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Table 4 Principal positive ions that decrease during aging. Retention time, measured m/z, calculated m/z, postulated identity, and elemental composition of positive ions that decrease during aging.

From: Metabonomics evaluations of age-related changes in the urinary compositions of male Sprague Dawley rats and effects of data normalization methods on statistical and quantitative analysis

Retention time (min) Measured m/z (Da) Calculated m/z (Da) Postulated identity (with tR of standard) Elemental composition of [M+H] ion
3.87 297.1445 297.1450   C14H21N2O5
3.88 303.0738    
4.91 305.1582 305.1576   C12H26O7Na
5.24 349.1832 349.1838   C14H30O8Na
5.91 431.0992    
6.82 233.0963    
6.87 447.0938    
8.91 410.1856