Recent technological advances that enhance both the resolution and data process capabilities now allow XRF to perform ppm level determinations on a wide range of sample matrices. The primary focus of sample preparation is to achieve homogeneity. Samples are then loaded into a sample cup with a thin mylar film and placed in the instrument. Depending on specific metals, the run time is 10-30 minutes for an energy dispersive system. There are two key advantages to XRF methods.
Sample preparation is generally quick and easy since homogeneity is the primary consideration.
Actual analysis is performed in 10-30 minutes during which the unit may be unattended. XRF is fundamentally an elemental technique operating on the atomic level. Although there are matrix effects that must be compensated for, the actual compound form of the metal is inconsequential to the determination. There are two significant disadvantages to XRF methodologies. As previously indicated, quantitation limits for electrically cooled XRF units are 10-20 ppm with detection limits generally between 2 and 8 ppm.