[Distribution of organic and inorganic carbon in tissues containing calcium carbonate by secondary ion emission...

The differences of emissivity of secondary ions at masses 12 (C+ and C-), 24 (C2-) and 26 (C2H2- or CN-) of organic moitie and CO3Ca of semi thin sections of egg shell of quail allow the distinction between organic and inorganic carbon on images obtained with Secondary Ion Mass Spectroscopy. There differences of emissivity do not correspond only to the difference of concentration but to the difference of ionic yield. The emissivity at mass 26 (C2H2- or CN-) is higher than those obtained at mass 24 (C2-) in glycoproteinic material (rich in Nitrogen) and lower in the embedding material (Araldite, poor in Nitrogen). This result indicates that the ion present at mass 26 could by CN- rather than C2H2-.