摘要:
A method is described for determination of the content of at least one component of a sample by means of a nuclear magnetic resonance pulse spectrometer, with the magnetization of the sample being influenced by a sequence of radio-frequency pulses such that the signal amplitudes to be observed can be determined. The magnetization of the sample is initially saturated, and the signal amplitudes which are determined at each time by the longitudinal and transverse relaxation times T1 and T2 and/or T2* and/or T1p, from which a value for the content of the at least one component is determined, are measured at the same time in a cohesive experimental procedure.
摘要:
A method and an apparatus for investigating the imperishability of n liquid foodstuffs using electron spin resonance (ESR) exposes samples of the foodstuffs to an elevated temperature for an extended time-period. At predetermined intervals during the period, the intensity of an ESR signal of each sample is measured and plotted vs. time in a diagram for that sample. The time of a superproportional increase in intensity is detected for each foodstuff. The number n of different foodstuffs is determined by dividing the predetermined interval by the measurement time. The n samples are investigated simultaneously by sequentially cycling the n samples through a common sample vessel. Each time, the intensity of the ESR signal of the sample is measured and then plotted in a diagram unique to that foodstuff. The sequence of foodstuffs are cycled through the sample vessel until a predetermined number m of measuring points per foodstuff has been attained.
摘要:
A resonator apparatus and a method for electron spin resonance (ESR) measurements are disclosed. The resonator apparatus comprises a dielectric resonator and a sample vessel extending through the resonator. The sample vessel is configured as one single flexible tube. Means are provided for conveying a liquid sample substance through the flexible tube. According to the method a liquid sample substance is guided through the sample vessel, wherein the sample substance is gated by cyclically conveying and stopping, resp., a flow of the sample substance. A measurement is conducted within the resonator when the flow of sample substance is stopped.
摘要:
A method and an apparatus serve the purpose of determining the fat or oil content of a sample. The sample is dried under the action of a microwave field and is examined under the action of a radio-frequency signal and of a constant magnetic field by means of nuclear magnetic resonance. The sample is exposed to the microwave field, the radio-frequency signal and the magnetic field at the same measuring place in a common measuring chamber. The apparatus has a microwave source for drying the sample, a magnetic system for generating a nuclear magnetic resonance magnetic field in the sample, and a nuclear magnetic resonance measuring arrangement for irradiating radio-frequency signals into the sample and for receiving excited nuclear magnetic resonance signals from the sample. The microwave source, the magnetic system and the nuclear magnetic resonance measuring arrangement are connected to a common measuring chamber in which the sample is located.
摘要:
A method and an apparatus serve the purpose of determining the fat or oil content of a sample. The sample is dried under the action of a microwave field and is examined under the action of a radio-frequency signal and of a constant magnetic field by means of nuclear magnetic resonance. The sample is exposed to the microwave field, the radio-frequency signal and the magnetic field at the same measuring place in a common measuring chamber. The apparatus has a microwave source for drying the sample, a magnetic system for generating a nuclear magnetic resonance magnetic field in the sample, and a nuclear magnetic resonance measuring arrangement for irradiating radio-frequency signals into the sample and for receiving excited nuclear magnetic resonance signals from the sample. The microwave source, the magnetic system and the nuclear magnetic resonance measuring arrangement are connected to a common measuring chamber in which the sample is located.
摘要:
A method is described for determination of the content of at least one component of a sample by means of a nuclear magnetic resonance pulse spectrometer, with the magnetization of the sample being influenced by a sequence of radio-frequency pulses such that the signal amplitudes to be observed can be determined. The magnetization of the sample is initially saturated, and the signal amplitudes which are determined at each time by the longitudinal and transverse relaxation times T1 and T2 and/or T2* and/or T1p, from which a value for the content of the at least one component is determined, are measured at the same time in a cohesive experimental procedure.
摘要:
A probehead for an electron spin resonance (ESR) dosimeter comprises a resonator and an insert extending into the resonator. The insert has a guide channel for bringing a sample into the resonator. The sample comprises a dosimeter substance. The guide channel is configured for receiving and guiding a test strip. The insert is provided with a first machine-readable code imprint. The insert is provided with at least one reference sample. A pressurized air unit is provided for blowing the sample out of the resonator after completion of a measurement. The insert has an opening on an upper side of the resonator. The opening is openly accessible for manually inserting dosimeter pills thereinto. The insert, further, is provided on the upper side with a pressurized air connector. The pressurized air connector is connected to an orifice via a pressurized air channel within the insert. The orifice is located within a lower, otherwise closed bottom of the guide channel. The sample substance comprises a chromium-doped magnesium oxide (Cr:MgO). The magnesium oxide is doped with the isotope 52Cr.
摘要:
An analysis system (1) for the analysis of a sample, comprises a gel permeation chromatograph (14) that is coupled with a nuclear magnetic resonance (=NMR) spectrometer. The chromatograph (14) has a gel permeation chromatography (=GPC) separating column system (6a) that is filled with porous particles (21). The NMR spectrometer is configured as a low-field NMR spectrometer (8) with a permanent magnet system (9) for generating a B0 field of the NMR spectrometer. The low-field NMR spectrometer (8) comprises a shim system (10) with which homogeneity of the B0 field of at least 0.5 ppm can be achieved in a right circular cylindrical sample volume (27) having a diameter of at least 5 mm and a length of at least 15 mm. The system permits the quantitative and qualitative chemical analysis of samples containing substances of different molecular size using a less expensive apparatus.
摘要:
An analysis system (1) for the analysis of a sample, comprises a gel permeation chromatograph (14) that is coupled with a nuclear magnetic resonance(=NMR) spectrometer. The chromatograph (14) has a gel permeation chromatography(=GPC) separating column system (6a) that is filled with porous particles (21). The GPC separating column system (6a) includes at least the one GPC separating column (6), the GPC separating columns (6) of the GPC separating column system (6a) having an overall combined internal volume of at least 45 cm3, preferably at least 100 cm3. The NMR spectrometer is configured as a low-field NMR spectrometer (8) with a permanent magnet system (9) for generating a B0 field of the NMR spectrometer. The low-field NMR spectrometer (8) comprises a shim system (10) with which homogeneity of the B0 field of 0.5 ppm or better, preferably 0.1 ppm or better, can be achieved in a right circular cylindrical sample volume (27) having a diameter of at least 5 mm and a length of at least 15 mm. The low-field NMR spectrometer (8) further comprises a lock function (29) to compensate for a drift of the B0 field. The invention permits the quantitative and qualitative chemical analysis of samples containing substances of different molecular size with less expensive apparatus.