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Determining the carbon, hydrogen, nitrogen, oxygen and sulfur content of unknown samples is one of the most basic and essential needs for any chemist.
When measurement for CHN/O/S, CE-440 elemental analyzer can increase productivity and maximize confidence in analysis results.
CE-440 is designed to obtain accurate and reliable results, no matter what sample types analyze.

CE-440 uses thermal conductivity detection for measuring carbon, hydrogen and nitrogen, after combustion and reduction. This time-proven technique allows measurements to be implemented over a very wide range of concentrations. Unique horizontal furnace allows for automatic removal of the residue from each sample after analysis, avoiding memory effects and gas flow problems, which can occur with vertical furnace systems.

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CHN Elemental Analyzer CE-440


Automatic type(64 carousels)      Manual type


  • Rapid analysis for high productivity — analysis time of less than 5 minutes
  • Unique combustion technique makes it possible to analyze any sample type, from volatiles to refractories
  • Stable thermal conductivity detector provides linear response with superior precision and accuracy
  • Windows R software with data storage for statistical analysis and flexible report generation
  • Horizontal sample injection removes interfering residue between each sample run
  • Continuous diagnostic with automatic maintenance alerts
  • Low reagent consumption — industry’s lowest cost per sample

The products of combustion are passed over suitable reagents in the combustion tube to assure complete oxidation and removal of undesirable byproducts such as sulfur, phosphorous and halogen gases. In the reduction tube, oxides of nitrogen are converted to molecular nitrogen and residual oxygen is removed. In the mixing volume, the sample gasses are thoroughly homogenized at a precise volume, temperature and pressure. This mixture is released through the sample volume into the thermal conductivity detector.

Between the first of three pairs of thermal conductivity cells, an absorption trap removes water from the sample gas. The differential signal read before and after the trap reflects the water concentration and, therefore, the amount of hydrogen in the original sample. A similar measurement is made of the signal output of a second pair of thermal conductivity cells, between which a trap removes carbon dioxide, thus determining the carbon content. The remaining gas now consists only of helium and nitrogen. This gas passes through a thermal conductivity cell and the output signal is compared to a reference cell through which pure helium flows. This gives the nitrogen concentration.

For oxygen analysis, the combustion tube is replaced by a pyrolysis tube containing platinized carbon. The reduction tube is replaced by an oxidation tube containing copper oxide. The sample is handled and run as before, but is now pyrolyzed in helium so that carbon monoxide is formed from oxygen in the sample. The CO is oxidized by the copper oxide to form carbon dioxide, which as detected and measured in the same manner as the carbon analysis.

For sulfur analysis, the combustion tube is replaced with one containing a tungsten oxide packing plus a dehydration reagent. The water trap is removed and replaced with silver oxide to absorb SO. The sample is handled and run as before, but the sulfur from the sample is oxidized to form SO2, and the water formed is removed. The SO2 is detected and measured in the same manner as the hydrogen analysis.

  • Organics and Pharmaceuticals — Can analyze virtually any class of organics, including organo-metallics, heterocyclic nitrogen derivatives, steroids, poly-nuclear aromatics and organo-phosphorous
  • Environmental — Analyze the effect of fuels, oils and their byproducts on the environment, or investigate the composition of material retained by membranes used in oceanography, water filtration and air monitoring
  • Polymers — Provides a fast, direct method for determining elemental composition of polymers, copolymers and blends; even samples with high levels of halogens like PVC or Teflon R, can be analyzed rapidly and accurately
  • Refractories — Nitrides, graphite fibers and ceramics are easily analyzed; even carbides with melting point over 2000℃
  • Volatile/Air sensitive samples — Volatile and air sensitive samples are easily analyzed using capsule sealing device
  • Other application areas — Plastics, petrochemicals, agriculture, food and pyrotechnical compounds
Accuracy and precision

The most important criteria for CHN analysis in the majority of analytical laboratories are for optimal; accuracy and precision across a wide range of sample types. With constant pressure to increase laboratory productivity, an analyst does not want to set up their analyzer with different operational parameters for every different sample type they come across. The following figure indicates a set of data, for accuracy and precision testing with CE-440.

Stability

The calibration constant relates the number of micro-volts detected to each microgram of element. A run of 60 samples (including 11 standards) were analyzed under normal conditions. To maintain an accuracy of 0.3% absolute, the maximum deviations of the calibration constants allowed should be approximately C=0.08, H=2.75, and N=0.22. the data in the following figure run on CE-440 shows that all the calibration constants easily within meet these criteria.