Determination of Phosphorus in Hydrogenation Catalyst by Single Wavelength X-Ray Fluorescence Spectrometry

A method for the determination of phosphorus in hydrogenation catalyst by single wavelength X-ray fluorescence spectrometry was established. The sample powder of dry catalyst (0.200 0 g) was placed into a silver crucible, and 10 mL of 0.67 g·mL^-1 sodium hydroxide solution was added. The above mixture was heated to boil for 20 min, and transfered to a 250 mL beaker while it was hot. Then 10 mL of 50% (φ) sulfuric acid solution was added to adjust the system acidity, and heated until the sample was completely dissolved. The solution was made its volume up to 250 mL after cooling, and 6 mL of the above test solution was taken. The content of phosphorus was determined with a Phoebe single wavelength X-ray fluorescence phosphorus analyzer with measured time of 600 s. The results showed that linear relationship between fluorescence intensity and mass fraction of phosphorus was found within 0.006%, with detection limit (3s/k) of 0.4 μg·g^-1. Test for recovery was made by standard addition method, giving results in the range of 93.0%-120%, with RSDs (n=7) of the determined values less than 5.0%. The results obtained by this method were consistent with those obtained by classical spectrophotometry.