High-resolution continuum source molecular absorption of the calcium mono-fluoride molecule CaF in a graphite furnace has been used to determine fluorine in tea after acid digestion, alkaline solubilization and preparation of a conventional aqueous infusion. The strongest absorption 'line' of the CaF molecule is at 606.440 nm, which is part of the rotational fine structure of the X(2)Σ(+)-A(2)Π electronic transition; it has a bond dissociation energy of 529 kJ mol(-1), which is comparable with other molecules used for fluorine determination. One advantage of using Ca as the molecule-forming reagent is that spectral interferences are extremely unlikely in the spectral range of its strongest absorption. Another advantage is that Ca acts both as molecule forming reagent and chemical modifier, so that no other reagent has to be added, making the method very simple. The only disadvantage is that Ca has a somewhat negative influence on the graphite tube lifetime. The limit of detection was found to be 0.16 mg L(-1) F, corresponding to 1.6 ng F absolute, and the calibration curve was linear in the range between 0.5 and 25 mg L(-1) with a correlation coefficient of R=0.9994. The results obtained for a certified tea reference material were in agreement with the certified value on a 95% confidence level. There was also no difference between the results obtained after an acid digestion and an alkaline solubilization for 10 tea samples, based on a paired t-test. The values found in the 10 samples ranged between 42 μg g(-1) and 87 μg g(-1) F; the tea infusions contained between 21 μg g(-1) and 56 μg g(-1) F, with an extraction rate between 48% and 74%.

UV‐based technologies have been proposed for the treatment of wastewater containing bisphenol A (BPA), a toxic, endocrine‐disruptor pollutant. Nevertheless, the evaluation of the role of process variables through experimental design has not been previously addressed. In this study, the effects of BPA and H2O2 initial concentrations, and specific photon emission rate (EP,0) on BPA degradation by the UV and UV/H2O2 processes were investigated, using the Doehlert design and response surface analysis. The experiments were performed in a tubular reactor equipped with a 254‐nm UV lamp, for [H2O2]0 and EP,0 in the ranges 1.6–9.6 mmol · L−1 and 0.87 × 1018–3.6 × 1018 photons · L−1 · s−1, respectively. Photolysis ([BPA]0 = 10–50 mg · L−1) was shown to be inefficient for BPA degradation and mineralization, with pollutant removals lower than 55 %. The specific BPA photolysis rate and BPA removal decreased with increasing [BPA]0. In contrast, all the UV/H2O2 experiments ([BPA]0 = 50 mg · L−1) resulted in total BPA degradation after 60 min of irradiation. In this case, the best conditions were [H2O2]0 = 7.6 mmol · L−1 and Ep,0 = 3.6 × 1018 photons · L−1 · s−1, achieving the highest BPA degradation rate and removal after 15 min, and the second highest TOC removal after 180 min. In most experiments less than 75 % TOC removal was achieved, with 95 % mineralization observed solely for the highest [H2O2]0 and EP,0. In any case, the residual toxicity and endocrine activity of treated solutions must be determined, in order to prove the applicability of the UV/H2O2 process for real water and wastewater treatment.

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