Combustion CHNS/O Organic Elemental Analyzer

What is the Combustion CHNS/O Organic Elemental Analyzer?

A combustion CHNS/O organic elemental analyzer burns milligram samples at about 1000 °C and measures C, H, N, S, and optionally O with a thermal conductivity detector. It is the general-purpose choice for organic, pharmaceutical, and polymer laboratories.

Overview

This platform is the classic Pregl–Dumas design. A sample of 1–5 mg in a tin capsule falls from an autosampler into a reactor at 950–1150 °C, where an oxygen pulse triggers flash combustion. Gases pass over copper to reduce nitrogen oxides and absorb excess oxygen, are separated on a packed GC column or by temperature-programmed desorption, and are measured by a thermal conductivity detector. Sulfur is detected as SO2, and an optional pyrolysis reactor determines oxygen as CO. Typical run time is under 10 minutes and accuracy is within 0.3% absolute for pure standards. Because the method is destructive and uses small sample mass, it requires fine, homogeneous material and accurate microbalance weighing. It is the reference technique for publishing compound purity in synthetic chemistry and for verifying API intermediates.

How does it work?

Elemental analyzers decompose a sample completely, so the element of interest can be measured regardless of its chemical form. Combustion systems burn organic samples in oxygen at about 1000 °C and detect CO2, H2O, N2, and SO2 by thermal conductivity or infrared cells. Inert gas fusion melts metals and ceramics in graphite crucibles, releasing oxygen as CO, and nitrogen and hydrogen as N2 and H2. Induction furnace analyzers combust metals in oxygen and detect CO2 and SO2 by infrared. For liquid fuels, UV fluorescence detects SO2 excited at about 215 nm and chemiluminescence detects nitric oxide reacting with ozone. Combustion ion chromatography absorbs halogen gases into solution and separates the anions on an ion-exchange column. All methods are calibrated against certified standards and require blank control.

What are the key features?

• Flash combustion up to 1150 °C with oxygen pulse for complete oxidation.
• Single-run determination of C, H, N, and S from a few milligrams.
• Optional pyrolysis mode measures oxygen directly as CO.
• Autosampler of 50–120 positions with software calibration and audit trail.
• Low helium consumption options reduce operating cost.

What are the technical specifications?

A typical combustion chns/o organic elemental analyzer configuration offers elements measured of C, H, N, S (O optional), sample mass of 1–10 mg, detection range of 0.01–100% per element, accuracy on pure standards of Within 0.3% absolute, repeatability (RSD) of ≤0.2% for acetanilide and combustion temperature of 950–1150 °C. 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 Combustion CHNS/O Organic Elemental Analyzer is used in organic compound purity confirmation, pharmaceutical intermediate testing, polymer composition and catalyst and MOF characterization. Across the wider Elemental Analyzers class, laboratories also deploy it for materials composition verification, petroleum and fuel quality testing and polymer and electronics halogen screening.

Which standards and certifications apply?

Relevant standards and methods include ASTM E1019, ASTM D5373, ASTM D5453, ASTM D4629, ISO 10304-1, ASTM D7359, ISO/IEC 17025 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Elemental analyzers require stable power, clean dry gases of 99.99–99.999% purity, and exhaust extraction for SO2 and combustion gases. Microbalance-based systems need a vibration-free bench and temperature stability within about 2 °C. Calibrate with certified reference materials at installation, after maintenance, and at defined intervals, and run check standards at the start of each batch. Consumables such as combustion tubes, crucibles, and traps have defined lifetimes based on sample count. Samples must be homogeneous, dry, and free of surface contamination. Laboratories under ISO/IEC 17025 or GLP should keep calibration records, balance certificates, and maintenance logs, and validate methods on matrix-matched standards. Electrical safety of laboratory equipment is commonly assessed to IEC 61010-1.

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

Choose this platform for routine organic analysis of C, H, N, and S in milligram samples. It is not suited to metals or liquids at ppm levels. In an RFQ, specify elements, need for oxygen mode, autosampler size, microbalance, and helium supply or consumption limits.

How does it compare with other Elemental Analyzers variants?

Choose by the element and matrix rather than by instrument name. Organic powders needing C, H, N, S call for a flash combustion analyzer, and metals needing oxygen, nitrogen, or hydrogen need inert gas fusion. Carbon and sulfur in steel and minerals call for an infrared induction furnace analyzer. Sulfur and nitrogen at mg/kg levels in liquid fuels call for UV fluorescence and chemiluminescence analyzers. Total halogens and sulfur in polymers, electronics, or waste point to combustion ion chromatography. Next specify concentration range, sample mass, required standards, autosampler capacity, and throughput. Ask suppliers for repeatability on reference materials representing your matrix, and confirm consumable requirements such as crucibles, catalysts, reagents, and high-purity gases, since these often dominate operating costs.