JPH06508469A - Mass spectrometry using supplemental alternating voltage signals - Google Patents

Abstract

A mass spectrometry method in which one or more high power supplemental AC voltage signals and one or more low power supplemental AC voltage signals are applied to an ion trap (16). The frequency of each supplemental AC voltage is selected to match a resonance frequency of an ion having a desired mass-to-charge ratio. The low power supplemental voltage signals are applied for the purpose of dissociating specific ions (i.e., parent ions) within the trap, and the high power supplemental voltage signals are applied to resonate products of the dissociation process (i.e., daughter ions) so that they can be detected. In one class of embodiments, the high power voltage signals resonate daughter ions out from the trap for detection by an external detector (24). In another class of embodiments, each high power voltage signal resonates the daughter ions only to a degree sufficient for detection by an in-trap detector (which may comprise one or more of the electrodes (11-13) which define the trapping field, or may be mounted integrally with such electrodes).

Description

[Detailed description of the invention] Mass spectrometry using supplemental alternating voltage signals Technical field The present invention dissociates parent ions in an ion trap and causes the resulting daughter ions to resonate. Concerning mass spectrometry that enables detection. More specifically, the present invention provides supplementary An alternating current voltage signal is applied to the ion trap to dissociate the parent ions in the trap; It is a mass spectrometry method that uses resonance to detect the resulting daughter ions.

Background technology In one class of conventional mass spectrometry techniques, known as MS/'MS methods, the selection The parent ion has a mass-to-charge ratio within the specified range. ] ions are isolated in an ion trap. Then captured parent ions (e.g., by colliding with background gas molecules in the trap) ) J This produces ions known as ions. After that, the daughter Aeon was released from the tiger whelk. Detect.

For example, Syka et al., effective April 5, 1988.

et al., in U.S. Patent No. 4.736.101 to ions (having mass-to-charge ratios within a certain range) in a three-dimensional quadrupole trapping field. An MS/MS method for capturing is disclosed. Then scan the acquisition field to remove unwanted parent ions (ions other than the parent ion with the desired mass-to-charge ratio). The traps are released one after another. Then change the capture field again to target daughter Allows ions to be stored. The captured parent ions are then dissociated to form daughter ions. daughter ions are successively released from the trap for detection.

In order to release unwanted parent ions from the trap prior to parent ion dissociation, U.S. Pat. No. 4,736,101 describes the acquisition field as It teaches that scanning should be done by sweeping the amplitude of a specified fundamental voltage. Ru.

U.S. Pat. No. 4,736,101 also describes a phase in which the parent ion is dissociated. (see column 5, lines 43 to 62 for this). ) or the ejected ions can be used for subsequent ejections of sample ions and so that it is not detected during detection (this is done from column 4, line 60 to column 5, line 6). Supplemental AC feeds can be used to release specific ions from the trap. It also teaches that a voltage can be applied.

U.S. Pat. No. 4.736.101 also describes the supplemental AC field as other ions of interest (only a small amount) by applying them to the trap during the initial ionization period Certain ions that may interfere with the study of It also suggests that it can release ions (which would otherwise exist in large quantities). (See column 5 between lines 7 and 12 for this).

However, in the conventional M/M S method, a limited range is required for each target sample. Only surrounding information can be obtained. Samples can be acquired using conventional MS/MS methods. It is desirable to acquire a wider range of information than information. to analyze the sample To minimize the time required and to maximize information about the sample This information is obtained by selectively resonating target daughter ions for detection. It is also desirable to do so. However, until the present invention, this was not possible in the ion trap. It was unknown how all of their goals would be achieved.

Summary of the invention The present invention provides at least one powerful (selected ion) capable of detecting ions. (having strong power in the sense that the amplitude is sufficient to cause resonance to a certain extent) An alternating current voltage signal is applied to the ion trap, with at least one weak (amplitude is sufficient to induce dissociation of selected ions, but Weak power in the sense that it is insufficient to cause it to resonate to the extent that it can be detected. This is a mass spectrometry method in which a supplemental alternating current voltage signal (with a ion trap) is also applied to the ion trap.

The frequency of the supplemental alternating voltage signal is the resonant frequency of ions with the desired mass-to-charge ratio. selected to match the number.

Each of the weak complementary alternating voltage signals is associated with a specific ion within the trap (i.e., the parent ion). ), and a strong complementary alternating voltage signal is applied with the purpose of dissociating the dissociation process ( The result of the dissociation process is made to resonate so that the daughter ions) can be detected. added.

In one type of embodiment, daughter ions are detected by a strong alternating voltage signal. caused to resonate from the trap by an external detector. ion trap detection In another type of embodiment using a device, each of the strong alternating voltage signals is The in-trap detector (defines the capture field) to a sufficient degree for detection within the trap. consisting of one or more electrodes, or integrated with such electrodes. All that is required is to cause the daughter ions to resonate by the ion (which is attached jointly).

Brief description of the drawing FIG. 1 is a simplified illustration of an apparatus useful for carrying out the preferred embodiment type of the invention. This is a conceptual diagram.

FIG. 2 is a diagram representing the signals generated during operation of the first preferred embodiment of the invention. It is.

FIG. 3 is a diagram representing the signals generated during operation of the second preferred embodiment of the invention. It is.

FIG. 4 is a diagram representing the signals generated during operation of the third preferred embodiment of the invention. It is.

Preferred form for carrying out the invention The quadrupole ion trap device shown in FIG. 1 is of the type of preferred embodiment of the present invention. Useful for implementing one. The device of FIG. 1 includes an annular electrode 11 and an end electrode 1. 2 and 13 are included. The three-dimensional quadrupole capture field is generated by the basic voltage generator 14 is turned on and a fundamental high frequency voltage (high frequency wave components and optionally also a direct current) is applied to the electrodes 11 to 13. is generated in an area 16 surrounded by. The ion storage area 16 has a radius ro and a vertical dimension Zo. Electrodes 11, 12, and 13 are combined voltage transformers. They are commonly grounded through a device 32.

By switching on the supplemental alternating current voltage generator 35, the desired supplementary alternating current voltage is generated. A pressure signal can be applied across end electrodes 12 and 13. Supplementary AC voltage signal The signal is used to make the trapped desired ions resonate at the axial resonant frequency (described below). (as described in detail).

When the filament 17 is heated by the filament power supply 18, this causes the An energizing electron beam is directed through an opening in end electrode 12 to area 16 . electronic video The sample molecule in zone 16 is ionized by the beam and the resulting ions are transferred to the quadrupole. Capture within area 16 can be achieved by a child capture field. cylindrical gate electrode The poles and lenses 19 are controlled by a filament lens control circuit 21, which The gate opens and closes the electron beam as desired.

In one embodiment, the end electrode 13 includes an electron multiplier tube detector 24 with ions placed therein. perforation 23 through which it is emitted from area 16 for detection by is provided. The electric meter 27 receives the current signal collected at the output of the detector 24. The signal is received and converted into a voltage signal for processing within processor 29. voltage signal The numbers are summed and stored in circuit 28.

In a variant of the device of Figure 1, the perforations 23 are omitted and the Replaced by ion detector. Such in-trap detectors are located at the trap electrodes. It can be configured by itself. For example, one or both of the end electrodes (one of the electrodes (or (or partially configured). In another type of embodiment, The in-trap ion detector is clearly distinguished from the end electrodes, but the in-trap ion detector is on both sides (the ions impacting the end electrodes are significantly influenced by the shape of the end electrode surface facing area 16). integrally mounted so as to detect without introducing significant distortion). This format One example of an in-trap ion detector is an electrically insulated conductive pin tipped with the end flush with the surface of the end electrode (preferably along the Z-axis at the center of the end electrode 13) Faraday effect detector mounted at Instead of this, ions Ion detectors that do not require direct impact on the detector to be detected (this latter Examples of types of detectors include resonant power absorption detectors and image current detectors. Other types of in-trap ion detection devices can be used, such as . The output of each in-trap ion detector is processed through the appropriate detector electronics. It is supplied to the sensor 29.

The control circuit 31 controls the basic voltage generator 14 and the filament lens control circuit 2. 1, and a control signal for controlling the supplementary AC voltage generator 35 is generated. circuit 31, in response to instructions received from processor 29, circuits 14.21, and 35, and in response to a request from processor 29, a control signal is sent to Data is sent to the processor 29.

A first embodiment of the preferred method of the invention will now be described with reference to FIG. . As shown in Figure 2, the first step of the method (proceeding during period A) is to This is to store parent ions in the parent ions. This traps the fundamental voltage signal ( quadrupole capture) by activating the basic voltage generator 14 of the apparatus of FIG. establishing the field and introducing the ionizing electron beam into the ion storage area 16; achieved by. Alternatively, the parent ions can be generated externally and transferred to the storage area. It is also possible to inject into area 16.

The fundamental voltage signal is transmitted by the trapping field (within the storage area 16) to the parent ion (e.g. (e.g., parent ions resulting from interactions between sample molecules and the ionizing electron beam) is a daughter ion (generated during period B) with a mass-to-charge ratio in the desired range. selected to be stored with.

generated in the trap during period A with a mass-to-charge ratio outside the desired range. Other ions that escape from zone 16 and, during period A, generate the "ion signal" shown in FIG. as these ions escape, as dictated by the value of 4 is saturated.

Before the end of period A, the ionizing electron beam is shut off at the gate.

Then, during period B, the first supplementary AC voltage signal (supplementary AC voltage generation of the apparatus of FIG. (such as by activating device 35). This voltage signal has a frequency selected to resonantly excite the selected daughter ions; The vibrationally excited daughter ions are transferred to a detector inside the trap (or a detector mounted outside the trap). an amplitude large enough to resonate to a degree that it can be detected by (i.e., electric power).

While a first supplementary AC voltage is applied to the trap by generator 35, generator 3 5 (or a second supplementary AC voltage generator connected to the appropriate electrodes). A supplemental alternating current voltage is applied to the trap. The power of the second supplementary AC voltage signal (applied output voltage) is less than the power of the first supplementary AC voltage signal (typically the second The power of the supplementary AC voltage signal is on the order of 100 mV, but the power of the first supplementary AC voltage signal is The power is on the scale of 1v). The second supplementary AC voltage signal is (to generate daughter ions) ) with a frequency selected to induce dissociation of a particular parent ion, but with an amplitude ( i.e. electric power), this electric power excites and traps a significant number of ions. The amplitude must be small enough to prevent it from resonating to the extent that it can be detected. (In embodiments using an in-trap ion detection device, the second supplementary AC voltage The signal should have sufficient power to resonantly induce dissociation of the selected parent ion. However, a significant number of ion trajectories excited by this power are trapped. It must have a low power such that it is not large enough to be detected. (No)

Then (also during period B) the frequency of the second supplementary AC voltage signal is modified to induce dissociation of ions. a common signal matching the frequency of the first complementary signal; Each daughter ion produced during this frequency scan, which happens to have an oscillating frequency, is made to resonate from a trap for emission (or composed of a trap electrode) or by an in-trap detection device installed with the trap electrode. ).

Thus, for example, the "ion signal" shown in period B of FIG. detected (with a common resonant frequency) resulting from sequential dissociation of parent ions of the form ) has four peaks, each representing a daughter ion.

An alternative method of inducing dissociation of several different parent ions is to use a second supplementary AC voltage signal. The signal frequency is kept fixed and the parameters of the acquisition field (i.e., the base height The frequency or amplitude of the alternating current component of the frequency voltage, or the amplitude of the direct current component of the fundamental high frequency voltage. one or more of the widths). Change the capture field like this By changing the frequency of each parent ion (each parent ion is within the trapping field) moving frequency) is changed respectively, and the frequency of another parent ion is changed to the second supplementary AC voltage signal. It occurs that the frequency of the signal is matched. If you change the capture field like this, The frequency of each daughter ion also changes, thus the frequency of the first supplementary AC voltage signal (At any point in time, the target daughter ion resonates with the first supplementary AC voltage signal. each must be changed so that the

During the period immediately following period B, all voltage signal sources are closed. Here, (i.e. , during period C of FIG. 2) the method of the invention can be repeated.

In a variation of the method of FIG. 2, the first or second supplementary alternating voltage signal (or ) has two or more different frequency components within the selected frequency range. have Each such frequency component includes a frequency and and amplitude characteristics.

A second preferred embodiment will now be described with reference to FIG. It is shown in Figure 3. The first step in this example (occurring during period A) is to trap the parent ion. It is to store it inside. This (starting the generator 14 of the device of FIG. 1) Therefore, apply a fundamental voltage signal to the trap to establish the quadrupole capture field and This is achieved by introducing an ionizing electron beam into the ion storage area 16. child An alternative method is to establish a quadrupole capture field and use an externally generated Parent ions are implanted into storage area 16.

The fundamental voltage signal is generated in the trap after period A by the acquisition field. The daughter ions, together with the parent ions, all have mass-to-charge ratios within the desired range. (in area 16) is chosen to be stored. (During period A, the phase with the electron beam Other ions (including those resulting from interactions) have mass-to-charge ratios outside the desired range. (When escaping, the detector 24 receives the "ion signal" in FIG. 3 during period A.) saturate as indicated by the value of )).

Before the end of period A, the ionizing electron beam is gated.

Then, during period B, the first supplementary AC voltage signal is applied to the trap (startup of the device in Figure 1). (such as by activating generator 35). This voltage signal is has a frequency (fpt) selected to induce dissociation of the parent ion (Pl) of However, a significant number of ions are excited within the trap and from outside the strap detection. The amplitude (i.e., the power ).

Then (also during period B) the first supplementary AC voltage signal is stopped and the "daughter" supplement An AC voltage signal is applied to the trap and the daughter of the first parent ion from the trap is detected. (or the daughter of the first parent ion is caused to resonate by the in-trap detector). (resonant enough to be detected). Thus, for example, period B in FIG. The “ion signal” portion shown within indicates that the first parent ion with a peak representing the detected daughter ion resulting from the dissociation of .

Rather than a single daughter complementary AC voltage signal (as shown during period B in Figure 3), two A set of one or more daughter complementary AC voltage signals may also be applied during period B. . Each signal in this set detects another daughter of the first parent ion (detector in the trap, or a frequency selected to resonate for detection (by an off-wrap detector); Should.

The same set of daughter supplemental AC voltage signals is traversed during periods CSD and E (discussed below). It can also be applied to the top.

Generally, the frequency of each daughter ion is different from the frequency of the parent ion. therefore, In one type of embodiment, the frequency of each daughter complementary AC voltage signal is equal to the frequency of the daughter complementary AC voltage signal. A small power supplement is applied to dissociate the parent daughter ions that are made to resonate by the voltage signal. foot variable current voltage signal (i.e. the "first" supplementary alternating current voltage signal referred to above, or “Second” and “Third” discussed with reference to periods “C”, “D”, and rEJ in FIG. , and the "fourth" supplementary AC voltage signal).

However, following the application of a low-power supplemental AC voltage signal, the application of a daughter supplementary AC voltage signal Before determining the parameters of the acquisition field (i.e., the frequency of the alternating component of the fundamental high-frequency voltage) one or more of the wave number or amplitude, or the amplitude of the DC component of the fundamental high frequency voltage) It is also within the scope of this invention to vary. Change the capture field like this By changing the frequency of each daughter ion (each daughter ion is within the trapping field) The moving frequency) is changed respectively, and the frequency of each daughter ion is changed to a small power supplemental AC voltage signal. can be truly matched to the signal frequency. In this latter case, the daughter complementary AC voltage signal Both the signal and the low-power supplementary AC voltage signal have the same frequency (these two supplementary The foot AC voltage signal can be fed to a "separate" acquisition field).

It is within the scope of the invention to perform only the steps described with reference to periods A and B of FIG. It is within. Alternatively, additional You can do the steps.

During period C (shown in Figure 3), a second supplementary AC voltage signal (of the apparatus of Figure 1) (such as by activating generator 35) to the trap. This voltage signal is another frequency (f) selected to induce dissociation of the second parent ion (P2). , 2), but this voltage signal excites and traps a significant number of ions. Small enough to not cause resonance to an extent sufficient to be detected by inside strap outside strap detection. It has an amplitude.

Then (also during period C), the second supplementary AC voltage signal is stopped and the daughter supplementary AC The voltage signal (or set of daughter complementary AC voltage signals) is again applied to the trap to generate a second parent ions are made to resonate for detection by the in-trap and out-strap detectors. . Figure 3 shows that no such daughter ion of interest is generated in response to the second complementary signal. This reflects the possibility that Thus, the ion signal shown within period C of FIG. The portion includes a detector generated by dissociation of the second parent ion during application of the second complementary signal. There are no peaks representing emitted daughter ions.

During the period, a third supplementary AC voltage signal (activating generator 35 of the apparatus of FIG. ) applied to the trap. This voltage signal is applied to the third parent ion. with another frequency (fp3) selected to induce dissociation of (P3), but significantly a sufficient number of ions are excited and detected outside the strap within the trap. has a small amplitude (ie, power) that cannot be caused to resonate.

Then (also for a period of time) the third supplementary AC voltage signal is stopped and the daughter supplementary AC voltage signal is stopped. The voltage signal (or set of daughter supplemental AC voltage signals) is again applied to the trap and the third parent ions are made to resonate for detection by the in-trap and out-strap detectors. . The “ion signal” portion shown within the period of FIG. has a peak representing the detected daughter ion resulting from dissociation of the third parent ion.

Then, during period E, a fourth daughter complementary alternating current voltage signal (powering generator 35 of the apparatus of FIG. applied to the trap (such as by activating it). This voltage signal is with another frequency (f, 4) selected to induce dissociation of the parent ion (P4). However, a significant number of ions are excited and resonated enough to be detected. The amplitude is as small as possible.

Then (also during period E), the fourth supplementary AC voltage signal is stopped and the daughter supplementary AC The voltage signal (or set of daughter complementary AC voltage signals) is again applied to the trap to Daughter ions of the fourth parent ion from the trap resonate (or enter the trap) for detection. (resonance) to a degree sufficient for detection by a detector. In Figure 3, such daughter Io It is reflected that no signal is generated in response to the fourth supplementary signal.

Thus, the portion of the ion signal shown within period E of FIG. There is no peak representing this.

During the period immediately following period E, all supplemental AC voltage signals are stopped. Here, the book The method of the invention is repeated (ie, during period F in FIG. 3).

In a variation of the method of FIG. 3, all or some of the supplementary AC voltages are having two or more different frequency components within a frequency range. Such frequency composition Each of the components must have the frequency and amplitude characteristics described above with reference to Figure 3. No.

A third preferred embodiment of the method of the invention will now be described with reference to FIG.

As shown in FIG. 4, the first step in this example (occurring during period A) is the parent ion is stored in a trap. This converts the fundamental voltage signal (of the device in Figure 1 by activating generator 14) to apply a quadrupole capture field to the trap. This is accomplished by determining the Ru. Alternatively, a quadrupole trapping field can be established and the externally generated parent ion is introduced into the storage area 16.

The fundamental voltage signals are all within the desired mass-to-charge range, depending on the acquisition field. (produced in the trap on interaction with the electron beam during period A) ) Daughter ions are chosen to be stored together with the parent ions (in the storage area 16).

Desired range (including ions produced by interaction with the electron beam during period A) Other ions with mass-to-charge ratios outside the detector 24 during period A (on escaping) (with saturation as shown by the value of "Ion Signal" in Figure 3) between zone 16 or escape from

Before the end of period A, the ionizing electron beam is shut off at the gate.

Thereafter, during period B, a first supplementary AC voltage signal (starting generator 35 of the apparatus of FIG. applied to the trap (such as by activating the ). This voltage signal is a frequency selected to resonantly excite the first parent ion (having a molecular weight PL-N); (f) and the first ion is L-N resonate to such an extent that it can be detected (by an external detector or a detector in the trap). have sufficient power (i.e., sufficient amplitude) to

The method of Figure 4 is particularly useful for analyzing "neutral loss" daughter ions. During ~ The sex-losing daughter ion has two components of the parent ion: a zero (neutral) charge and a molecule having a quantity N (N is sometimes referred to herein as "neutral loss mass") daughter molecule (e.g. water molecule) and P-N with a charge of 0 and P as the parent ion molecular weight. results from dissociation into a neutral loss mass having a molecular weight of . Thus, the method of Figure 4 During period B of , the first complementary signal causes the second complementary signal (with frequency fPI) the same mass-to-charge ratio that the neutral loss daughter ions produced later during the application of the The ions having the ion are caused to resonate.

Then (also during period B), the first supplementary AC voltage signal is stopped and the second supplementary AC voltage signal is A voltage signal is applied to the trap. The second supplementary AC voltage signal has a molecular weight P1 and a frequency selected to induce dissociation of the first parent ion. Second supplementary AC power The power of the voltage signal is less than the power of the first supplementary AC voltage signal (typically the power of the second The power of the supplementary AC voltage signal is about 100 mV, but the power of the first supplementary AC voltage signal is about 100 mV. The force is about IV). The power of the second supplementary AC voltage signal is significantly small enough that a large number of ions cannot be excited and resonated to the extent that they can be detected. Sai.

Next (also during period B), a third supplemental AC voltage signal is applied to the trap.

The third supplementary AC voltage signal has a frequency (fPi-N) and a second supplementary AC voltage signal (during period B). a neutral loss daughter with molecular weight PL-N (generated early during the application of a current voltage signal) to cause the ions to resonate to a sufficient degree for in-trap or out-of-trap detection. has sufficient amplitude.

The ion signal portion existing during period B of FIG. It has two peaks that occur during the addition. The second peak connects the first peak to the first parent. be interpreted with confidence as representing a neutral loss daughter ion resulting from the dissociation of an ion. Neutral loss daughter ions generated during application of the second complementary signal, whereas can be interpreted without any ambiguity as representing

Then, during period C, fourth, fifth, and sixth supplementary AC voltage signals are applied to the trap. are applied sequentially, thereby causing the dissociation of the second parent ion (having a molecular weight of P2) to It allows the detection of the resulting neutral loss daughter ion (having a molecular weight of P2-N).

The fourth and sixth supplementary voltage signals resonate the second ion (having a molecular weight of P2-N) with a frequency (f) selected to excite the second ion at cause it to resonate to the extent that it can be detected (by an external detector, a small instrument, or a detector inside the trap). It has enough power to

After application of the fourth supplementary voltage signal, this signal is stopped and the fifth supplementary AC voltage signal is turned on. applied to the lap. The fifth supplementary AC voltage signal is a second parent ionic voltage signal having a molecular weight of P2. has a frequency selected to induce on-dissociation. Fifth supplementary AC voltage signal voltage The force is less than the power of the fourth and sixth supplementary voltage signals (typically 100 m V), a significant number of ions are excited and detected by the fifth supplementary voltage signal. It is small enough that it cannot resonate to any extent.

Then (also during period C) a sixth supplementary AC voltage signal is applied to the trap. . The sixth supplementary AC voltage signal has the frequency (fP2-N) and the fourth supplementary AC voltage signal of (period C). A neutral loss daughter with a molecular weight of P2-N (generated early during the application of a voltage signal) It has sufficient amplitude to cause ions to resonate to the extent that they can be detected.

Figure 4 shows the possibility that no such neutral daughter ion is generated in response to the fifth complementary signal. gender is reflected. Thus, during the application of the sixth supplementary signal (within period C of FIG. 4) The resulting ion signal portion includes the ion signal detected during the application of the fourth supplementary signal. Although there are peaks representing the sample ions that are There are no peaks representing detected neutral loss daughter ions produced by the dissociation of ions.

Finally, during the period, the seventh, eighth, and ninth supplementary AC voltage signals are applied to the trap. are sequentially applied to ( allows the detection of neutral loss daughter ions (with a molecular weight of P3-N). 7th and 7th 9 The complementary voltage signal resonantly excites the third ion (having a molecular weight of P3-H) frequency (f, 3□) selected to detect the third ion (external detector or each has enough power to cause it to resonate to the extent that it is detected (by an in-chip detector). do.

After application of the seventh supplementary voltage signal, this signal is stopped and the eighth supplementary AC voltage signal is turned on. applied to the lap. The eighth supplementary AC voltage signal is a third parent ionic acid having a molecular weight of P3. has a frequency selected to induce on-dissociation. 8th supplementary AC voltage signal voltage The force is less than the power of the seventh and ninth supplementary voltage signals (typically 100 mV degree), to the extent that a significant number of ions are excited and detected by the eighth supplementary voltage signal. It is small enough that it cannot be caused to resonate.

Next (and also for a period of time), a ninth supplementary AC voltage signal is applied to the trap.

The ninth supplementary AC voltage signal has a frequency (fP3-N) and a molecular weight of P3-N. Neutral loss daughter ions (generated during application of the seventh supplementary voltage signal) are detected It has an amplitude sufficient to resonate up to a degree.

The ion signal portion that occurs during the application of the ninth supplementary signal (period D in Figure 4) is The eighth supplementary signal has no peaks representing ions detected during the application of the signal. Detected neutral loss daughter ions produced by dissociation of the third parent ion during application It has a peak representing .

In one variation of the method of Figure 4, only the operations described with reference to periods A and B is performed to detect neutral loss daughter ions for only one parent ion.

In another variation of the method of FIG. An additional series of operations (including steps corresponding to Neutral loss daughter ions for not only three but more parent ions (such as is detected.

In general, the frequency of each neutral loss daughter ion is the frequency of the parent ion of each neutral loss daughter ion. Different from wave number. Therefore, in one type of embodiment, the period rB of FIG. The frequency of each high power supplemental AC voltage signal applied between one of J, “C”, or rDJ. The wave number is the frequency of the low power supplementary AC voltage signal applied during the same period of the period in Figure 4. is different.

However, following the application of each low-power supplemental AC voltage signal, the next high-power supplemental AC voltage signal Before signal application, the acquisition field parameters (i.e., the fundamental high-frequency voltage one of the frequency or amplitude of the current component, or the amplitude of the direct current component of the fundamental high frequency voltage; It is also within the scope of the embodiment of FIG. captured like this By changing the trapping field, the frequency of each neutral loss daughter ion (each neutral loss The frequency at which the lost daughter ion moves in the trapping field is changed, and each neutral loss The frequency of the aborted daughter ions is truly matched to the frequency of the low power supplemental alternating current voltage signal. After this In the case of These two complementary AC voltage signals are applied to the “separate” acquisition field at the same frequency. It can have a wave number.

In another class of embodiments of the invention, granddaughter ions (in addition to daughter ions) are generated in zone 16 and subsequently detected (rather than daughter ions). for example, During stage B of the method of FIG. It consists of a period part. That is, the early part (by dissociating the parent ion) The latter part has a frequency selected to induce the generation of daughter ions ( with a frequency selected to induce the generation of granddaughter ions (by dissociating). Ru. In this example, the first (higher power) supplemental AC voltage signal applied during period B is , is selected to match the resonant frequency of the granddaughter ion (rather than the daughter ion).

For another example, during step B of the method of FIG. The voltage signal consists of an early part followed by a late part. That is, the early part is (first a frequency selected to induce the production of daughter ions (by dissociating the parent ion) the late part is responsible for the generation of granddaughter ions (by dissociating the daughter ions). has a frequency selected to guide it. In this example, applied during period B The second (higher power) supplemental AC voltage signal is at the resonant frequency of the granddaughter ion (rather than the daughter ion). selected to match the wavenumber.

In the claims, the phrase "daughter Aeon" refers to the first generation daughter Aeon as well as grandchild Aeon. Daughter Aeon (the next generation of Daughter Aeon) and subsequent (third generation or successor) generation Daughter Ion Intended to call on.

In a variant of the embodiment of the invention described with reference to FIG. One of the foot AC voltage signals (or a set of "daughter" supplementary AC voltage signals) is connected to the first, second , third, or once immediately before one of the fourth (low power) supplementary AC voltage signals, and the first, Immediately after the same one signal of the second, third, or fourth (low power) supplementary AC voltage signal again is applied twice. The purpose of each such "preliminary" application is to ensure that the daughter ions have Ions with the same mass-to-charge ratio as the (as in the embodiment of the invention described with reference to FIG. 4). It is about generating.

Various other modifications and variations of the methods described for this invention may be made within the scope and spirit of this invention. It will be clear to those skilled in the art that this can be done without departing from the spirit. Specify the present invention Although described with respect to preferred embodiments, the claimed invention extends to such specific embodiments. It should be understood that this is not an unreasonable limitation.

S-A’ B 5-C--← FIG.3 Copy and translation of written amendment) Submission (Article 184-8 of the Patent Law) August 27, 1993 1 International application number PCT/US 92101104 2 Name of the invention Mass spectrometry using supplemental alternating voltage signals 3 Patent applicant Address: United States, California 94039-7244, Mt. N View, Terra Bella Avenue 1274 Name: Teledyne ME G 4 agents Address: 8th floor, Sogo Nagatacho Building, 1-11-28 Nagatacho, Chiyoda-ku, Tokyo The scope of the claims (a) A trapping field capable of trapping parent ions and daughter ions is created using one set of electrodes. determined within a demarcated capture area; (b) having a first frequency that matches the resonant frequency of the first trapped parent ion; A low power supplemental alternating current voltage signal is applied to the electrode to induce dissociation of the first trapped parent ion. height, (c) a high power supplement having a second frequency matching the resonant frequency of the first daughter ion; Applying an alternating voltage signal to the electrode to generate a first resonant frequency within the capture field. the first daughter ion to a sufficient extent to enable detection of the first daughter ion having a number of (d) having a third frequency matching the resonant frequency of the second trapped parent ion; applying a second low power supplemental AC voltage signal to the electrode to cause dissociation of the second parent ion; (e) detecting the second daughter ion; causing the second daughter ion to resonate to a sufficient extent to enable emission, (f) before or during step (C), the acquisition field is a second trap in which the first daughter ions have a second resonant frequency substantially equal to the second frequency; change to capture field Mass spectrometry method, including steps.

2. The mass spectrometry method of claim 1, wherein the first frequency is different from the second frequency.

3. said step (f) is performed after said step (b), and said first frequency is substantially before said step (b); 2. The mass spectrometry method of claim 1, wherein the second frequency is equal to the second frequency.

4. The high power supplemental AC voltage signal causes the first daughter ions to leave the trapping area. 2. The mass spectrometry method of claim 1, wherein the mass spectrometry method is resonantly emitted, and detecting the emitted first daughter ions with a detector located outside the capture zone; A method, including steps.

5. The first daughter ion is detected in the trap by the high power supplemental AC voltage signal. 2. The mass of claim 1, wherein the mass is made to resonate to an extent sufficient for detection within the trap by a device. Analysis method.

6. (a) A trapping field capable of trapping parent ions and daughter ions is created using one set of electrodes. determined within a demarcated capture area; (b) having a first frequency that matches the resonant frequency of the first trapped parent ion; A low power supplemental alternating current voltage signal is applied to the electrode to induce dissociation of the first trapped parent ion. height, (C) having a second frequency matching the resonant frequency of the first daughter ion; at least one of said electrodes, or at least one of said electrodes. Detection inside the trap is possible with the inside-trap detector installed integrally with the one A high power supplemental AC voltage signal is applied to the electrode to cause it to resonate to the extent that the first daughter causing the first daughter ion to resonate to a sufficient extent to enable detection of the ion; (d) at least one of the electrodes, while leaving the first daughter ion within the capture zone; A method comprising detecting at one location.

7. The acquisition field of claim 6, wherein the acquisition field is a three-dimensional quadrupole acquisition field. A mass spectrometry method, wherein step (a) comprises: Applying a fundamental voltage signal having a high frequency component to the electrode Mass spectrometry method, including steps.

8. (a) A trapping field capable of trapping parent ions and daughter ions is created using one set of electrodes. determined within a demarcated capture area; (b) having a first frequency that matches the resonant frequency of the first trapped parent ion; A low power supplemental alternating current voltage signal is applied to the electrode to induce dissociation of the first trapped parent ion. height, (c) a high power supplement having a second frequency matching the resonant frequency of the first daughter ion; applying an alternating voltage signal to the electrode to an extent sufficient to enable detection of the first daughter ion; causing the first daughter ion to resonate until the step (b) and (c) are performed simultaneously. Mass spectrometry method, including steps.

9. 2. The mass spectrometry method according to claim 1, wherein step (e) comprises: a second high power supplement having a fourth frequency matching the resonant frequency of the second daughter ion; applying an alternating current voltage signal to said electrode to enable detection of said second daughter ion; causing the second daughter ion to resonate to such an extent.

10. The mass of claim 9, wherein the second frequency is substantially equal to the fourth frequency. Analysis method.

11. The mass spectrometry method according to claim 1, wherein the step (c) is performed after the step (b). and, before step (b), a frequency substantially equal to the second frequency. applying a second high power supplemental alternating current voltage signal having a resonantly eject ions with a mass-to-charge ratio that matches the mass-to-charge ratio of the A method, including steps.

12. The mass spectrometry method according to claim 1, further comprising, before said step (b), said a third high power supplemental alternating current voltage signal having a frequency substantially equal to the second frequency; the first daughter ion having a mass-to-charge ratio that matches the mass-to-charge ratio of the first daughter ion; resonantly emit ions having a frequency substantially equal to the third frequency. A fourth high power supplemental AC voltage signal is applied to the electrode to determine the mass ratio of the second daughter ion. and resonantly ejecting ions having a mass-to-charge ratio matching the charge ratio. Hmm, method.

13. (a) A set of quadrupole trapping fields capable of trapping parent ions and daughter ions defined within a trapping zone delimited by the electrode, and trapping parent ions within the trapping zone; death, (b) a first frequency that then matches the resonant frequency of a first ion of the parent ion; applying a low power supplemental alternating current voltage signal having a inducing dissociation of on to generate a first daughter ion, (c) while performing step (b), a second daughter ion matching the resonant frequency of the first daughter ion; Detecting the first daughter ion by applying a high power supplemental AC voltage signal having a frequency to the electrode. The first daughter ions are resonated to a sufficient extent to enable the low power supplemental AC current to be generated. The voltage signal has a power of about 100 mV, and the high power supplementary AC voltage signal has a power of about 1 V. have power Mass spectrometry method, including steps.

14. (a) One set of quadrupole trapping fields that can trap parent ions and daughter ions within a trapping zone delimited by electrodes, and trapping parent ions within the trapping zone. capture, (b) then having a first frequency matching the resonant frequency of the first species of the parent ion; applying a low power supplemental alternating current voltage signal to the electrode to cause the first type of solution of the first parent ion to inducing separation to generate a first daughter ion; (c) while performing step (b); a high power supplemental AC current having a second frequency matching the resonant frequency of the first daughter ion; applying a pressure signal to the electrode to a sufficient extent to enable detection of the first daughter ion. Make the first daughter ion resonate, (d) after step (b), changing the frequency of the low power supplemental AC voltage signal to induce the dissociation of another ion, (e) continuing to apply said high power supplemental alternating current voltage signal to said electrode while performing step (d); to a sufficient extent to enable detection of the daughter ions generated during step (d). Make daughter ions resonate Mass spectrometry method, including steps.

15. (a) One set of quadrupole trapping fields that can trap parent ions and daughter ions within a trapping zone delimited by electrodes, and trapping parent ions within the trapping zone. capture, (b) a first frequency that then matches the resonant frequency of the first ion of the parent ion; applying a low power supplemental alternating current voltage signal having a inducing dissociation of on to generate a first daughter ion, (c) while performing step (b), a target having a first resonant frequency within the capture zone; a high power supplemental alternating current voltage having a second frequency matched to the resonant frequency of the first daughter ion; A signal is applied to the electrode to detect the first daughter ion to a sufficient extent to enable detection of the first daughter ion. Make the first daughter ion resonate, a second ion of the parent ion having the first resonant frequency; 2 acquisition fields to continuously apply the low power supplemental AC voltage signal to the electrodes. inducing the dissociation of the second ion from the parent ion by applying a A second daughter ion having a second resonant frequency is generated in the waveguide to supplement the high power. The frequency of the alternating voltage signal is adjusted to a level sufficient to enable detection of the second daughter ion. Change the second daughter ion to resonate to match the second resonance frequency. Mass spectrometry method, including steps.

16. (a) A set of quadrupole trapping fields capable of trapping parent ions and daughter ions locating a first parent ion within a trapping zone delimited by an electrode; Captured with (b) after step (a), a first frequency matching the resonant frequency of the first parent ion; applying a low power supplemental AC voltage signal to the electrode to induce dissociation of the first parent ion; to generate the first daughter ion, (c) after performing step (b), a second frequency matching the resonant frequency of the daughter ion; applying a high power supplemental alternating current voltage signal with a voltage to the electrode to enable detection of the daughter ions; The daughter ions are caused to resonate to a sufficient extent that the low power supplemental AC voltage signal is The high power supplementary AC voltage signal has a power of about 1 V. Method, including steps.

17. (a) One set of quadrupole trapping fields that can trap parent ions and daughter ions a first parent ion within a trapping zone delimited by electrodes of the trapping zone; captured inside, (b) After step (a), applying a high power supplemental alternating current voltage signal to the electrode to remove the first mass. a first ion having a charge-to-charge ratio to a sufficient extent to enable detection of the first ion. make it resonate with (c) after step (b), a first frequency matching the resonant frequency of the first parent ion; applying a low power supplemental AC voltage signal to the electrode to induce dissociation of the first parent ion; having a first resonant frequency within the capture zone and having the first mass-to-charge ratio. generate a first daughter ion, (d) after performing step (c), a second frequency matching the resonant frequency of the first daughter ion; A second high power supplemental AC voltage signal having a wave number is applied to the electrode to induce the first daughter ion. resonating the first daughter ion to a sufficient extent to enable detection of the first daughter ion; (e) after step (b) and before step (c), transmitting the acquisition field to the second frequency; a second trapping field in which the daughter ions have a second resonant frequency substantially equal to change to Mass spectrometry method, including steps.

18. The first parent ion has a molecular weight equal to Pl, and the first ion and the Claim that the daughter ion has a molecular weight equal to PL-N, where N is the neutral loss mass. The mass spectrometry method according to item 17.

19. The mass spectrometry method according to claim 17, wherein the first frequency is different from the second frequency. .

20. also trapping a second parent ion within the trapping zone during step (a); 18. The mass spectrometry method according to claim 17, further comprising: (f) after said step (e), applying a third high power supplemental AC voltage signal to said electrode; and to an extent sufficient to enable detection of a second ion having a second mass-to-charge ratio. causing the second ion to resonate until (g) after step (f), a third frequency matching the resonant frequency of said second parent ion; a second low power supplemental alternating current voltage signal having a number of inducing dissociation to produce a second daughter ion having the second mass-to-charge ratio; (h) after carrying out step (g), a fourth ion matched to the resonant frequency of the second daughter ion; applying a fourth high power supplemental AC voltage signal having a frequency to the electrode to causing the second daughter ion to resonate to a sufficient extent to enable detection of the on state; A mass spectrometry method that also includes steps.

21, the first parent ion has a molecular weight P1, and the first ion and the first daughter ion ion has a molecular weight PL−N, where N is the neutral loss mass, and the second parent ion has a molecular weight P2, and the second ion and the second daughter ion have a molecular weight P2-N. The mass spectrometry method according to claim 20.

22. The low power supplementary AC voltage signal has a power of about 100 mV, and the high power 18. The mass spectrometry method of claim 17, wherein the supplemental alternating voltage signal has a power on the order of 1 volt.

23. The mass spectrometry method of claim 17, further comprising: (f) after said step (e). , a small power supplement with a frequency matching the resonant frequency of the captured parent ion. applying an alternating voltage signal to the electrode to induce dissociation of the trapped parent ion; (g) After step (f), a large electric current having a frequency matching the resonant frequency of the daughter ions is applied. a force sufficient to apply a complementary alternating current voltage signal to the electrode to enable detection of the daughter ion. Make the daughter ion resonate to the extent A method, including steps.

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Claims (32)

[Claims] 1. (a) A trapping field capable of trapping parent ions and daughter ions is created using one set of electrodes. determined within a demarcated capture area; (b) having a first frequency that matches the resonant frequency of the first trapped parent ion; applying a low power supplemental alternating voltage signal to the electrode to induce dissociation of the first trapped parent ion; let me, (c) a high power supplement having a second frequency matching the resonant frequency of the first daughter ion; applying an alternating voltage signal to the electrode sufficient to enable detection of the first daughter ion; make the first daughter ion resonate until Mass spectrometry method, including steps. 2. 2. The mass spectrometry method of claim 1, wherein the first frequency is different from the second frequency. 3. the first daughter ion has a first resonant frequency within the trapping field; The mass spectrometry method according to claim 1, further comprising: (d) during or after step (c), the trapping field is adjusted to the first daughter ion; a second acquisition filter having a second resonant frequency substantially equal to the second frequency; change to field A method, including steps. 4. said step (d) is performed after said step (b), said first frequency being substantially before said step (b); 4. The mass spectrometry method of claim 3, wherein the second frequency is equal to the second frequency. 5. The high power supplemental AC voltage signal causes the first daughter ions to be removed from the trapping area. 2. The mass spectrometry method of claim 1, wherein the mass spectrometry method is resonantly emitted, and detecting the emitted first daughter ions with a detector located outside the capture zone; A method, including steps. 6. The first daughter ion is detected in the trap by the high power supplemental AC voltage signal. 2. The mass of claim 1, wherein the mass is made to resonate to an extent sufficient for detection within the trap by a device. Analysis method. 7. the in-trap detector is comprised of at least one of the electrodes, or or integrally attached with at least one of said electrodes. A quantitative analytical method, which also includes: at least one of the electrodes, leaving the first daughter ions within the capture zone. The method also includes the step of detecting at one location. 8. 2. The acquisition field of claim 1, wherein the acquisition field is a three-dimensional quadrupole acquisition field. A mass spectrometry method, wherein step (a) comprises: Applying a fundamental voltage signal having a high frequency component to the electrode Method, including steps. 9. The mass spectrometry method according to claim 1, wherein steps (b) and (c) are performed simultaneously. 10. The mass spectrometry method according to claim 1, wherein said step (c) is performed after said step (b). And also, (d) having a third frequency that matches the resonant frequency of the second trapped parent ion; applying a second low power supplemental alternating current voltage signal to the electrode to resolve the second trapped parent ion; induce separation, (e) after step (d), a fourth frequency matching the resonant frequency of the second daughter ion; applying a second high power supplemental alternating current voltage signal having a second daughter ion to the electrode; causing the second daughter ion to resonate to a sufficient extent to enable detection. A method, including steps. 11. The mass of claim 1, wherein the second frequency is substantially equal to the fourth frequency. Analysis method. 12. The mass spectrometry method according to claim 1, wherein said step (c) is performed after said step (b). And also, (d) before step (b), a second frequency having a frequency substantially equal to said second frequency; 2 high power supplemental AC voltage signals are applied to the electrodes to determine the mass vs. Resonantly eject ions with mass-to-charge ratios that match the charge ratios A method, including steps. 13. said first captured parent ion has a molecular weight equal to P; said first daughter ion has a molecular weight equal to P; 12. 12. On has a molecular weight equal to PN, where N is the neutral loss mass. Mass spectrometry method as described. 14. The mass spectrometry method according to claim 1, wherein said step (c) is performed after said step (b). And also, (d) after said step (c), a third frequency matched to the resonant frequency of said second daughter ion; applying a second high power supplemental alternating current voltage signal having a number to said electrode to cause said second daughter ion to cause the second daughter ion to resonate to a sufficient extent to enable detection of the second daughter ion. A method, including steps. 15. 15. The mass spectrometry method of claim 14, further comprising: (e) before step (b). a third high power supplemental alternating current voltage having a frequency substantially equal to said second frequency; applying a signal to the electrode to match the mass-to-charge ratio of the first daughter ion; a frequency substantially equal to the third frequency; applying a fourth high power supplemental AC voltage signal having a number to the electrode to induce the second daughter ion. resonantly eject ions with a mass-to-charge ratio that matches the mass-to-charge ratio of A method, including steps. 16. (a) A set of quadrupole trapping fields that can trap parent and daughter ions. defined within a trapping zone delimited by the electrode, and trapping parent ions within the trapping zone; death, (b) a first frequency that then matches the resonant frequency of a first ion of the parent ion; applying a low power supplemental alternating voltage signal to the electrode having a low power supplemental alternating voltage signal having to induce dissociation of and generate a first daughter ion, (c) while performing step (b), a second daughter ion matching the resonant frequency of the first daughter ion; Detecting the first daughter ion by applying a high power supplemental AC voltage signal having a frequency to the electrode. cause the first daughter ion to resonate to a sufficient extent to enable emission. Mass spectrometry method, including steps. 17. The low power supplementary AC voltage signal has a power of about 100 mV, and the high power 17. The mass spectrometry method of claim 16, wherein the supplemental alternating voltage signal has a power on the order of 1V. 18. The step (c) is performed by changing the frequency of the low power supplemental AC voltage signal. 17. The method of claim 16, further comprising the step of inducing dissociation of another ion of the parent ion. Mass spectrometry. 19. the first parent ion has a first resonant frequency within the trapping field; 17. The mass spectrometry method according to claim 16, wherein step (c) comprises: a second ion of the parent ion having the first resonant frequency; changing to a second acquisition field to transmit the low power supplemental alternating voltage signal to the electrodes; The dissociation of the second ion of the parent ion is induced by continuous application, resulting in the second capture. generating second daughter ions having a second resonant frequency in the field; changing the frequency of the power supplemental alternating current voltage signal to enable detection of the second daughter ion; matched to the second resonant frequency to cause the second daughter ions to resonate to a sufficient extent that let Method, including steps. 20. (a) A set of quadrupole trapping fields that can trap parent and daughter ions. locating a first parent ion within a trapping zone delimited by an electrode; Captured with (b) after step (a), a first frequency matching the resonant frequency of the first parent ion; inducing dissociation of the first parent ion by applying a low power supplemental alternating current voltage signal to the electrode having a to generate daughter ions, (c) after carrying out step (b), a second frequency matching the resonant frequency of the daughter ion; The daughter ions can be detected by applying a high power supplemental AC voltage signal having a number to the electrodes. A method of mass spectrometry comprising the step of causing the daughter ions to resonate to an extent sufficient to cause the daughter ions to resonate. 21. also trapping a second parent ion within the trapping zone during step (a); 21. The mass spectrometry method according to claim 20, further comprising: (d) after said step (c), a third frequency matching the resonant frequency of said second parent ion; A second low power supplemental AC voltage signal having a wave number is applied to the electrode to cause the second parent ion to (e) after performing step (d), inducing the dissociation of the ions to generate daughter ions; a second high power supplemental alternating current having a fourth frequency matched to the resonant frequency of the daughter ion; A voltage signal is applied to the electrode to detect the daughter ion to a sufficient extent to enable detection of the daughter ion. Make daughter ions resonate A method, including steps. 22. 22. The quality of claim 21, wherein the fourth frequency is substantially equal to the second frequency. Quantitative analysis method. 23. 21. The mass spectrometry method of claim 20, wherein the first frequency is different from the second frequency. . 24. The daughter ions have a first resonant frequency within the trapping field. 21. The mass spectrometry method according to claim 20, further comprising: (d) after said step (b) and before said step (c), said acquisition field is a second trapping in which the ions have a second resonant frequency substantially equal to said second frequency; change to field A method, including steps. 25. The low power supplementary AC voltage signal has a power of about 100 mV, and the high power 21. The mass spectrometry method of claim 20, wherein the supplemental alternating voltage signal has a power on the order of 1V. 26. (a) A set of quadrupole trapping fields that can trap parent and daughter ions. locating a first parent ion within a trapping zone delimited by an electrode; Captured with (b) after step (a), applying a high power supplemental alternating current voltage signal to the electric oak; the first ion to a sufficient extent to enable detection of a first ion having a mass-to-charge ratio. make the on resonate, (c) after step (b), a first frequency matching the resonant frequency of the first parent ion; inducing dissociation of the first parent ion by applying a low power supplemental alternating voltage signal to the electrode having a generating a first daughter ion having the first mass-to-charge ratio; (d) after step (c), a second frequency matching the resonant frequency of the first daughter ion; applying a second high power supplemental alternating current voltage signal having causing the first daughter ion to resonate to a sufficient extent to enable detection. Mass spectrometry method, including steps. 27. The first parent ion has a molecular weight P1, and the first ion and the first daughter ion 27. The on has a molecular weight P1-N, where N is the neutral mass lost. Mass spectrometry. 28. 27. The mass spectrometry method of claim 26, wherein the first frequency is different from the second frequency. . 29. The daughter ions have a first resonant frequency within the trapping field. 27. The mass spectrometry method according to claim 26, further comprising: (d) after said step (b) and before said step (c), said acquisition field is a second trapping in which the ions have a second resonant frequency substantially equal to said second frequency; change to field A method, including steps. 30. also trapping a second parent ion within the trapping zone during step (a); 27. The mass spectrometry method according to claim 26, further comprising: (e) after said step (d), applying a third high power supplemental AC voltage signal to said electrode; to a sufficient extent to enable detection of a second ion having a second mass-to-charge ratio. to cause the second ion to resonate, (f) after said step (e), a third frequency matching the resonant frequency of said second parent ion; a second low power supplemental alternating current voltage signal having a number of inducing dissociation to produce a second daughter ion having the second mass-to-charge ratio; (g) after carrying out step (f), a fourth ion which matches the resonant frequency of the second daughter ion; a fourth high power supplemental alternating current voltage signal having a frequency of causing the second daughter ion to resonate to a sufficient extent to enable detection of the ion; A method, including steps. 31. The first parent ion has a molecular weight P1, and the first ion and the first daughter ion ion has a molecular weight P1-N, where N is the neutral loss mass, and the second parent ion has a molecular weight P2, and the second ion and the second daughter ion have a molecular weight P2-N. 31. The mass spectrometry method according to claim 30. 32. The low power supplementary AC voltage signal has a power of about 100 mV, and the high power 27. The mass spectrometry method of claim 26, wherein the supplemental alternating voltage signal has a power on the order of 1V.