Quantitative Analysis of Sialic Acids by

Another approach has been published by Roboz et al. (1978). Neu5Ac was released from glycoproteins by sialidase or by acid hydrolysis and subsequently trimethylsilylated with N,0-bis(trimethylsilyl)-trifluoroacetamide plus 1% chlorotrimethylsilane and pyridine (3 1) for Ih at 100 °C, also leading to trimethylsilylation of the N-acetyl function. As the internal standard trimethylsilylated Neu p-methyl glycoside was used. The quantification was carried out with g.l.c./c.i.-m.s. (isobutane) using the intense peak at mje 814 [(M-l-H) ] for Neu5Ac and the intense peak at mje 714 [(M -I-H) ] for the internal standard. The detection limit for pure Neu5Ac is 200 pg. The method has been applied in the study of leukemic myeloblasts. 

Miyatake et al. (1979) reported the use of mass fragmentography in sialidase activity studies. For the analysis of released Neu5Ac, the carboxyl group as well as the various hydroxyl functions were trimethylsilylated. As the internal standard the trimethylsilylated derivative of N-acetylgalactosamine a-phenyl glycoside was 

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