LCMS - Ion Optics Path and Parameters.pptx
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The document outlines the ion optics path and parameters crucial for mass spectrometry, detailing components and their respective parameters such as the orifice plate, q jet ion guide, quadrupoles, and collision cell. Each parameter is described with its function, optimization techniques, and how it impacts analysis effectiveness for different compounds. Key parameters include source and gas settings, compound-dependent voltages, and detector responses essential for achieving optimal instrument performance.
LCMS - Ion Optics Path and Parameters.pptx
- 1. LCMS - Ion Optics Path and Parameters C. P.Singh
- 2. Ion Optics Path and Parameters 1. Orifice plate 2. Q Jet ion guide 3. Q0 region 4. Q1 quadrupole 5. Q2 collision cell 6. Q3 quadrupole 7. Detector
- 3. Parameters Source and gas parameters: These parameters can change depending on the ion source used. Compound parameters: These parameters consist mostly of voltages in the ion path. Optimal values for compound- dependent parameters vary depending on the compound being analyzed. Resolution parameters: These parameters affect the resolution and calibration. Detector parameters: These parameters affect the detector. The working parameters are the set of mass spectrometer parameters currently being used. The compound parameters and source and gas parameters are stored with the method. The resolution and detector parameters are mass spectrometer- dependent and are stored as instrument data. If the Tune and Calibrate mode is used to create a method, then the working parameters can be optimized for best instrument performance. Alternatively, ramp each parameter, one at a time, while cycling the experiment.
- 4. Location Parameter Parameter Type Use Scan Type 1 IonSpray Voltage (IS) Source and Gas The IS parameter controls the voltage applied to the electrode in the turbolon spray probe that ionizes the sample in the ion source. The parameter depends on the polarity and it affects the spray stability and the sensitivity. The parameter can be compound depended and must be optimized for each compound. All 1 Nebulizer Current (NC) Source and Gas The NC parameter controls the current applied to the corona discharge needle in the APCI probe, used in the Turbo VTM Ion Source. The discharge ionizes solvent molecules, which in turn ionize the sample molecules. All 1 Ion Source Gas 1 (GS1) Source and Gas For the Turbo VTM ion source, the GS1 parameter controls the nebulizer gas for both the Turbolon Spray and APCI probes. All 1 Ion Source Gas 2 (GS2) Source and Gas For the Turbo VTM ion source, the GS2 parameter controls the heater gas for the Turbolon Spray probe. All 1. Orifice plate
- 5. Location Parameter Parameter Type Use Scan Type 1 Temperature (TEM) Source and gas The TEM parameter controls the temperature of the heater gas for the Turbolon Spray Probe or the temperature of the APCI probe. All 1 Curtain Gas (CUR) Source and Gas The CUR parameter controls the gas flow of the curtain GasTM interface. The Curtain GasTM interference is located between the curtain plate and the orifice. It prevents the contamination of the ion optics. All 1 Delustering Potential (DP) Compound The DP parameter controls the voltage on the orifice, which controls the ability to decluster ions between the orifice and the Ion Drive Qjet ion guide. It is used to minimized the solvent cluster that might remain on the sample ions after they enter the vacuum chamber, and if required, to fragment ions. The higher the voltage the energy impared to the ions. If the DP parameters is too high, then unwanted fragmentation might occur. Use the preset value and optimize for the compound. All 1. Orifice plate
- 6. Location Parameter Parameter Type Use Scan Type 2 Entrance Compound Potential (EP) Compound The EP parameter controls the potential difference between the voltage on Q0 and ground. The entrance potential guides and focuses the ions through the high-pressure on the Q0 region. Use the preset value. All 2 Q0 Trapping Compound The Q0 trapping parameter controls the storage of ions in the Q0 region. It is used to increase sensitivity and duty cycle by trapping ions in the Q0 region while ions are being mass-selectively ejected from the linear ion trap. Use a fixed fill time with this parameter. Either select or clear the feature as required by the experiment. Use a fixed fill time of 20 ms or gretter. EMS, EMC, EPI, ER, and MS/MS/MS 2. Q Jet ion guide
- 7. Location Parameter Parameter Type Use Scan Type 3 CAD Gas Source and gas The CAD parameter controls the pressure of the CAD gas in the collision cell during Q3, MS/MS and LIT scans. For Q3 scan, the collision gas helps to focus the ions as they pass through the Q2 collision cell. The pre-set value for the CAD parameters is in fixed mode. For MS/MS scan types, the CAD gas helps to fragment the precursor ions. When the precursor ions collide with the collision gas, they dissociate to form product ions. For LIT scan types, the collision gas helps to focus and trap ions in the linear ion trap. Use the pre-set value and optimize for the compound. Q3 MI, Q3MS, MRM, Prec, NL, EMS, ER, EPI, MS/MS/MS EMC and TDF 1. Orifice plate 2. Q Jet ion guide 3. Q0 region 4. Q1 quadrupole 5. Q2 collision cell 6. Q3 quadrupole 7. Detector
- 8. Location Parameter Parameter Type Use Scan Type 3 Collision Energy (CE) Compound The CE parameter controls the potential difference between the Q0 region and the Q2 collision cell. It is used only in MS/MS scan types. This parameter is the amount of energy that the precursor ions receive as they are accelerated into the Q2 collision cell, where they collide with gas molecules and fragment. Use the preset value and optimize for the compound. EPI, MS/MS/ MS, MRM, MS2, Prec, NL, and LIT 3 Collision Energy Spread (CES) Compound The CES parameter, in conjunction with the CE parameter, determines which three discrete collision energies are applied to the precursor mass in an Enhanced Product Ion (EPI) or MS/MS/MS (MS3) scan when CES is used. When a collision energy spread value is entered, CES is automatically turned on. Use the preset value and optimize for the compound. EPI and MS/MS/MS 3 Collision Cell Exit Potential (CXP) Compound The CXP parameter is only used in Q3 and MS/MS scan types. This parameter transmits the ions into the Q3 quadrupole. Use the preset value and optimize for the compound. Q3, MRM, MS2, Prec, NL
- 9. Location Parameter Parameter Type Use Scan Type 4 Q3 Entry Barrier Compound The Q3 Entry Barrier parameter is used to transfer the ions from the Q2 collision cell into the linear ion trap. Use the preset value. EMS, EMC, EPI, ER, and MS/MS/MS 4 Q3 Empty Time Compound The Q3 Empty Time parameter controls the EMC amount of time that elapses before singly-charged ions are removed from the linear ion trap. Use the preset value. EMC 1. Orifice plate 2. Q Jet ion guide 3. Q0 region 4. Q1 quadrupole 5. Q2 collision cell 6. Q3 quadrupole 7. Detector
- 10. Location Parameter Parameter Type Use Scan Type 5 Multi-Charge Separation (MCS) Barrier Compound The MCS Barrier parameter controls the voltage EMC used to eliminate the singly-charged ions from the linear ion trap. Use the preset value. EMC 5 MS/MS/MS Fragmentation Excitation Time Compound The MS/MS/MS Fragmentation Time parameter MS/MS/MS controls the amount of time that the excitation energy is applied. It is used in combination with the excitation energy to fragment the isolated second precursor ion. Use the preset value. MS/MS/MS 1. Orifice plate 2. Q Jet ion guide 3. Q0 region 4. Q1 quadrupole 5. Q2 collision cell 6. Q3 quadrupole 7. Detector
- 11. Location Parameter Parameter Type Use Scan Type 6 Fixed LIT Fill Time Compound The Fixed LIT Fill Time parameter controls the amount of time that the LIT fills with ions. Use the preset value and adjust it to achieve the desired signal response based on sample concentration. MS/MS/MS Compound Fragmentati on Excitation Time 6 Dynamic Fill Time (DFT) Compound The DFT parameter dynamically calculates the amount of time that ions are collected in the linear ion trap based on the incoming ion signal. When DFT is turned on, the signal is optimized to either increase sensitivity or minimize space-charging. Either select or clear the feature based on the experiment. In the Tools > Settings > Method Options dialog, the DFT settings are optimized for the default scan rate. These settings are also suitable for other LIT scan speeds. EMS, EPI, ER, and MS/MS/ MS 7 CEM Detector The CEM parameter controls the voltage applied All to the detector. The voltage controls the detector response. All 6. Q3 quadrupole 7. Detector
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