42 results about "Accelerator mass spectrometry" patented technology

A mass spectrometry system based on the general principle of accelerator mass spectrometry (AMS) is disclosed. An ion source (10) generates a beam (B) of ions having a negative charge state. A first mass analyzer (20) transmits only ions having a predetermined mass. The ions are passed through a stripper target (80) comprising helium and / or hydrogen as a stripping gas to change the charge state of said ions from negative to positive charge and to dissociate molecular ions by collisions. A second mass analyzer (110, 130) transmits ions in charge state 1+ having the predetermined mass, which are detected by a detector (140). By using helium and / or hydrogen gas and detecting ions in charge state 1+, it becomes possible to use kinetic energies below 200 keV without excessive transmission losses due to angular straggling. At sufficiently low energies, no additional acceleration is required after ions have been extracted from the ion source. In alternative embodiments, no mass selection is carried out before charge exchange takes place.

The invention provides a calibrating method for use in a method of determining the quantity of an analyte labelled with an AMS isotope in a test sample, said calibrating method comprising: (i) contacting a plurality of samples contaminated with neither said analyte nor a non-labelled counterpart analyte with a known quantity of said counterpart analyte and a quantity C of analyte to afford a plurality of calibrating samples, wherein each of said calibrating samples contains a known quantity of counterpart analyte but a different quantity of C; (ii) measuring by AMS the quantity C of analyte added to each of the plurality of samples; (iii) separating the analyte and counterpart analyte from other species in the plurality of samples to afford a plurality of purified samples; (iv) measuring a quantity A of analyte in said purified samples by AMS; and (v) measuring a quantity B of counterpart analyte in said purified samples.

The invention provides a calibrating method for use in a method of determining the quantity of an analyte labeled with an accelerator mass spectrometry (AMS) isotope in a test sample. The samples can include, for example, urine, faeces, plasma or blood. The analyte can be, for example, a drug or metabolite of a drug.

This invention relates to a method and apparatus for separation of rare stable or radioactive isotopes from their atomic or molecular isobars in mass spectrometry (MS). In the present invention, the approach taken to removing atomic isobars utilizes a high transmission device for decelerating ions in combination with low energy reactions, such as ion-molecule reactions or near resonant electron transfer, in RF ion guides. The isobar is selectively depleted by electron transfer or other reactions between negative ions and gaseous targets in pressurized RF ion guides at low energies. The energy is controlled in such a way as to prevent reaction of the ion of interest while inducing reactions with the undesired isobar interference. The technique is of particular relevance to accelerator mass spectrometry (AMS) for which it allows substantial reductions in the necessary terminal voltage. The effect is to allow reductions in the size and cost of AMS installations.

The invention discloses an isotopic tracing method for monitoring cancer cell osseous metastasis. The method refers to a measurement method by taking 41Ca as a tracer agent and taking accelerator mass spectrometry (AMS) as a tracer agent and is used for monitoring the occurrence, development and resolution processes of the cancer cell osseous metastasis, and belongs to the technical field of nuclear technologies. The method disclosed by the invention comprises the following steps: (1) generating a 41Ca marked tracer agent; (2) marking an experimental nude mouse by using the 41Ca marked tracer agent; (3) collecting a urine sample of the nude mouse in the step (2), and separating the element Ca; (4) measuring the 41Ca / 40Ca isotope abundance ratio in the calcium fluoride powder obtained in the step (3); and (5) drawing a standard curve; and (6) analyzing the difference, so as to obtain the cancer cell osseous metastasis degree. According to the method disclosed by the invention, the problems that the sensitivity of a conventional monitoring means is relatively low and the early monitoring of the cancer cell osseous metastasis is difficultly realized are solved, and the method has high clinical application values and social benefits.

A mass spectrometry system based on the general principle of accelerator mass spectrometry (AMS) is disclosed. An ion source (10) generates a beam (B) of ions having a negative charge state. A first mass analyzer (20) transmits only ions having a predetermined mass. The ions are passed through a stripper target (80) comprising helium and / or hydrogen as a stripping gas to change the charge state of said ions from negative to positive charge and to dissociate molecular ions by collisions. A second mass analyzer (110, 130) transmits ions in charge state 1+ having the predetermined mass, which are detected by a detector (140). By using helium and / or hydrogen gas and detecting ions in charge state 1+, it becomes possible to use kinetic energies below 200 keV without excessive transmission losses due to angular straggling. At sufficiently low energies, no additional acceleration is required after ions have been extracted from the ion source. In alternative embodiments, no mass selection is carried out before charge exchange takes place.

The present invention provides an accelerator mass spectrometry device for simultaneously measuring isotopes. In one embodiment, the device comprises a sputtering negative ion source for generating negative ions; the sputtering negative ion source being connected to an accelerating tube for simultaneously accelerating a plurality of isotopic ions; an output end of the accelerating tube being connected to an isotope mass resolution system; the isotope mass resolution system being connected to a charge conversion analysis and multi-receiving measurement system; the charge conversion analysis and multi-receiving measurement system being connected to an ion detection system. The present invention is capable of accelerating a plurality of isotopic negative ions simultaneously. The accelerated isotopic negative ions are separated. Stable isotopic negative ions are measured by a stable isotope receiver. Unstable isotope negative ions are converted to positive ions and then measured by a detector.

The present invention provides a method of sample preparation for use in obtaining elemental isotope ratios of a material by accelerator mass spectrometry. The method comprises forming the material into a sample without any substantial chemical alteration of the material. The invention also provides a sample for use in obtaining elemental isotope ratios of a material.

An accelerator mass spectrometry system for measuring an isotopic ratio of a chemical element in a sample. The system includes an ion source generating a beam of negative ions of the chemical element containing ions of first and second isotopes of the chemical element, a first analyzer section, comprising a first mass analyzer; a tandem accelerator comprising a first accelerating section, a charge stripping section for converting the negative ions into positive ions, and a second accelerating section behind the charge stripping section. A second analyzer section includes a second mass analyzer and an electrostatic analyzer; a particle detector; and a controller system configured to control the first mass analyzer section and the second analyzer section such that the ions of the first and second isotopes traverse the tandem accelerator and ions of only one of the first and second isotopes enter the particle detector. An additional analyzer is located in between the charge stripping section and the second accelerating section and is configured to receive positive ions that have exited the charge stripping section and to separate positive ions having a charge state corresponding to a predetermined charge-state value from positive ions having a charge state not corresponding to the predetermined charge-state value, so as to transmit ions with different charge states in mutually different directions such that only ions having a charge state corresponding to the predetermined charge-state value are transmitted towards the particle detector.

The invention discloses a method for carrying out accelerator mass spectrometry measurement by using super halogen anions of beryllium. The method is characterized by comprising the following steps: preparing a target sample capable of producing super halogen anions BeF3<->; bombarding the target sample and a PbF2 powder mixing target cone to generate a BeF3<-> beam; crushing the BeF3<-> beam in a tandem accelerator; enabling <9>Be<2+> to enter a mobile Faraday cup for measurement after passing through a main analysis magnet; enabling <10>Be<2+> to pass through along a main beam line and to directly pass through a main electrostatic analyzer and a second magnet at the high-energy end; and finally entering a gas detector for analysis. The method has the beneficial effects that interference of <10>B is effectively inhibited at the extraction stage by the extracted beam which is measured by taking BeF3<-> as <10>Be-AMS, so that the high-energy end of a miniature AMS does not need to be peeled off twice by using an energy-reducing film, and the transmission efficiency of the <10>Be beam is ensured (the high-energy end achieves 100% transmission), the original good beam quality is maintained in the absence of the film, and the risks to experimenters due to the fact that BeO as airborne dust has high toxicity are effectively avoided.

A polyacrylic acid (salt), or a polyacrylic acid (salt)-based water-absorbing resin, contains a tracer for detecting various troubles in the water-absorbing resin during the period from the production of the water-absorbing resin to the use and discard thereof by a consumer. The polyacrylic acid (salt)-based water-absorbing resin has a stable carbon isotope ratio, as determined by accelerator mass spectrometry, of less than −20‰ and a radioactive carbon content of 1.0×10−14 or more. The polyacrylic acid (salt)-based water-absorbing resin has: a CRC of 10 [g / g] or more; an AAP of 20 [g / g] or more; an Ext of 35 wt. % or less; a content of residual monomers of 1,000 ppm or less; a PSD in which the proportion of particles having a particle diameter of 150 μm or larger but less than 850 μm is 90 wt. % or more; and an FSR of 0.15 [g / g / s] or more.

The invention discloses a method for measuring accelerator mass spectrometry using super halogen anions of beryllium, which is characterized in that it comprises the following steps: preparing BeF capable of producing super halogen anions 3 - target sample; bombardment target sample with PbF 2 Powder mixing target cone produces BeF 3 - beam current; BeF 3 - The beam is crushed in the tandem accelerator; after passing through the main analysis magnet 9 be 2+ into the removable Faraday cup for measurement, 10 be 2+ passing along the main beamline; 10 be 2+ Directly through the main electrostatic analyzer and the second magnet at the high energy end, and finally into the gas detector for analysis. The benefit of the present invention is that: with BeF 3 - as 10 The extraction beam measured by Be-AMS effectively suppresses the 10 The interference of B makes it unnecessary to use the energy-reducing film for secondary stripping at the high-energy end of the small AMS, resulting in 10 The transmission efficiency of the Be beam is guaranteed (up to 100% transmission at the high-energy end), and the original good beam quality is maintained without the membrane; it effectively avoids the high toxicity of BeO as airborne dust to the experimenters. risks of.

The invention provides an accelerator mass spectrometry device based on a low energy dispersion RFQ accelerator and a corresponding accelerator mass spectrometry 14C measurement method, belonging to the technical field of accelerator mass spectrometry. The accelerator mass spectrometry device includes: an ion source, a buncher, an RFQ accelerator, an electron stripper, a high-energy analysis system, and a detector, the above components are connected in sequence, and the RFQ accelerator accelerates 14C, 12C, and 13C ions to a certain energy to carry out electron analysis. Stripping to remove molecular ion interference. The invention uses a low-energy-dispersion RFQ acceleration structure as the ion acceleration device in the 14C measurement accelerator mass spectrometry (AMS) system, and realizes the alternate acceleration of 14C, 12C, and 13C ions by alternately changing the RF power fed into the RFQ accelerator. There is no need for steel cylinders, insulating gas, alternate injection systems, etc. in traditional AMS, and the overall structure is simplified.

The invention discloses an accelerator mass spectrometry carbon-14 dating and sampling device, and belongs to the technical field of radiocarbon (<14>C) dating. The device comprises a CO2 generation and purification apparatus and a graphite synthesis apparatus, wherein, a reactor of the CO2 generation and purification apparatus comprises a vacuum joint, a quartz tube, a quartz tube cutter, an airbottle and a ball valve; the vacuum joint is provided with four interfaces, the upper interface is connected with the ball valve, the rear interface is connected with a pressure sensor, the front interface is movably connected with the air bottle, the lower interface is connected with the quartz tube or the quartz tube cutter; and the reactor of the graphite synthesis apparatus comprises the two quartz tubes, a vacuum joint and a ball valve, the vacuum joint is also provided with four interfaces, wherein, the upper interface is connected with the ball valve, the rear interface is connected with a pressure sensor, and the lower interface and the front interface are respectively connected with two quartz tubes. The device is applicable to preparing a small graphite target sample, and the obtained target material has excellent performance.

A method of removing nuclear isobars from a mass spectrometric technique comprising directing ions, decelerating the ions, neutralizing a first portion of the ions, creating residual ions and a second portion of the ions, reionizing a selective portion of the ions, re-accelerating the selective reionized portion of ions, and directing the reionized portion of ions to a detector. An apparatus to remove nuclear isobars comprising a deceleration lens, an equipotential surface, an electron source to neutralize a portion of the ion beam, a deflector pair, a tunable resonance ionization laser for selective resonant reionization, and an acceleration lens.