Soil and Sediment Wavelength Dispersive X-ray Fluorescence Spectrometry (1)

(1) Scope of application

HJ780-2015 stipulates the wavelength dispersive X-ray fluorescence spectrometry for the determination of 25 inorganic elements and 7 oxides in soil and sediment

The detection limit of 22 inorganic elements is 1.

Table 5-55 Method detection limits and lower limit of determination for 25 inorganic elements and 7 oxides

Note: In the table, the unit of detection limit and lower limit of determination of elements is mg/kg; the unit of detection limit and lower limit of determination of oxides is %

(2) Method principle

After the soil or sediment samples are pressed by pads or aluminum rings (or plastic rings), the atoms in the samples are excited by appropriate high-energy radiation, and the characteristic X-rays of the atoms are emitted.

(3) Interference and elimination

(1) The X-ray fluorescence intensity value generated by the atoms of the element to be measured in the sample excited by radiation is related to the content of the element and the mass absorption coefficient of the primary spectrum

(2) The uniformity and surface characteristics of the sample will affect the measurement strength of the analysis line.

(3) Use interference correction coefficients to correct spectral line overlap interference

(4) Reagents and materials

(1) Boric acid (H ₃ BO ₃ ): analytically pure

(2) High-density and low-pressure polyethylene powder: analytically pure

(3) Standard samples: soil, sediment, containing commercially available certified reference materials or standard samples for the determination of 25 inorganic elements and 7 oxides

(4) Plastic ring: inner diameter 34mm

(5) Argon-methane gas: P10 gas, 90% argon + 10% methane

(5) Instruments and equipment

(1) X-ray fluorescence spectrometer: wavelength dispersion type, with computer control system

(2) Powder tablet press: Max Leli 40 tons

(3) Analytical balance: accuracy of 0.

(4) Sieve: non-metallic sieve with an aperture of 0.
075mm and 200 mesh
.