Fluoride as a chemical modifier for the determination of phosphorus by electrothermal atomic absorption spectrometry

Abstract

The use of HF, NaF, KF, CsF and NH₄F as chemical modifiers for the determination of phosphorus by electrothermal atomic absorption spectrometry is described. All the fluorides studied were found to stabilize the phosphorus atomic absorption signals, allowing for ashing temperatures higher than those with no modifier, without losses of the analyte. The best results using these modifiers were obtained with NaF. However, the sensitivity of the phosphorus signals was lower than when Pd was used as the modifier. The accuracy of the phosphorus determinations using the new NaF modifier was checked by analyses of NIST Standard Reference Materials (SRM 1570 Trace Elements in Spinach, SRM 1571 Orchard Leaves, SRM 1575 Pine Needles and SRM 1577a Bovine Liver)