570 



FRED M. UBER 



racy of better than 1%, the over-all accuracy of the dilution method 

 depends primarily on the purity of the individual isolated fractions. 

 As already pointed out, these fractions need not be quantitative ex- 

 tractions and consequently greater latitude is permitted in seeking a 

 higher purity. Where several components are to be analyzed from a 

 single solution, with all of them having been enriched by the same 

 isotopic element, all individual errors are reduced somewhat percent- 

 agewise owing to mutual cross contamination of their respective im- 

 purities (2, p. 565). 



5. Gas Analysis 



To date, the use of the mass spectrometer for gas analysis has 

 been confined almost exclusively to the petroleum industry {7,18). 



20 



50 



60 



30 40 



^/lASS NUMBERS W/e) 



Fig. 1. Typical mass spectra of a few organic molecules. 



When mass spectrometers are more commonly available, it would seem 

 that they might be used extensively for gas analysis in connection 

 with biological problems. Their ability to analyze 0.1 cc. (NTP) 

 gas samples quantitatively for a number of hydrocarbons should cer- 



