Abstract
Three standard samples varying in carbon content and three petroleum samples have been analyzed by using CHN Analyzer, Perkin Elmer Model 240.
Some statistic studies on precision and accuracy of the above analytical data were carried out in connection with those by Pregl method. As to the standard samples, the precision of the analytical results were generally satisfactory with a few exceptions while no bias was observed in all cases. As to the petroleum samples, higher hydrogen values were observed when the apparatus had been calibrated by acetanilide, but correct results were obtained by n-nonadecane which had better similarity of the hydrogen content to the petroleum samples. It has been also found that the precision of the analytical data with Perkin Elmer Model 240 depends much upon the reproducibility of the blank value that will be easily influenced by exhaustions of reduced copper (catalyst) and absorbents for CO2 and H2O.
