Abstract: A nuclear magnetic resonance (NMR) method for detecting hydrogen peroxide includes stimulating a spin signal in a liquid sample in a static magnetic field by exciting the sample with a first electromagnetic pulse having a frequency corresponding to a hydrogen NMR frequency; after a first time period, refocusing the spin signal by a series of second electromagnetic pulses also having the NMR-corresponding frequency and separated by a first echo time, while sampling a first train of spin signals; and refocusing the spin signal by a series of third electromagnetic pulses having the NMR-corresponding frequency and separated by a second echo time while sampling a second train of spin signals, the second echo time different from the first echo time. First and second spin-spin relaxation times are derived from the trains of spin signals, and a quotient of the spin-spin relaxation times indicates the presence of hydrogen peroxide.

Abstract: A magnet arrangement includes (a) a first and a second head ring magnet each having a substantially circular geometry with respect to a center axis and (b) a central ring magnet having a substantially circular geometry with respect to a center axis. The central ring magnet is disposed between the first and second head ring magnet in direction of the center axis. At least one of the magnets includes a first number of first magnets having at least one trapezoidal cross section and a second number of second magnets having at least one rectangular cross section. The second magnets are disposed in between the first magnets in circumferential direction. With this geometrical arrangement, magnets having a trapezoidal cross section include a guidance for a magnet having a rectangular cross section allowing the movements in radial direction of these last magnets.

Abstract: An apparatus for providing a sensitive volume for single-sided NMR includes: (i) at least one first permanent magnet for providing a first magnetic field at the sensitive volume; and (ii) at least one of the following means for superimposing at least one second magnetic field for homogenizing the first magnetic field in the sensitive volume: (A) at least one shim magnet, (B) at least one pair of shim magnets, and (C) at least one electrical conductor being connectable to an electric current source. The at least one second magnetic field is adjusted such that the magnetic field homogeneity in the sensitive volume is corresponding to a line width of hydrogen (1H) of less than 10 ppm.

Abstract: A nuclear magnetic resonance (NMR) method for detecting hydrogen peroxide includes providing a liquid sample in a static magnetic field; stimulating a spin signal in the sample by exciting the sample with a first electromagnetic pulse having a frequency corresponding to the hydrogen NMR frequency in the static magnetic field; waiting for a first time period; refocusing the spin signal in the sample for a first number of times by a series of second electromagnetic pulses having a frequency corresponding to the hydrogen NMR frequency in the static magnetic field, said second electromagnetic pulses being separated by a first echo time, while sampling a first train of spin signals in between the second electromagnetic pulses; and refocusing the spin signal in the sample for a second number of times by a series of third electromagnetic pulses having a frequency corresponding to the hydrogen frequency in the static magnetic field, said third electromagnetic pulses being separated by a second echo time while samplin

Abstract: An apparatus for providing a sensitive volume for single-sided NMR includes: (i) at least one first permanent magnet for providing a first magnetic field at the sensitive volume; and (ii) at least one of the following means for superimposing at least one second magnetic field for homogenizing the first magnetic field in the sensitive volume: (A) at least one shim magnet, (B) at least one pair of shim magnets, and (C) at least one electrical conductor being connectable to an electric current source. The at least one second magnetic field is adjusted such that the magnetic field homogeneity in the sensitive volume is corresponding to a line width of hydrogen (1H) of less than 10 ppm.

Abstract: A magnet arrangement includes (a) a first and a second head ring magnet each having a substantially circular geometry with respect to a centre axis and (b) a central ring magnet having a substantially circular geometry with respect to a centre axis. The central ring magnet is disposed between the first and second head ring magnet in direction of the centre axis. At least one of the magnets includes a first number of first magnets having at least one trapezoidal cross section and a second number of second magnets having at least one rectangular cross section. The second magnets are disposed in between the first magnets in circumferential direction. With this geometrical arrangement, magnets having a trapezoidal cross section include a guidance for a magnet having a rectangular cross section allowing the movements in radial direction of these last magnets.

Abstract: A low-cost single-sided NMR sensor to produce depth profiles with microscopic spatial resolution is presented. The open geometry of the NMR sensor provides a non-invasive and non-destructive testing method to characterize the depth structure of objects of arbitrary size. The permanent magnet geometry generates one plane of constant magnetic field intensity parallel to the scanner surface. By combining the highly uniform static gradient with selective RF excitation, a thin flat sensitive slice can be defined. By moving the relative position between the slice and the object, one-dimensional profiles of the near surface of large samples are produced with high spatial resolution.

Abstract: A low-cost single-sided NMR sensor to produce depth profiles with microscopic spatial resolution is presented. The open geometry of the NMR sensor provides a non-invasive and non-destructive testing method to characterize the depth structure of objects of arbitrary size. The permanent magnet geometry generates one plane of constant magnetic field intensity parallel to the scanner surface. By combining the highly uniform static gradient with selective RF excitation, a thin flat sensitive slice can be defined. By moving the relative position between the slice and the object, one-dimensional profiles of the near surface of large samples are produced with high spatial resolution.