A micromethod for the determination of fluoride in blood plasma and saliva

A simple and accurate technique for the determination of fluoride (F−) in capillary-sampled blood is presented. The method is based on the known addition-slope determination technique using the fluoride electrode is required. A standard deviation of 1.3–5.6% in the range 300–10 ng F/ml was given by 259 duplicate determinations on human plasma. Measurements of parotid saliva showed that it was possible to analyze fluoride concentrations as low as 4 ng F/ml with good reproducibility. The results also show that a 150 μl sample is sufficient for fluoride determination with high accuracy. This method can easily be used in a clinical laboratory.