Total reflection X-ray fluorescence spectrometer (TXRF) is a high-sensitivity analytical instrument based on total reflection X-ray fluorescence technology, mainly used for quantitative and semi quantitative multi-element trace analysis of liquids, suspensions, solids, and pollutant samples.
When X-rays are incident on the surface of a sample carrier (such as a quartz plate) at angles less than the critical angle (usually 0.1 ° -0.5 °), total reflection occurs to avoid absorption and scattering of X-rays by the carrier. The element atoms in the sample (uniformly spread on the surface of the carrier, thickness ≤ 100nm) are excited and emit characteristic X-ray fluorescence (XRF). The energy and intensity of the characteristic X-rays are collected by a detector, and the element type is identified based on the energy. The element content is quantitatively calculated based on the intensity.
Its core functions include:
Multi element microanalysis: It can simultaneously perform quantitative or semi quantitative detection of constant, secondary, and trace elements in samples such as liquids, powders, and solids, covering the range of elements from aluminum (Al) to uranium (U) (except for inert gases and a few elements), with detection limits as low as nanograms (ng) or even sub nanograms.
Reduce background noise: By illuminating the sample at a very small incident angle (usually below 0.1 °), the total reflection phenomenon is utilized to significantly reduce substrate scattering interference, reducing the detection limit by several orders of magnitude compared to conventional X-ray fluorescence techniques and improving the signal-to-noise ratio.
Widely applicable sample types: No need for complex sample preparation, can directly analyze micro upgraded liquid, powder or solid samples, especially suitable for non-destructive testing of ultra trace samples (such as biological samples, environmental pollutants).
Instrument structure
X-ray source: composed of a high-voltage generator and a radiation tube, providing primary X-rays to excite the elements to be measured in the sample.
Optical path system: including aperture, filter, collimating slit, monochromator, etc., used to adjust the geometric shape and spectral distribution of primary X-rays to meet the requirements of TXRF's incident angle, energy distribution, etc.
Sample injection system: Provides sample carriers, mostly quartz glass, organic glass, etc., to meet total reflection conditions and complete automatic injection operations.
Detector: As the core component for data readout, there are mainly semiconductor detectors, silicon drift detectors (SDD), and position sensitive detectors. Currently, silicon drift detectors are commonly used in commercial instruments.
Data processing system: Analyze and process the data collected by the detector, calculate the types and contents of elements, and present the results in the form of charts and other forms.