Automatic microanalyzers: VI. Use of a vertical process system

In order to automate the techniques in microanalysis a new series of analyzers utilizing a vertical processing has been developed. Three automatic microanalyzers, i.e., an oxygen, a carbon-hydrogen, and a nitrogen analyzer, are described. For each of them the same type of vertical reactor is used and therefore this design represents an important standardization of this kind of analyzers.Two possibilities for sample introduction are offered. The so-called “automatic introduction device” allows the automatic introduction of the sample into the analyzer; nevertheless it requires the presence of an operator. A fully automated sample introduction is obtained by using the “automatic sample feeder.” This new device can store up to 50 weighed samples and therefore the analyzer runs continuously. These analyzers can carry out an oxygen determination in 7 minutes, a carbon-hydrogen determination in 11 minutes, and a nitrogen determination in 6 minutes. The analyzers can run several hundred determinations continuously.The results reported show a greater reproducibility than that of the results obtained using the classical analyzers, and at least equal accuracy. In addition, the new analyzers have a larger capability; e.g., the oxygen analyzer can determine the oxygen content in organic compounds containing phosphorus and the carbon-hydrogen analyzer allows the determination of the carbon to hydrogen ratio without weighing.