REPORT FOR ANALYTICAL CHEMISTS
SPECIAL
FLOW GAS 8.5% 91.5%
Hydrogen Helium
For use as a carrier gas to make a hydrogen signal respond in a linear basis when using a thermal conduc tivity type gas chromatograph. Matheson is the world's leading supplier of high purity gas mixtures. Custom and stock mixtures of 95 gases available from mixing laboratories in 5 plants. Write for catalog.
MATHESON East Rutherford, N.J.
Forest Park. Ga . Joliet. III., La Porte. Texas. Newark Calif
Matheson of Canada, Whitby, Ont. "or more — from Matheson Circle No. 172 on Readers' Service Card
Specify SPECTROQUALITY ®
PYRIDINE U.V. Cut-off
THE COLEMAN CARBON AND HYDROGEN ANALYZER
305 n v
Evap. Residue Moisture Fluorescence
.0002% max. .05% max. .3 ppb as quinine base max. A versatile polar solvent; miscible in all proportions with water, alcohols and ether; soluble in fats, oils and most of the common organic solvents including esters, ethers, ketones, alphatic and aromatic hydro carbons; used as a solvent for both organic and inorganic compounds; dipole moment 2.20D. Comparative tests prove MC&B Spectroquality Solvents are the highest quality most complete line of solvents for spectro photometry and fluorometry. Write for wall chart showing UV, IR, and NIR transmittance of 40 Spectroquality solvents.
Division
of The Matheson Co.,
Norwood
(Cincinnati)
Inc.
O., East Rutherford,
Ν. Υ.
Circle No. 173 on Readers' Service Card
36 A
·
Figure 1 and Figure 2. The Coleman Carbon and Hydrogen Analyzer and Schematic Flow Diagram
ANALYTICAL CHEMISTRY
While not an automatic analyzer in the sense of some of the other offer ings, one of the simplest pieces of equipment being commercially offered is the Coleman Carbon and Hydrogen Analyzer shown in Figure 1. This ap paratus is basically a programmed Pregl carbon and hydrogen train housed in a shell which is similar to the Nitrogen Analyzer offered by the same com pany. The apparatus differs from the conventional Pregl apparatus in the following manner: the combustion tube is replaced before each determina tion, the sample and a fresh portion of filling being placed in the tube; and then the tube is placed in the combustion position. The sample is burned by two furnaces that automatically move into place over the combustion tube and retract when the burning cycle is completed. The products of combustion are absorbed on the conventional Ascarite and Anhydrone re agents; manganese dioxide is used to retain the unwanted oxides of nitrogen. Novel absorption tubes are employed, having no glass capillary constrictions and being held in a spring loaded device, they are easily slipped out of the apparatus for weighing. Wiping of the tubes is not required. The flow of oxygen and the required sequence of operation is controlled by an electrical timer. A schematic flow diagram of the Coleman Carbon and Hydrogen analyzer is shown in Figure 2. Following is the sequence of operation for a single determination; a sample of two to fifty milligrams in weight is weighed into a small aluminum foil boat; the boat containing the sample is then placed into the combustion tube which has been previously partly filled with the
