019 or ASTM D5453.