Pressed Pellet Analysis (PP)

PP method is suitable to analyze the elemental composition of pelletized samples with flat surface area to obtain higher accuracy.

Recommendation

  • 7 – 10 g of a dry powdered sample of < 250 μm size fraction is preferred. If samples are delivered wet and bulky, additional preparation steps (drying, grinding, or sieving) prolong the analysis, and an extra charge is applied (see the XRF Sample Preparation rate on the Pricing, Billing, and Payment page).
  • The average turnaround time is two weeks per 10 samples.

Methodology

The sample is dried at 105 °C overnight and sieved to < 250 μm. The sample is mixed with the SPEX paraffin binder 3646 (9:1 ratio) in a Chemplex Industries, Inc. SpectroVial Grinding Vial (Cat # 1134) with two Chemplex Industries, Inc. Ball Pestles (Cat # 1211) using a SPEX mixer mill. 4 g of the mixture is hydraulically pressed into a 32 mm pellet at 10 tons of pressure and analyzed by a Rigaku NEX CG Energy-Dispersive X-Ray Fluorescence (EDXRF) spectrometer under vacuum. The automatic sample changer accommodates thirteen specimens and two standards.

Results

Semi-quantitative analyses are obtained using Rigaku’s RPF-SQX (Rigaku Profile Fitting-Spectra Quant X) software combine with the FP (fundamental parameters) method. The LLD or LOD are determined by the software. The final report includes the content of Na, Mg, Al, Si, P, S, K, Ca, Ti, Mn, and Fe oxides in wt. percentages, and concentration of other elements in ppm.

Quality Assurance (QA) and Quality Control (QC)

Precision and accuracy are determined by analyzing sample duplicates as well as certified reference materials from the National Institute of Standards & Technology (NIST).