NOTE
For ease of documenting the first, second, and third rod assemblies as separate pieces of hardware, this manual refers to them as Q1, Q2, and Q3, respectively.
The full scan Q1 and Q3 scan types perform only one stage of mass analysis. The mass spectrum obtained is equivalent to the mass spectrum obtained from an instrument with a single mass analyzer. In the first stage of analysis, the ion source forms ions that enter the analyzer assembly. One of the mass analyzers (Q1 or Q3) is scanned to obtain a complete mass spectrum within a user-defined range. The other rod assemblies (Q2 and Q3, or Q1 and Q2, respectively) act as ion transmission devices. The full scan Q1 scan type uses Q1 as the mass analyzer; the full scan Q3 scan type uses Q3 as the mass analyzer.
Use full-scan type experiments to determine or confirm the m/z (identity) of unknown compounds or the m/z of each component in a mixture of unknown compounds. (Generally, you need a full mass spectrum to determine the m/z of an unknown compound.)
Full scan experiments give you more information about an analyte than the selected ion monitoring (SIM) scan type or the selected reaction monitoring (SRM) scan type, but a full scan does not yield the sensitivity that the SIM and SRM scan types can achieve. Because the full scan type spends less time monitoring the signal for each ion than the SIM or SRM scan types, the full scan type provides greater information but lower sensitivity than the other two scan types.
To perform a SIM experiment or an SRM experiment, you must know what ions or reactions you are looking for. Therefore, you must determine the precursor ion for identifying your analytes before you set up a SIM experiment and the precursor and product ions for your analytes before you set up an SRM experiment. Once you determine these m/z values, you can use the SIM or SRM scan types to run routine quantitative analysis experiments on these analytes.