Total Inorganic Carbon Analysis

By Acidification and Coulometric Detection

Applications include: Carbonates in pharmaceuticals, Dissolved carbon dioxide in sea water, Carbonates in geological materials, Carbon dioxide in amine and hydrazine, Carbonates in black liquors, Carbonates in food

Conforms to ASTM D 513

The CM140 Total Inorganic Carbon Analyzer is a complete analytical system allowing the direct measurement of total inorganic carbon in a wide variety of sample matrices and concentrations. Combining a self-contained unit for the acidification of a sample (to evolve CO2), with a highly sensitive CO2 detector, the CM140 easily handles solid or liquid samples with concentrations from ppm levels to 100% inorganic carbon without user calibration. UIC’s analyzers are rugged, accurate and adaptable to most TIC applications. They are used extensively in industrial, research and educational laboratories worldwide. The CM140 system includes the following components pictured above:

CM5014 CO2 Analyzer

-No user calibration-Wide, linear dynamic range

-Readability to 0.01 ug Carbon

-User selectable display units

-Floppy disk drive for archiving data

CM5130 Acidification Module

-10, 25, 50 or 100 ml reaction vessels

-Selectable volume acid dispenser

-Internal air pump with flow controller

-Pre-acidification scrubber for removal of CO2 from carrier gas

-Post-acidification scrubber for removal of interferents released during sample digestion

-Controlled sample heating

Instrument Capabilities

A major advantage of the CM140 Total Inorganic Carbon Analyzer is the use of coulometric detection. Employing the principles of Faraday’s Law, the CM5014 CO2 Analyzer automatically measures the absolute mass amount of carbon dioxide resulting from sample combustion. No user-calibration is required and linear detection is available from less than 1 ug carbon to over 10,000 ug carbon. Using this 100% efficient coulometric process, relative standard deviations of 0.2% or better are common for standard material. For smaller concentrations, an absolute deviation of approximately 1 ug C is typical.

Additionally, it is possible to analyze either solid or liquid samples. Sample flasks are available in 10, 25, 50 and 100 ml sizes (with sample volume or mass determined by carbon concentration and desired level of accuracy). Solids or liquids may be weighed directly into the sample flasks. Alternatively, liquid samples may be syringe injected through a septum.

Oxidation times vary with sample type and temperature although 5 to 7 minute analyses are typical. To quicken CO2 evolution, sample heating and stirring capabilities are included within the CM5130 Acidification Module. Other features include the ability to: select different acids; add wetting/emulsifying agents; and, modify the flow path and scrubbers to optimize a particular application.

Principles of Operation

Total Inorganic Carbon (TIC)

Upon introducing a sample into the sample flask, the system is purged with a CO2-free carrier gas to eliminate atmospheric carbon dioxide. At that point, the analysis is initiated by adding an aliquot of acid through the acid dispenser into the sample flask, causing inorganic carbon to be evolved as CO2. Using the built-in heater and magnetic stirrer to facilitate the fast evolution of inorganic carbon, the CO2-freecarrier gas transports the reaction products through a post-scrubber (to remove potential interferences) and ultimately into the reaction cell within the CM5014 Analyzer. There, the resulting carbon dioxide is automatically measured using absolute coulometric titration.

Data Handling

Names, weights, volumes or areas of up to 50 samples can be entered to be used by the CM5014 in calculating the final result. Analytical progress is digitally displayed in user-selectable units. A detailed report is printed while each sample is running that includes the final result. Upon completion of a series of samples, a one page report will print, summarizing the analysis of all 50 samples. The results can also be stored to diskette for further data handling.

CM140 - Total Inorganic Carbon in Solids or Liquids

Includes: CM5014 CO2 Coulometer and CM5130 Acidification Module with tools and accessories for the analysis of solid or liquid samples. Must also choose either the CM5131, CM5132, CM5133 or CM5134 Sample Introduction Kit. (P/N CM140-01 115V, 50/60Hz) (P/N CM140-02 230V, 50/60Hz)