Method of Single Point Internal Lock-Mobility Correction

A method as claimed in any preceding claim, further comprising:

• separating a second plurality of ions according to their ion mobility and acquiring second ion mobility data;
• applying said revised calibration function to said second ion mobility data;
• and
• determining said estimated property of said second plurality of ions.

A mass spectrometer comprising:

• an ion mobility spectrometer or separator arranged and adapted to separate a first plurality of ions including one or more known or reference ions according to their ion mobility;
• and
• a control system arranged and adapted:
• (i) to acquire first ion mobility data;
• (ii) to apply an initial calibration function to said first ion mobility data;
• (iii) to determine an estimated property of said one or more known or reference ions;
• (iv) to compare said estimated property with a known property of said one or more known or reference ions;
• and
• (v) to vary said initial calibration function to generate a revised calibration function.

A method of mass spectrometry comprising:

• determining an initial calibration function which correlates experimentally determined ion mobility drift times of ions with collision cross sections (“CSS”) of said ions;
• separating a first plurality of ions including one or more known or reference ions according to their ion mobility and acquiring first ion mobility drift time data;
• applying said initial calibration function to said first ion mobility drift time data;
• determining a first collision cross section of said one or more known or reference ions using said initial calibration function;
• comparing said first collision cross section as determined using said initial calibration function with a known collision cross section of said one or more known or reference ions;
• varying said initial calibration function to generate a revised calibration function, wherein a collision cross section of said one or more known or reference ions determined using said revised calibration function correlates more closely with said known collision cross section than said first collision cross section;
• separating a second plurality of ions according to their ion mobility and acquiring second ion mobility drift time data;
• applying said revised calibration function to said second ion mobility drift time data;
• and
• determining a collision cross section of said second ions using said revised calibration function.

A mass spectrometer comprising:

• an ion mobility spectrometer or separator arranged and adapted to separate ions according to their ion mobility;
• and
• a control system arranged and adapted:
• (i) to determine an initial calibration function which correlates experimentally determined ion mobility drift times of ions with collision cross sections (“CSS”) of said ions;
• (ii) to cause a first plurality of ions including one or more known or reference ions to be separated according to their ion mobility in said ion mobility spectrometer or separator and to acquire first ion mobility drift time data;
• (iii) to apply said initial calibration function to said first ion mobility drift time data;
• (iv) to determine a first collision cross section of said one or more known or reference ions using said initial calibration function;
• (v) to compare said first collision cross section as determined using said initial calibration function with a known collision cross section of said one or more known or reference ions;
• (vi) to vary said initial calibration function to generate a revised calibration function, wherein a collision cross section of said one or more known or reference ions determined using said revised calibration function correlates more closely with said known collision cross section than said first collision cross section;
• (vii) to cause a second plurality of ions to be separated according to their ion mobility in said ion mobility spectrometer or separator and to acquire second ion mobility drift time data;
• (viii) to apply said revised calibration function to said second ion mobility drift time data;
• and
• (ix) to determine a collision cross section of said second ions using said revised calibration function.