• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.367-368
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• 2016

본 연구는 임상에서 사용되어지는 두 가지의 불소 바니쉬를 비교연구 하였다. 또한 각각 치아표면에 10mg의 불소 바니쉬를 도포하였다. 각 대상자들의 타액의 불소이온유리농도는 1,3,12,24시간으로 채취하여 분석하였다. 각각의 불소 바니쉬를 도포한 타액 내 불소이온의 유리 누적량은 차이를 보였다. 본 연구는 현재 사용되어지는 불소 바니쉬를 선택함에 있어 기초자료로 사용될 수 있을 것이라 사료되어진다.

• Clean Technology
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• v.20 no.1
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• pp.51-56
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• 2014

In this study, PSf-$Al(OH)_3$ beads were prepared by immobilizating aluminum hydroxide $Al(OH)_3$ with polysulfone (PSf). The removal experiments of the fluoride ions by PSf-$Al(OH)_3$ beads were conducted batchwise and the parameters such as pH, initial fluoride concentration, and coexisting ions were investigated. The maximum removal capacity obtained from Langmuir isotherm was 52.4 mg/g and the optimum pH region of fluoride ions was in the range of 4 to 10. The removal process of fluoride ions by PSf-$Al(OH)_3$ beads was found to be controlled by both external mass transfer at the earlier stage followed by internal diffusion at the later stage. The presence of coexisting anions such as $HCO_3{^-}$, $SO{_4}^{2-}$, $NO_3{^-}$, and $Cl^-$ had a negative effect on removal of fluoride ions by PSf-$Al(OH)_3$ beads.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.235-241
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• 2018

In this study, total fluoride (TF) in commercial toothpastes for children in Korea was evaluated and compared with the fluoride concentration declared by the manufacturer (Declared F). Additionally, total soluble fluoride (TSF) was evaluated and compared with TF. Ten toothpastes were coded with letters to allow blind analysis. For evaluation of TF, each toothpaste was homogenized in deionized water. For evaluation of TSF, each toothpaste was centrifuged and then, the supernatant of the sample was evaluated. Fluoride concentrations were assessed using a fluoride electrode coupled to an ion analyzer. Only one toothpaste showed lower TF concentration than Declared F. In all toothpastes, TSF was similar to the TF.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.61-64
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• 1977

Fluoride analysis using fluoride specific ion electrode has been carried out from sea water samples at 15 stations in the west coast of Korea. The concentration was varied from 0.83 to 1.00 ppm; ratio to chlorinity ranged from 4.60 to $5.48\times10^{-5}$. There was a tendency that the ratio to chlorinity was increased with the depth. In general the concentration was less than that of other seas.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.19-24
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• 2018

Water quality is affected by the pollutants flowing into rivers since the interaction between water bodies and sediments in various environmental conditions. Especially, accumulation of sediments increases in the stagnant water areas due to a relative long hydrological retention time in the water bodies. Therefore, it is an important factor of water quality to understand characterization of the material behavior in water bodies and sediments. In this study, the objective of the conditional experiments was small and medium sized streams located in Gyeonggi-do. To estimate how the changes of fluoride behavior, depending on the pH, ion type, concentration, and clay contents. The pH results showed a trend that adsorption amount of fluorine decreased and the dissolution of fluorine increased following by pH increasing. The concentration and type of ions results showed that $Cl^-$ and $SO{_4}^{2-}$ ions had no significant effect on the adsorption ability of fluorine, the amount of dissolution was increased because $OH^-$ ion had active competition with fluorine in the reaction. The ingredient of sediment results showed that the amounts of fluoride adsorption and dissolution were reduced in samples, which contain relatively large amounts of Silt and Clay components. This means that the environmental conditions of water bodies greatly affect the adsorption and dissolution of fluoride in the sediments, so that proper management of fluoride in the sediments must precede an understanding of the environmental conditions of the water bodies.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.19-22
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• 1988

For decreasing the level of fluoride content in Antarctic krill, the changes of the content in solubel protein from the krill muscle depended on pH, ion species and ionic strength of the extracting solutions were investigated. The content of total fluoride of boiled muscle was higher than that of raw material, and the portions of fluoride with ionic form to the total content were 70% and 49%, respectively. In the effect of pH, fluoride contents of soluble protein from raw and boiled muscle showed the lowest values near 10. The effective ionic strength for decrease of fluoride content was 0.05M as NaCl at pH 11, and the content in the protein from raw material in this conditions was about 8 ppm.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.92-98
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• 2015

In this study, phenol-based activated carbons (ACs) were fluorinated at various fluorine partial pressures (0.01~0.03 MPa) and the $Cr^{6+}$ ion adsorption of fluorinated ACs was investigated. According to BET and XPS results, the specific surface area and total pore volume of fluorinated ACs increased by 24.7 and 55.8%, respectively, and fluorine functional groups were introduced to AC surface. The most optimized condition of $Cr^{6+}$ ion adsorption was confirmed at the fluorine partial pressure of 0.02 MPa. And also the removal efficiency of $Cr^{6+}$ ion was up to 98% at 300 mg/L of the initial concentration, and these results showed an approximately three-fold increase compared to that of using untreated ACs. Furthermore, the $Cr^{6+}$ ion adsorption of fluorinated ACs was completed in less than 30 min in contrast with untreated ACs, which was expected to be an increase of the affinity between $Cr^{6+}$ ions and ACs surfaces by fluorination.

• Journal of the Korean Chemical Society
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• v.51 no.3
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• pp.258-264
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• 2007

Novel fluoride sensory systems have been successfully developed. Previously developed method of the fluoride-induced lactonization to fluorescent molecules was detailed, and newly developed fluoride-induced aromatic cyclization scheme was introduced. Based on the strategies using the specific affinity of fluoride to silicon, our systems are highly selective for fluoride ion. Incorporation of the developed sensor to a conjugated polymer has successfully enhanced its sensitivity to fluoride ion.

• Analytical Science and Technology
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• v.27 no.6
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• pp.333-338
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• 2014

A simple and sensitive analytical method for fluoride in urine by ion selective electrode (ISE) method was presented. Traditional buffer for fluoride determination using ISE is acetate-based one. Researchers have pointed out some drawbacks of the buffer for fluoride ISE analysis, and some other buffers including citrate-ammonium buffer and MES buffer have been studied for accurate determination of fluoride in urine here. These buffers provided promising results in environmental field, and this author focused on overcoming the interference of co-existing aluminium. The results show that MES-CyDTA buffer gave the best recovery with accuracy of 95-97.5% and precision of 1.9-7.9% for reference sample of 1.8-7.8 mg/L fluoride in urine, with smaller amount of samples and shorter analysis time compared with the traditional method which used acetate buffer. The method was applied to field samples, and which showed urinary of $0.98{\pm}0.38mg/g$ creatinine for workers in electric cable manufacturing factory (n=15) and $0.59{\pm}0.30mg/g$ creatinine for non-exposed workers (n=12).

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.247-252
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• 2005

The typical treatment method for fluoride polluted water is the flocculation and precipitation method which usually is capable of reducing the fluoride concentration down to the level of about 10 ppm. However, this method is no longer effective for the treatment of contaminated water having less than 10 ppm of fluorides. To remove fluorides in polluted water from the fluoride concentration between 1 to 10 ppm, several adsorbents were prepared mainly based on an activated alumina and the fluoride removal efficiencies of the adsorbents were analyzed. The best fluoride removal efficiency was obtained when the activated alumina treated by sulfuric acid was used as the adsorbent. A proper calcination temperature for the sulfuric acid contained activated alumina was found to be about $500^{\circ}C$. An adsorption isotherm for the adsorbent was also obtained by using Freundlich model. The values of the constants in Freundlich isotherm model were calculated to be K=6.63 and 1/n=0.29 based on the results obtained from the series of batch type adsorption experiments.