Complex sentence: In each case, MS instruments divide a particular isotopomer distribution by its molecular weight, meaning that all isotopomers of a particular metabolite contains the same number of labeled carbon atoms are collected in one peak signal.
Split into simpler sentences: In each case, MS instruments divide a particular isotopomer distribution by its molecular weight. All isotopomers of a particular metabolite that contain the same number of labeled carbon atoms are collected in one peak signal.