Meaning of "MS1 and MS2 resolution" and "MS1 and MS2: Unit" in a tandem mass-spectrometry parameter list I'm translating a Certificate of Suitability that very briefly describes procedures used to measure several impurities in a drug substance. There is a short description of the parameters of a Gas Chromatography-MS/MS procedure to detect an impurity called NDBA.
I don't understand the final line here:



What is the meaning of Resolution and especially of Unit? I can get by with &quot;resolution&quot; by simply translating it into Russian without knowing what it means, but there is no suitable Russian word to translate &quot;Unit&quot; - I must use either the Russian words for &quot;Unit operation&quot; or for &quot;Equipment unit&quot; or for &quot;Measurement unit&quot;, and I have no idea what this Unit means in the original text.
I tried reading up on MS/MS but I haven't understood it well enough to guess the meaning of this line.
The term &quot;unit&quot; probably means the size of the isolation window used in the QQQ.  The term &quot;unit&quot; means the nominal isolation window is 1 Da (i.e. one mass &quot;unit&quot;) wide.
The &quot;resolution&quot; is a standard term in mass spectrometry, and here they are saying it is about 1 Da.