XRF analysis - some sensitivity comparisons between charged-particle and photon excitation

A comparison is made between the limits of detection for trace elements when charged-particle and photon excited X-ray fluorescence analysis are performed on a specific type of sample (5 mg/cm2 organic based). Large-scale analysis (approximately 30 000 samples per year) at levels of 1 ppm or lower is shown to be practical with either technique when well executed. Determining the physical reason for unexplained detector background is shown to be very important particularly for the potential improvement that might be realized in photon-excited analysis applications. (Auth.)