For research use only. Not for use in diagnostic procedures.
To enter the formula for a stable-isotope-labeled compound in the Components tab of a processing method in SCIEX OS software, some specific rules must be followed. When entering the formula, the atomic mass of the isotope is added before the single letter chemical abbreviation of the element, and then the total number of atoms of each isotope follows the chemical symbol. For example, the chemical formula for a stable isotope labeled version of C24 H45 N12 O8 P3 Cl containing three atoms of deuterium, one carbon-13, one nitrogen-15 and one oxygen-18 would be C23 13C 2H3 H42 N11 15N 18O O7 P3 Cl. The spaces in the formula between each isotope and element are critical. When the formulas are entered into the Chemical Formula column in the processing method, the mass in the Precursor (Q1) Mass (Da) column is automatically calculated and the mass value appears in the column (see figure).