WO2012167254A1 - Procédé et système de réduction des interférences dans l'analyse spectrométrique de stéroïdes - Google Patents

Procédé et système de réduction des interférences dans l'analyse spectrométrique de stéroïdes Download PDF

Info

Publication number
WO2012167254A1
WO2012167254A1 PCT/US2012/040748 US2012040748W WO2012167254A1 WO 2012167254 A1 WO2012167254 A1 WO 2012167254A1 US 2012040748 W US2012040748 W US 2012040748W WO 2012167254 A1 WO2012167254 A1 WO 2012167254A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
mobility spectrometer
differential mobility
curtain
providing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2012/040748
Other languages
English (en)
Inventor
Doina CARAIMAN
Yves Le Blanc
Hua-fen LIU
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DH Technologies Development Pte Ltd
Original Assignee
DH Technologies Development Pte Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DH Technologies Development Pte Ltd filed Critical DH Technologies Development Pte Ltd
Publication of WO2012167254A1 publication Critical patent/WO2012167254A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
    • G01N27/622—Ion mobility spectrometry
    • G01N27/624—Differential mobility spectrometry [DMS]; Field asymmetric-waveform ion mobility spectrometry [FAIMS]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/483—Physical analysis of biological material
    • G01N33/487—Physical analysis of biological material of liquid biological material
    • G01N33/49—Blood

Definitions

  • TITLE METHOD AND SYSTEM FOR REDUCING INTERFERENCES IN THE SPECTROMETRIC ANALYSIS OF STEROIDS
  • the present invention relates generally to methods and systems for reducing interferences in the spectrometric analysis of steroids. INTRODUCTION
  • interferences can be from non-steroid endogenous species from matrix and they can also be introduced by blood collection tubes.
  • Plasma and serum are common matrices used in clinical analysis, and they are typically collected using different types of blood collection tubes.
  • the tubes are usually filled with cloth activator as well as gel enabling faster and simpler separation of the plasma and serum from the red blood cells, and additional additives, such as heparin, can also be present in the tubes.
  • SST Serum Separation Tubes
  • PST Plasma Separation Tubes
  • MRM multiple reaction monitoring
  • the preparation of the sample can be modified
  • the LC conditions can be modified
  • an alternate blood sample collection tube can be used.
  • each of these current approaches can have drawbacks. For example, using a different MRM transition can lead to increased selectivity, but reduced sensitivity which can require starting with more samples.
  • modifying the LC conditions can lead to lower sample throughput resulting in longer delay times in supplying information to the requestor. The biggest challenge can be resolving interferences associated with the blood collection tube, especially if a specific test requires the use of a specific blood collection tube since it can impact the overall process.
  • protocol may be required to educate staff at the collection point, i.e., test for analyte x requires tube y; specific instrumentation may be required to separate plasma or serum from blood cells; it can require protocol to keep track of collection tubes used if pre-processed samples are to be re-analyzed; and physicians may need to be educated on all aspects associated with the special protocols to ensure proper assessment of the results obtained.
  • a system for reducing interferences in the spectrometric analysis of a sampie from a blood collection tube comprising an ion source for ionizing a sampie extracted from the blood collection tube, the sample containing one or more steroids.
  • the system comprises a differential mobility spectrometer for receiving the ions from the ion source, a boundary member defining a curtain gas chamber containing the differential mobility spectrometer; and a curtain gas supply for providing a curtain gas into an inlet of the differential mobility spectrometer for providing a gas flow through the differential mobility spectrometer and a curtain gas outflow out of a curtain gas chamber inlet.
  • the one or more steroids can comprise testosterone.
  • the system further comprises a mass spectrometer in fluid communication with the differential mobility spectrometer for receiving the ions from the differential mobility spectrometer.
  • the system further comprises a gas port having a gas outlet located between the differential mobility spectrometer and the mass spectrometer for drawing a gas outflow from the gas flow to modify the gas flow rate through the differential mobility spectrometer.
  • the f!ow rate of the gas outflow is varied to increase the gas flow rate.
  • the system comprises a vacuum chamber surrounding the mass spectrometer for maintaining the mass spectrometer at a vacuum pressure to draw the gas flow including the ions through the differential mobility spectrometer and into the vacuum chamber.
  • the system further comprises an electrical field generator for providing an electrical field between the differential mobility spectrometer and the vacuum chamber for guiding the ions into the vacuum chamber and to prevent ions from being drawn out of the gas outlet.
  • the differential mobility spectrometer comprises one of straight and curved electrodes.
  • the system further comprises at least one heater to heat at least one of the curtain gas, the gas outflow, a region upstream of the inlet of the differential mobility spectrometer, the inlet of the differential mobility spectrometer, and the inlet of the mass spectrometer.
  • the system further comprises a detector for detecting the ions received by the mass spectrometer.
  • the sample can be extracted from the blood collection tube by on-line extraction, protein precipitation, liquid-liquid extraction, or solid-phase extraction.
  • the sample can comprise plasma or serum.
  • the sample can be introduced into a liquid
  • chromatography apparatus comprising a column prior to ionization.
  • a method for reducing interferences in the spectrometric analysis of a sample from a blood collection tube.
  • the method comprises providing an ion source for ionizing a sample extracted from the blood collection tube, and the sample can contain one or more steroids.
  • the method further comprises providing a differential mobility spectrometer for receiving the ions from the ion source, providing a boundary member defining a curtain gas chamber containing the differential mobility spectrometer, and providing a curtain gas supply for providing a curtain gas into an inlet of the differential mobility spectrometer for providing a gas flow through the differential mobility spectrometer and a curtain gas outflow out of a curtain gas chamber inlet.
  • the one or more steroids can comprise testosterone.
  • a mass spectrometer can be in fluid communication with the differential mobility spectrometer for receiving the ions from the differential mobility spectrometer.
  • a gas outflow between the differential mobility spectrometer and the mass spectrometer can be drawn from the gas flow to modify the gas flow rate through the differential mobility spectrometer.
  • the flow rate of the gas outflow can be varied to increase the gas flow rate.
  • a vacuum chamber can surround the mass
  • the differential mobility spectrometer can comprise one of straight and curved electrodes.
  • at least one of the curtain gas, the gas outflow, a region upstream of the inlet of the differential mobility spectrometer, the inlet of the differential mobility spectrometer, and the inlet of the mass spectrometer can be heated.
  • the sample can comprise plasma or serum.
  • the method can further comprise introducing the extracted sample into a liquid
  • chromatography apparatus comprising a column prior to ionization.
  • a system for reducing interferences in the spectrometric analysis of steroids.
  • the system can comprise an ion source for ionizing a sample containing one or more steroids, a differential mobility spectrometer for receiving the ions from the ion source, a drift gas supply for providing a drift gas for flowing through the differential mobility spectrometer, and a modifier supply for supplying an actual volumetric flow rate of an organic acid modifier to the drift gas supply.
  • one or more steroids can comprise testosterone
  • the organic acid modifier can comprise formic acid.
  • the system can further comprise a meter for setting a seiected volumetric flow rate, and the actual volumetric flow rate can be within a percent deviation from the selected volumetric flow rate.
  • the system can further comprise a pump for supplying the actual volumetric flow rate of the modifier liquid to the drift gas supply.
  • the drift gas supply can be a curtain gas supply for providing a curtain gas
  • the spectrometer system can further comprise a boundary member for directing at least a portion of the curtain gas to an inlet of the differential mobi!ity spectrometer to become the drift gas.
  • the system can further comprise a curtain chamber for receiving the curtain gas with the added organic acid modifier, wherein the curtain chamber can comprise a curtain wall surrounding the differential mobility spectrometer, and the boundary member can be a portion of the curtain wall, !n various aspects, the drift gas supply can comprise a drift gas conduit, the modifier supply can comprise a modifier conduit, and the system can further comprises a junction for merging the modifier conduit into the drift gas conduit, and the pump can be located in the modifier conduit upstream of the junction to provide the actual volumetric flow rate of the modifier liquid to the drift gas conduit. In various embodiments, the system can further comprise a heater for heating the junction.
  • the system can further comprise a mass spectrometer in fluid communication with the differential mobility spectrometer for receiving the ions from the differential mobility spectrometer.
  • the system can further comprise a detector for detecting the ions received by the mass spectrometer.
  • the system can further comprise an electrical field generator for providing an electrical field between the differential mobility spectrometer and the vacuum chamber for guiding the ions into the vacuum chamber.
  • the differential mobility spectrometer can comprises straight or curved electrodes.
  • the system can further comprise a heater for heating the curtain chamber.
  • the sample can be introduced into a liquid chromatography apparatus comprising a column prior to ionization.
  • a method for reducing interferences in the spectrometric analysis of steroids.
  • the method comprises providing an ion source for ionizing a sample containing one or more steroids, providing a differential mobility spectrometer for receiving the ions from the ion source, providing a drift gas supply for providing a drift gas for flowing through the differential mobility spectrometer, and providing a modifier supply for supplying an actual volumetric flow rate of an organic acid modifier to the drift gas supply.
  • the one or more steroids can comprise testosterone.
  • the organic acid modifier can be formic acid.
  • the method can further comprise providing a meter for setting a selected volumetric flow rate, and the actual volumetric flow rate can be within a percent deviation from the selected volumetric flow rate.
  • the method further comprises providing a pump for supplying the actual volumetric flow rate of the modifier liquid to the drift gas supply.
  • the drift gas supply can be a curtain gas supply for providing a curtain gas, and a boundary member can be provided for directing at least a portion of the curtain gas to an inlet of the differential mobility spectrometer to become the drift gas.
  • a curtain chamber can be provided for receiving the curtain gas with the added organic acid modifier, wherein the curtain chamber comprises a curtain wall surrounding the differential mobility spectrometer, and the boundary member can be a portion of the curtain wall.
  • the drift gas supply comprises providing a drift gas conduit
  • the modifier supply comprises providing a modifier conduit
  • a junction can be provided for merging the modifier conduit into the drift gas conduit
  • the pump can be located in the modifier conduit upstream of the junction to provide the actual volumetric flow rate of the modifier liquid to the drift gas conduit.
  • the method can further comprise heating the junction, in various aspects, the method further comprises providing a mass spectrometer in fluid
  • the method further comprises detecting the ions received by the mass
  • the method further comprises providing an electrical field between the differential mobility spectrometer and the vacuum chamber for guiding the ions into the vacuum chamber.
  • the differential mobility spectrometer comprises straight or curved electrodes.
  • the method further comprises heating the curtain chamber.
  • the method further comprises introducing the sample into a liquid chromatography apparatus comprising a column prior to ionization.
  • Figure 1 schematically illustrates a differential mobility
  • Figure 2 schematically illustrates a differential mobility
  • Figure 3 schematically illustrates a differential mobility
  • Figure 4 schematically illustrates a differential mobility
  • Figure 4a shows the types of blood collection tubes that were evaluated.
  • Figure 5 shows interferences that are present in MS/MS spectra of a sample extracted from a blood collection tube.
  • Figure 6 shows interferences that are present in MS/MS spectra of a sample extracted from a blood collection tube.
  • Figure 7 shows parameter settings of the D MS-MS system according to various embodiments of the applicant's teachings.
  • Figure 7a shows the experimental conditions for Figures 8, 9, 10, and 1 1 according to various embodiments of the applicant's teachings.
  • Figure 8 compares the interferences present with the DMS off and with the DMS on according to various embodiments of the applicant's teachings.
  • Figure 9 compares the interferences present with the DMS off and with the DMS on according to various embodiments of the applicant's teachings.
  • Figure 10 compares the interferences present with the DMS off and with the DMS on according to various embodiments of the applicant's teachings.
  • Figure 1 1 compares the interferences present with the DMS off and with the DMS on according to various embodiments of the applicant's teachings.
  • Figures 1 1 a and 1 1 b show interferences from blood collection tubes and the shifting of testosterone from these interferences with the DMS on.
  • Figure 12 illustrates the shift in testosterone in the presence of formic acid according to various embodiments of the applicant's teachings.
  • Figure 13 shows a compensation voltage map displaying the shift in testosterone in the presence of formic acid according to various embodiments of the applicant's teachings.
  • Figure 14 shows a compensation voltage map displaying the shift in testosterone in the presence of formic acid according to various embodiments of the applicant's teachings.
  • Figure 15a compares the interferences present for a panel of steroids with the DMS off and with the DMS on according to various embodiments of the applicant's teachings.
  • Figure 15b lists the MRM monitored for the steroid panel
  • Figure 16a shows CoV regions for steroid and CoV region for noise introduced by the blood collection tube.
  • Figure 16b compares the interferences present for a panel of steroids with the DMS off and the DMS on at CoV 9.0 as representative of noise region for interferences introduced by the blood collection tube and CoV 4.5 for the steroid region.
  • Figure 17 shows the structure of some steroids.
  • Figure 18A shows the CoV shifting towards higher positive values as the SV is increased for testosterone when nitrogen is used as the transporter gas.
  • Figure 18B shows the CoV shift towards negative values as the SV is increased for testosterone when formic acid is used according to various embodiments of the applicant's teachings.
  • Figure 19 shows the CoV values for steroids according to various embodiments of the applicant's teachings.
  • Figure 20 shows the response for various steroids with the DMS off, DMS with no modifier, and DMS with formic acid.
  • Figure 21 shows the analysis of testosterone acquired in single MS mode with the DMS off, DMS with no modifier, and DMS with formic acid.
  • Figure 22 shows the analysis of testosterone acquired in MRM mode with the DMS off, DMS with no modifier, and DMS with formic acid.
  • Figure 23 shows the detection of isobaric steroids separated by DMS with formic acid according to various embodiments of the applicant's teachings.
  • Figures 24A and 24B show a 2-D view and a 3-D view of the detection of isobaric steroids separated by DMS with formic acid according to various embodiments of the applicant's teachings.
  • Figure 25 compares the interference caused by the injection of two isobaric steroids detected in MRM mode with the DMS off versus detection in SIM mode with DMS and formic acid.
  • FIG. 1 schematically illustrates a system 100 for reducing interferences in the spectrometric analysis of a sample from a blood collection tube in accordance with various embodiments of the applicant's teachings.
  • the system 100 comprises an ion source (not shown) that ionizes a sample, containing one or more steroids, extracted from a blood collection tube.
  • the blood collection tube can separate plasma and serum from the red blood cells in the sample.
  • a sample preparation process such as online solid-phase extraction, protein precipitation, liquid-liquid extraction, or solid-phase extraction can provide cleaner extracts prior to being introduced into a liquid chromatography apparatus comprising a column before ionization.
  • the differential mobility spectrometer (DMS) 102 can receive the ions from the ion source.
  • a boundary member 1 19 defining a curtain gas chamber 1 18 can contain the DMS 102.
  • a curtain gas supply 120 can provide a curtain gas into an inlet 1 10 of the DMS 102 for providing a gas flow through the DMS 102 and a curtain gas outflow 126 out of a curtain gas chamber inlet 122.
  • the one or more steroids comprises testosterone.
  • the system 100 further comprises a mass spectrometer (MS) 104 in fluid communication with the DMS 102 for receiving the ions from the DMS 102.
  • MS mass spectrometer
  • Mass spectrometer 104 can also comprise mass analyzer elements 104a downstream from vacuum chamber 127. Ions can be transported through vacuum chamber 127 and may be transported through one or more additional differentially pumped vacuum stages prior to the mass analyzer 104a. It will be apparent to those of skill in the art that there may be a number of other ion optica] elements in the system that have not been described.
  • the differential mobility spectrometer/mass spectrometer coupling described can be applicable to many mass spectrometer systems including, but not limited to, time of flight (TOF), ion trap, quadrupole, or other mass analyzers as known in the art.
  • TOF time of flight
  • the differential mobility spectrometer 102 comprises plates 106 and an electrical insulator 107 along the outside of plates 106.
  • the DMS 102 comprises straight or curved electrodes.
  • the plates 106 surround a drift gas 108 that drifts from an inlet 1 10 of the differential mobility spectrometer to an outlet 112 of the differential mobility spectrometer 102.
  • the insulator 107 supports the electrodes and isolates them from other conductive elements.
  • the outlet 212 of the DMS 102 is aligned with the inlet of the mass spectrometer 104 to define the ion path of travel between the DMS 102 and the mass
  • the differentia! mobility spectrometer 102 can be contained within a curtain chamber 1 18, defined by curtain plate (boundary member) 1 19 and supplied with a curtain gas from a curtain gas source 120.
  • the curtain gas source 120 provides the curtain gas to the interior of the curtain chamber 118.
  • ions 122 are provided from an ion source (not shown) and are emitted into the curtain chamber 1 18 via curtain chamber inlet 124.
  • the pressure of the curtain gas within the curtain chamber 1 18 provides both a curtain gas outflow 126 out of curtain gas chamber inlet 124, as well as a curtain gas inflow 128 into the differentia!
  • the curtain plate 119 may be connected to a power supply to provide an adjustable DC potential to it.
  • the mass spectrometer 104 is contained within a vacuum chamber 127, which can be maintained at a much lower pressure than the curtain chamber 1 8.
  • the vacuum chamber 127 can be maintained at a pressure of 2.3 Torr by a vacuum pump 130 while the curtain chamber 18 and an internal operating pressure of the differential mobility spectrometer 102 can be maintained at a pressure of 760 Torr.
  • the drift gas 108 is drawn through the differential mobility spectrometer 102, and, via vacuum chamber inlet 129, into the vacuum chamber 127.
  • the mass spectrometer 104 can be sealed to (or at least partially sealed), and in fluid communication with the differential mobility spectrometer to receive the ions 122 from the differential mobility
  • an electrical field can be provided between the DMS 102 and the vacuum chamber 127 for guiding the ions into the vacuum chamber.
  • the system can further comprise a detector for detecting the ions received by the mass spectrometer.
  • RF voltages can be applied across an ion transport chamber of a differential mobility spectrometer perpendicular to the direction of drift gas 108 (shown in Figure 1 ).
  • the RF voltages may be applied to one or both of the DMS electrodes comprising the differential mobility spectrometer.
  • the tendency of ions to migrate toward the walls and leave the path of the DMS can be corrected by a DC potential often referred to as a compensation voltage (CV).
  • the compensation voltage may be generated by applying DC potentials to one or both of the DMS electrodes comprising the differential mobility spectrometer.
  • a DMS voltage source (not shown) can be provided to provide both the RF SV and the DC CV.
  • multiple vo!tage sources may be provided.
  • at least one heater can be provided to heat at least one of the curtain gas, the gas outflow, a region upstream of the inlet of the differential mobility spectrometer, the inlet of the differential mobility spectrometer, and the in!et of the mass spectrometer.
  • FIG 2 there is schematic illustration of a system 300 in accordance with various embodiments of the applicant's teachings.
  • the same reference numerals used in Figure 1 with 200 added, are used in Figure 2 to designate elements analogous to the elements of Figure 1.
  • Figure 1 is not repeated with respect to Figure 2.
  • drift gas 308 can be drawn through the differential mobility spectrometer 302 and into the vacuum chamber 327 and the mass analyzer 304 by the much lower pressure maintained in the vacuum chamber 327.
  • the resolution or selectivity of system 300 can be adjusted by adding a throttle gas to a juncture chamber 314 between the differential mobility spectrometer 302 and the vacuum chamber inlet 329.
  • a throttle gas is provided for both the curtain gas and the throttle gas; however, separate sources may also be provided.
  • this gas could be nitrogen.
  • the throttle gas flows through a conduit branch 320a into the juncture chamber 314. The throttle gas throttles back the flow through the differential mobility spectrometer.
  • gas ports 332 are oriented or inclined such that the throttle gas flows into the juncture chamber 314 at an orientation that is toward the vacuum chamber 327 and away from the differentiai mobility spectrometer 302.
  • the gas ports 332 can be oriented such that the throttle gas flows along the sidewalls of the juncture chamber, somewhat parallel to the ion path of travel.
  • the juncture chamber can be designed with a much larger diameter than the diameter of the insulator, and the gas port can be oriented such that the gas stream through the inlet is directed along the wall.
  • Conduit branch 320a comprises a controllable valve 320b that can be used to control the rate of flow of the throttle gas into the juncture chamber 314.
  • the controllable valve 320b could be opened to admit more throttle gas into the juncture chamber 314 via conduit branch 320a to reduce the gas flow rate within the differential mobility spectrometer 302.
  • This can increase the residence time of the ions 322 within the differential mobility spectrometer.
  • the increased residence time can produce narrower mobility peak widths, and therefore, improved selectivity.
  • the increased residence time lowers sensitivity somewhat due to increased diffusion losses.
  • more of the ions can be lost.
  • Figure 2 also can comprise a valve 320c for controlling the rate of flow of the curtain gas into the curtain chamber 318.
  • the system can comprise a common gas supply to provide both the curtain gas and the throttle gas flows.
  • FIG 3 there is schematic illustration of a system 200 in accordance with various embodiments of the applicant's teachings.
  • the same reference numerals used in Figure 1 with 100 added, are used in Figure 2 to designate elements analogous to the elements of Figure 1.
  • Figure 1 is not repeated with respect to Figure 2.
  • the differential mobility spectrometer 202 is contained within a curtain chamber 218, defined by a curtain plate or boundary member 219, and supplied with a curtain gas from a curtain gas supply 220.
  • curtain gas from curtain gas supply 220 can flow through curtain gas conduit 220a at flow rates determined by flow controller 220b.
  • the system 200 also comprises a LC pump and organic acid modifier supply 214 for pumping precise amounts of an organic acid modifier liquid into the curtain gas conduit 220a at T-juncture 216.
  • LC pump 214 comprises a meter (not shown), which can be changed to set a selected volumetric flow rate of the modifier liquid into the juncture 216. Based on this adjustment of the meter, the LC pump 214 is then operable to provide an actual volumetric flow rate of the modifier liquid to the juncture 216 and into curtain gas conduit 220a to mix with the curtain gas.
  • LC pump 214 could be replaced with a syringe pump or other accurately controllable dispensing devices for dispensing the organic acid modifier liquid. Whatever dispensing device is used, this device can be sufficiently accurate such that the actual volumetric flow rate is within a relatively small percentage deviation of the selected volumetric flow rate.
  • FIG 4 there is schematically illustrated system 700 in accordance with various embodiments of the applicant's teachings.
  • the same reference numerals used in Figure 2, with 400 added, are used in Figure 6 to designate elements analogous to the elements of Figure 2.
  • Figure 6 For brevity the descriptions of preceding Figures are not repeated with respect to Figure 6.
  • a curtain gas supply 720 comprises a controllable valve 720b that can be used to control the rate of flow of the throttle gas into the juncture chamber 714 via conduit branch 720a.
  • Conduit or curtain gas supply 720 also comprises a valve 720c for controlling the rate of flow of the curtain gas that will ultimately end up in the curtain chamber 718.
  • the flow of the curtain gas downstream of valve 720c is divided into two branches 720d and 720e.
  • the flow of the curtain gas within branch 720d is controlied by valve 720f.
  • the flow of the curtain gas within branch 720e is controlled by valve 720g.
  • the flow of the curtain gas through branch 720d passes into a bubbler 720h, which can be used to add an organic acid modifier liquid to the curtain gas/drift gas, which passes.through branch 720d and will ultimately be pumped into the differential mobility spectrometer 702 by the vacuum maintained in the vacuum chamber 727.
  • a separate organic acid modifier can be added to the curtain gas flowing through branch 720e in bubbler 720i.
  • the curtain gas outflows from the bubblers 720h and 720i can be controlled by outlet valves 720j and 720k respectively, after which the two branches 720d and 720e merge and then release the curtain gas with the modifiers into the curtain chamber 718.
  • the curtain gas and drift gas are one and the same; thus, adding the organic acid modifier to the curtain gas adds simplicity to the system 700.
  • Organic acid modifiers can be vapors that provide selectivity by clustering with ions to different degrees, thereby shifting the differential mobility.
  • Examples of organic acid modifiers can include formic acid, any others to list?.
  • the applicant found unexpected results when adding formic acid as a modifier to a sample containing testosterone.
  • the formic acid modifier or additive to the drift gas shifted the observed compensation voltage for the testosterone peak at a given AC amplitude.
  • the compensation voltage is related to the ratio of high to low field mobility.
  • a bleed gas can be drawn from the gas flow between the differential mobility spectrometer and the mass spectrometer at a bleed gas flow rate to increase a gas flow rate through the differential mobility spectrometer.
  • the bleed gas flow rate can be varied to vary the increase in the gas flow rate. That is, in embodiments in which a bleed gas is drawn from the gas flow between the differential mobility spectrometer and the mass spectrometer, an electrode geometry of the differential mobility spectrometer can initially be selected to provide good selectivity at the price of poor or very poor sensitivity. Then, sensitivity can be improved, while selectivity is diminished, by increasing the bleed gas flow rate of the bleed gas drawn from the gas flow between the differential mobility spectrometer and the mass spectrometer.
  • Figure 4a shows the types of BD Vacutainer® blood collection tubes that were evaluated.
  • Figure 5 shows interferences that are present in MS/MS spectra of a sample extracted from a BD Vacutainer® PSTTM Gel and Lithium Heparin (green cap) blood collection tube.
  • the interferences generate signal as m/z 97 and 109 coinciding with the fragment ions of testosterone.
  • Figure 6 shows interferences that are present in MS/MS spectra of a sample extracted from a BD Vacutainer® SSTTM serum separation tube (gold cap). Two of the major interferences generate signal at m/z 97 and 109 coinciding with the fragment ions of testosterone.
  • Figure 7 shows parameter settings of the DMS-MS system according to various embodiments of the applicant's teachings.
  • Figure 7a shows the experimental conditions for Figures 8, 9, 10, and 1 1.
  • Figures 8, 9, 10, and 1 1 compare the interferences present in testosterone plasma samples with the D S off and with the D S on according to various embodiments of the applicant's teachings. Interferences from the blood collection tube are reduced when the DMS is on. The expected fragment ion ratio between MRM 289-109 and 289-97 is only observed when data is collected with the DMS on.
  • Figures 1 1 a and 1 1 b show that the BD Vacutainer® PSTTM and
  • SSTTM blood collection tubes can contribute to interferences in the analysis of testosterone and the shifting of testosterone from these interferences with the DMS on.
  • Figure 12 illustrates the compensation voltage (CV) shift for testosterone in the presence of formic acid according to various embodiments of the applicant's teachings.
  • the shift enables testosterone to be
  • Figure 13 shows a compensation voltage map displaying the shift for testosterone in the presence of formic acid according to various embodiments of the applicant's teachings.
  • the CV for the three interferences shifted to positive values at a separation voltage (SV) of 3200 while testosterone shifted to a negative value at SV of 3200 using SIM mode with formic acid as a dopant (1.5% in curtain gas) enabling testosterone to be discernible from the interferences.
  • SV separation voltage
  • Figure 14 shows a compensation voltage map displaying the shift in testosterone in the presence of formic acid in a urine sample according to various embodiments of the applicant's teachings.
  • the interferences shift to a positive CV while testosterone shifts to a negative CV enabling testosterone to be distinguished from the interferences.
  • Figure 15a compares the interferences present for a panel of steroid (10 steroids, 21 MRM pairs - list supplied in Figure 15b) extracted from pooled female and male plasma protein precipitated (PPT) that was obtained from BD Vacutainer® SSTTM (Gold Cap) with the D S off and with the DMS on according to various embodiments of the applicant's teachings.
  • PPT plasma protein precipitated
  • Figure 16b shows the TIC for the steroid panel (from Figure 15b) extracted from pooled female and male plasma protein precipitated (PPT) that was obtained from BD Vacutainer® SSTTM (Gold Cap) with the DMS off (top panel), the DMS on at CoV 9.0 as representative of the chemical noise introduced from the blood collection tube (middle panel), and the DMS on at CoV 4.5 as representative region of steroid panel (bottom panel).
  • PPT pooled female and male plasma protein precipitated
  • a sample, containing one or more steroids, from a blood collection tube can be extracted using techniques, such as on-line extraction, protein precipitation, liquid-liquid extraction, or solid-phase extraction, as known in the art.
  • the one or more steroids in the sample can comprise testosterone.
  • the sample can comprise plasma or serum.
  • the extracted sample can be introduced into a liquid chromatography apparatus comprising a column prior to ionization of the sample. An ion source can then ionize the sample and a DMS can receive the ions from the ion source.
  • a boundary member defining a curtain gas chamber containing the DMS can be provided.
  • a curtain gas provided from a curtain gas supply can enter into an inlet of the DMS to provide a gas flow through the DMS and a curtain gas outflow out of a curtain gas chamber inlet.
  • a mass spectrometer can be in fluid communication with the differential mobility spectrometer for receiving the ions from the differential mobility spectrometer.
  • a gas outflow between the differential mobility spectrometer and the mass spectrometer can be drawn from the gas flow to modify the gas flow rate through the differentia! mobility spectrometer. The flow rate of the gas outflow can be varied to increase the gas flow rate.
  • a vacuum chamber can surround the mass spectrometer for maintaining the mass spectrometer at a vacuum pressure to draw the gas flow including the ions through the differential mobility spectrometer and into the vacuum chamber.
  • An electrical field can be provided between the differential mobility spectrometer and the vacuum chamber for guiding the ions into the vacuum chamber and to prevent ions from being drawn out of the gas outlet.
  • the differential mobility spectrometer can comprise one of straight and curved electrodes. At least one of the curtain gas, the gas outflow, a region upstream of the inlet of the differential mobility spectrometer, the inlet of the differential mobility spectrometer, and the inlet of the mass spectrometer can be heated.
  • a sample can be introduced into a liquid chromatography apparatus comprising a column prior to ionization.
  • An ion source is provided for ionizing a sample containing one or more steroids.
  • a differential mobility spectrometer is provided for receiving the ions from the ion source and a drift gas supply is provided for providing a drift gas for flowing through the differential mobility spectrometer, and an organic acid modifier supply can be provided for supplying an actual volumetric flow rate of an organic acid modifier to the drift gas supply.
  • the one or more steroids can comprise testosterone.
  • the organic acid modifier can be formic acid.
  • a meter can be provided for setting a selected volumetric flow rate, and the actual volumetric flow rate can be within a percent deviation from the selected volumetric flow rate.
  • a pump can be provided for supplying the actual volumetric flow rate of the modifier liquid to the drift gas supply.
  • the drift gas supply can be a curtain gas supply for providing a curtain gas, and a boundary member can be provided for directing at least a portion of the curtain gas to an inlet of the differential mobility spectrometer to become the drift gas.
  • a curtain chamber can be provided for receiving the curtain gas with the added organic acid modifier, wherein the curtain chamber comprises a curtain wall surrounding the differential mobility spectrometer, and the boundary member can be a portion of the curtain wail.
  • the drift gas supply comprises providing a drift gas conduit
  • the organic acid modifier supply comprises providing a modifier conduit
  • a junction can be provided for merging the modifier conduit into the drift gas conduit
  • the pump can be located in the modifier conduit upstream of the junction to provide the actual volumetric flow rate of the modifier liquid to the drift gas conduit.
  • the junction can be heated.
  • a mass spectrometer can be in fluid communication with the differential mobility spectrometer for receiving the ions from the differential mobiiity spectrometer.
  • a detector can detect the ions received by the mass spectrometer.
  • An electrical field can be provided between the differential mobility spectrometer and the vacuum chamber for guiding the ions into the vacuum chamber.
  • the differential mobility spectrometer can comprise straight or curved electrodes.
  • the curtain chamber can be heated.
  • HPLC Conditions LC was performed using a Shimadzu Prominence UFLC system operated at 400ulJmin using a gradient from 90% of mobile phase A (water/aceto nit rile (95/5 (v/v)) + 0.1 % formic acid) to 80% of B (water/acetonitrile (5/95 (v/v)) + 0.1% formic acid) over 5 minutes.
  • the column oven was operated at 40oC.
  • Two types of HPLC columns were used; 1 ) Luna Kinetex C18 (2x50mm, 2.6u) from Phenomenex (Torrance, CA) and 2) BDS Hypersii Gold (2x50mm, 3u) from Thermo (Ottawa, ON).
  • the injection volume was 10uL
  • the SelexlONTM Technology is a planar differential mobility separation (DMS) device that attaches between the curtain plate and orifice plate of the 5500 QTRAP® system. Gas draws the ions towards the orifice while an asymmetric waveform applied to the flat plates, which alternates between high field, K(E) and low field, K(0). This moves the charged ion back and forth between plates; an ion will have net drift base on its high and low field mobility. Finally a compensation voltage (CoV, a small DC offset between the plates) is applied at a filtering voltage which is specific for each ion being targeted.
  • the chemical modifier is introduced with a liquid pump directly into the curtain gas stream. Formic acid was introduced directly into the gas stream, and the Turbo V® source was operated with the electrospray ionization (ESI) probe and the source was operated at 650°C with Gas 1 and Gas 2 at 40 and 80 psi, respectively.
  • ESI electrospray ionization
  • Figure 17 shows the structure of some of steroids used. These were selected to cover a variety of structural features typically encountered in steroids. In all cases, a CoV mapping/optimization was performed under analytical conditions either by using a split-infusion approach post-LC or by injecting on-column and performing monitoring at multiple CoV values (typically ranging from -20 to 20 with increments of 1 ,25V).
  • Figure 18A shows the CoV shifting towards higher positive values as the SV is increased to 3500V when nitrogen is used as the transporter gas. When the transport gas is doped with .5% (v/v) with formic acid, the CoV shift towards negative values under similar conditions (Figure 18B).
  • Figure 21 shows the relative selectivity when the detection testosterone from protein precipitated plasma is performed by single ion monitoring (SIM) in 3 modes of operation for the DMS cell: 1 ) all DMS voltages turned off, 2) DMS with no chemical modifier and 3) DMS with formic acid in transport gas.
  • Figure 22 shows the relative selectivity when the detection testosterone from protein precipitated plasma is performed in multiple reaction monitoring (MRM) mode in 3 modes of operation for the DMS cell: 1 ) all DMS voltages turned off, 2) DMS with no chemical modifier and 3) DMS with formic acid in transport gas.
  • MRM multiple reaction monitoring
  • FIG. 14 shows similar observation when a diluted urine sample is analyzed with formic acid in the transport gas. Again, the majority of the endogenous species that are isobaric (m/z 289) have a positive CoV values, where as testosterone has a negative CoV value.
  • Figures 23 and 24 show the CoV map associated with detection of andrsotenedione and 1 - dehydrotestosterone in SIM mode.
  • Figure 24A shows a 2-D view and
  • Figure 24B shows a 3-D view of the same data.
  • Both analytes have unique CoV values with little overlap, thus enabling selective detection even in SIM mode. Though both have unique dominant MRM fragments to ensure selectivity, this was used as a case to compare the selectivity of DMS-SIM with formic acid.
  • Figure 25 shows that DMS-SIM with formic acid gives a level of selectivity that is comparable to MRM alone as similar levels of interference were observed when equimolar levels were indicated. This can emphasize the reliance on the LC separation if using DMS-SIM with formic acid or alternatively relax the LC separation and combine DMS-MRM with formic acid which can obtain ultimate selectivity.
  • the addition of formic acid to the transport gas of a DMS cell can show benefit for the analyses of steroids.
  • the steroids can preferentially shift toward negative CoV values when many other endogenous species seem to be essentially unaffected by the presence of formic acid and their CoV typically stay positive.
  • the addition of formic acid may reduce the signal intensity by 20-50% when compared to no modifier added in the transport cell, this approach can offer the ability to detect the steroid with a degree of selectivity with SIM detection that can rival MRM detection.
  • the exact nature of the interaction between formic acid and the steroids in the DMS cell can be complex, but it is clearly unique and it can be likely associated with the site of protonation of the analyte.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Biomedical Technology (AREA)
  • Biochemistry (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Analytical Chemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Hematology (AREA)
  • Ecology (AREA)
  • Electrochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biophysics (AREA)
  • Molecular Biology (AREA)
  • Urology & Nephrology (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)

Abstract

L'invention concerne un système et un procédé permettant de réduire des interférences dans l'analyse spectrométrique d'un échantillon d'un tube de collecte de sang comprenant une source ionique destinée à ioniser un échantillon extrait du tube de collecte de sang, l'échantillon contenant au moins un stéroïde. Le système comprend un spectromètre à mobilité différentielle pour recevoir les ions provenant d'une source ionique, un élément de délimitation définissant une chambre de rideau de gaz contenant le spectromètre à mobilité différentielle; et une alimentation de rideau de gaz pour fournir un gaz de rideau dans une admission du spectromètre à mobilité différentielle pour fournir un flux de gaz traversant ledit spectromètre à mobilité différentielle et une sortie de gaz de rideau d'une admission de chambre de rideau de gaz. L'invention concerne en outre un système et un procédé permettant de fournir une alimentation de modification qui fournit un débit volumétrique réel d'un modificateur d'acide organique à une alimentation en gaz de dérive pour réduire des interférences.
PCT/US2012/040748 2011-06-03 2012-06-04 Procédé et système de réduction des interférences dans l'analyse spectrométrique de stéroïdes Ceased WO2012167254A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201161493211P 2011-06-03 2011-06-03
US61/493,211 2011-06-03

Publications (1)

Publication Number Publication Date
WO2012167254A1 true WO2012167254A1 (fr) 2012-12-06

Family

ID=47259957

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2012/040748 Ceased WO2012167254A1 (fr) 2011-06-03 2012-06-04 Procédé et système de réduction des interférences dans l'analyse spectrométrique de stéroïdes

Country Status (1)

Country Link
WO (1) WO2012167254A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9500624B2 (en) 2014-06-13 2016-11-22 Thermo Finnigan Llc System comprising a mass spectrometer coupled to a FAIMS apparatus and methods of operation
WO2021209905A1 (fr) * 2020-04-13 2021-10-21 Dh Technologies Development Pte. Ltd. Systèmes et procédés de régulation de gradient de température avec un spectromètre de mobilité différentielle
WO2022269517A1 (fr) * 2021-06-22 2022-12-29 Dh Technologies Development Pte. Ltd. Systèmes et procédés automatisés de séparation de composés

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6703609B2 (en) * 2000-03-14 2004-03-09 National Research Council Canada Tandem FAIMS/ion-trapping apparatus and method
US20060255261A1 (en) * 2005-04-04 2006-11-16 Craig Whitehouse Atmospheric pressure ion source for mass spectrometry
US20080166697A1 (en) * 2003-09-08 2008-07-10 Quest Diagnostics Investments Incorporated Determination of testosterone by mass spectrometry
US20090256073A1 (en) * 2006-02-07 2009-10-15 Mds Inc. Chemical Noise Reduction For Mass Spectrometry
US20100282966A1 (en) * 2008-05-30 2010-11-11 DH Technologies Development Pte Ltd. Method and system for vacuum driven mass spectrometer interface with adjustable resolution and selectivity
US20110183431A1 (en) * 2010-01-28 2011-07-28 MDS Analytical Technologies, a business unit of MDS, Inc. Mass analysis system with low pressure differential mobility spectrometer

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6703609B2 (en) * 2000-03-14 2004-03-09 National Research Council Canada Tandem FAIMS/ion-trapping apparatus and method
US20080166697A1 (en) * 2003-09-08 2008-07-10 Quest Diagnostics Investments Incorporated Determination of testosterone by mass spectrometry
US20060255261A1 (en) * 2005-04-04 2006-11-16 Craig Whitehouse Atmospheric pressure ion source for mass spectrometry
US20090256073A1 (en) * 2006-02-07 2009-10-15 Mds Inc. Chemical Noise Reduction For Mass Spectrometry
US20100282966A1 (en) * 2008-05-30 2010-11-11 DH Technologies Development Pte Ltd. Method and system for vacuum driven mass spectrometer interface with adjustable resolution and selectivity
US20110183431A1 (en) * 2010-01-28 2011-07-28 MDS Analytical Technologies, a business unit of MDS, Inc. Mass analysis system with low pressure differential mobility spectrometer

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9500624B2 (en) 2014-06-13 2016-11-22 Thermo Finnigan Llc System comprising a mass spectrometer coupled to a FAIMS apparatus and methods of operation
WO2021209905A1 (fr) * 2020-04-13 2021-10-21 Dh Technologies Development Pte. Ltd. Systèmes et procédés de régulation de gradient de température avec un spectromètre de mobilité différentielle
US12498351B2 (en) 2020-04-13 2025-12-16 Dh Technologies Development Pte. Ltd. Systems and methods for controlling temperature gradient along a differential mobility spectrometer
WO2022269517A1 (fr) * 2021-06-22 2022-12-29 Dh Technologies Development Pte. Ltd. Systèmes et procédés automatisés de séparation de composés
US20240282564A1 (en) * 2021-06-22 2024-08-22 Dh Technologies Development Pte. Ltd. Automated systems and methods for separating compounds

Similar Documents

Publication Publication Date Title
EP2281297B1 (fr) Procédé et système pour interface spectromètre de masse/spectromètre de mobilité différentielle actionnée par la dépression avec résolution et sélectivité ajustables
CN106526026B (zh) 血清中25-羟基维生素d的检测方法
CN104364641B (zh) 血清及其它生物基质中的分析物的量化
EP2850424B1 (fr) Procédés pour la détection sélective d'acides biologiquement pertinents
EP3186625B1 (fr) Méthodes de séparation des peptides dans un spectromètre à mobilité différentielle utilisant un complexe peptide-métal alcalino-terreux
US20150260684A1 (en) Method and apparatus for ion mobility spectrometry
US20250251362A1 (en) Liquid chromatography- mass spectrometry (lc-ms) methods for analyzing ampholyte lot variation
US11226310B2 (en) Controlling gas-phase ion interactions
US9164060B2 (en) Reducing interferences in isobaric tag-based quantification
CN105340053A (zh) 双极性火花离子源
US9846143B2 (en) Ion mobility method and apparatus
WO2012167254A1 (fr) Procédé et système de réduction des interférences dans l'analyse spectrométrique de stéroïdes
Zhang et al. Rapid screening and quantification of glucocorticoids in essential oils using direct analysis in real time mass spectrometry
US10607827B2 (en) Method and apparatus for the chemical ionization of samples
CN115104027A (zh) 用于通过差分迁移谱测定法分离相似质量的化合物的系统和方法
Hao et al. On-line pre-treatment, separation, and nanoelectrospray mass spectrometric determinations for pesticide metabolites and peptides based on a modular microfluidic platform
EP4244611A1 (fr) Procédé de détection de stéroïdes isomériques à l'aide d'une spectrométrie de mobilité différentielle
EP3047506A1 (fr) Réglage automatique de tension capillaire en fonction des conditions d'élution pour maintenir optimale des conditions d'ionisation
Deepan et al. Chapter-2 Instrumentation & Extraction Techniques of LC
Marwah et al. Ion funnel quadrupole time of Flight mass spectrometry: optimization for achieving all ion MS/MS and pseudo MSn

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12792896

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12792896

Country of ref document: EP

Kind code of ref document: A1