Increasing Fluoride Concentration Research Articles

Concentration of Fluoride in Cow's and Buffalo's Milk in Relation to Varying Levels of Fluoride Concentration in Drinking Water of Mathura City in India- A Pilot Study.

To estimate fluoride concentration in drinking water, cow's milk and buffalo's milk and to correlate the concentration of fluoride in cow's milk and buffalo's milk with varying levels of fluoride concentration in drinking water. Ten households having both cows and buffalo's were selected by convenience in each of the 3 zones (below optimum fluoride <0.7 ppm (parts per million), optimum fluoride 0.7-1.2 ppm and above optimum fluoride areas > 1.2 ppm). From these selected households, 200 ml of fresh milk of both cows and buffaloes was collected along with 200 ml of drinking water for estimation of fluoride concentration by using a fluoride ion selective electrode method. The data was analysed using SPSS, version 11.5 for windows. The mean fluoride concentration of drinking water, cow's milk and buffalo's milk in three different fluoride zones was 0.89±0.39, 0.09±0.07, 0.09±0.08 respectively. Pearson's correlation found a statistically significant correlation between fluoride concentrations in cow's and buffalo's milk with varying levels of fluoride concentration in drinking water in zone B and zone C. However, this correlation was not statistically significant in zone A. With an increase in fluoride concentration in drinking water there was an increase in concentration of fluoride in cow's and buffalo's milk. We conclude that this association is seen in conjunction to not only a single factor but rather due to culmination of several other aspects. So, there is a need to elucidate the other factors that might be contributing to this increase and dental fluorosis.

Surface complexation of fluoride at the activated nano-gibbsite water interface

The drawbacks of existing fluoride removal processes are due to low efficiencies and less mechanistic understanding of the process. The acid–base protolysis and surface complexation constants for fluoride and thermally activated nanogibbsite were investigated in this study for the first time. Fluoride adsorption on heat activated gibbsite nanoparticles (HGNP) was determined as a function of pH, concentration of background electrolyte and adsorbate loading. XRD evidenced the HGNP is in a transient state of the formation of χ-alumina as a poorly crystalline solid. An immense increase in surface area was obtained from 50 to 399m2/g by the heat activation. Macroscopic data obtained from the batch experiments suggested an enhanced fluoride removal by HGNP with an adsorption maximum around pH 6. The adsorption quantified by the diffuse double layer surface complexation model indicated an inner sphere complexation mechanism at 0.526mM of F̄ with monodentate mononuclear complexes. An increase of fluoride concentration to 1.351mM demonstrated a multilayer complex formation which was also confirmed by the isotherm data modeling with two distinct sorption maxima. XPS evidenced similar results showing two peaks at 684.7 and 688.5eV for weak and strong bonded fluoride on HNGP surface. Fluoride adsorption maximum was reported as 4×10−6mol/m2 based on Langmuir data fitting.

Fluoride affects calcium homeostasis and osteogenic transcription factor expressions through L-type calcium channels in osteoblast cell line.

Osteoblast L-type voltage-dependent calcium channels (VDCC) play important roles in maintaining intracellular homeostasis and influencing multiple cellular processes. In particular, they contribute to the activities and functions of osteoblasts (OBs). In order to study how L-type VDCC modulate calcium ion (Ca(2+)) homeostasis and the expression of osteogenic transcription factors in OBs exposed to fluoride, MC3T3-E1 cells were exposed to a gradient of concentrations of fluoride (0, 2.0, 5.0, 10.0 mg/L) in combination with 10 μM nifedipine, a specific inhibitor of VDCC, for 48 h. We examined messenger RNA (mRNA) and protein levels of Cav1.2, the main subunit of VDCC, and c-fos, c-jun, runt-related transcription factor 2 (Runx2), osterix (OSX), and intracellular free Ca(2+) ([Ca(2+)]i) concentrations in MC3T3-E1 cells. Our results showed that [Ca(2+)]i levels increased in a dose-dependent manner with increase in concentration of fluoride. Meantime, results indicated that lower concentrations of fluoride (less than 5 mg/L, especially 2 mg/L) can lead to high expression of Cav1.2 and enhance osteogenic function, while high concentration of fluoride (10 mg/L) can induce decreased Cav1.2 and osteogenic transcriptional factors in MC3T3E1 cells exposed to fluoride. However, the levels of [Ca(2+)]i, Cav1.2, c-fos, c-jun, Runx2, and OSX induced by fluoride were significantly altered and even reversed in the presence of nifedipine. These results demonstrate that L-type calcium channels play a crucial role in Ca(2+) homeostasis and they affect the expression of osteogenic transcription factors in fluoride-treated osteoblasts.

Influences of natural and anthropogenic factors on surface and groundwater quality in rural and urban areas

Although water constitutes 71% of the earth's surface, only 0.3% of it is available as fresh water for human use. Moreover, the quality of fresh water in ground and surface systems is of great concern, as potable water needs to have appropriate mineral content. Ground and surface water quality in rural and urban environments is affected by both natural processes and anthropogenic influences. Because of this, water is becoming scarcer as the population increases across the world. Natural processes leading to changes in water quality include weathering of rocks, evapotranspiration, depositions due to wind, leaching from soil, run-off due to hydrological factors, and biological processes in the aquatic environment. These natural processes cause changes in the pH and alkalinity of the water, and also phosphorus loading, increase in fluoride content and high concentrations of sulphates. Anthropogenic factors affecting water quality include impacts due to agriculture, use of fertilizers, manures and pesticides, animal husbandry activities, inefficient irrigation practices, deforestation of woods, aquaculture, pollution due to industrial effluents and domestic sewage, mining, and recreational activities. These anthropogenic influences cause elevated concentrations of heavy metals, mercury, coliforms and nutrient loads. This paper studies the effects of natural processes and human influences in rural and urban aquatic systems. Pollution due to environmental parameters such as heavy metal pollution, heavy metals and bacterial and pathogenic contamination of both urban and rural areas is discussed in detail.

Expression of ERK and p-ERK proteins of ERK signaling pathway in the kidneys of fluoride-exposed carp (Cyprinus carpio)

Chronic exposure to fluoride can result in a variety of adverse effects in fish. Previously we indicated that high fluoride caused damage and apoptosis in the kidneys of the common carp, Cyprinus carpio. In this study, the effects of fluoride on the expression and localization of ERK and p-ERK proteins in the ERK signaling pathway were determined using Western blotting and immunohistochemical methods in the kidneys of carp exposed to 0, 40, 80, 120mg/L fluoride, respectively. Western blotting analysis found that compared with the controls, the levels of ERK1 and ERK2 proteins were relatively unchanged in fluoride-exposed fish, while p-ERK1 and p-ERK2 protein levels decreased significantly with the increased fluoride concentrations. The immunohistochemical analysis found the proteins of ERK and p-ERK were predominantly localized in the cytoplasm of epithelial cells in the renal tubules of C. carpio. Compared with the control group, the levels of ERK protein were relatively constant, yet the levels of p-ERK protein and p-ERK/ERK ratio were reduced with fluoride exposure dose. These findings indicate that the renal damage in carp exposed to fluoride is mediated via the ERK pathway. Fluoride exposure could inactivate ERK, inhibit the expression of p-ERK protein, and induce renal damage in C. carpio.

Effect of fluoride doping on impedance spectra of barium strontium titanate glass ceramics

A system of barium strontium titanate glass ceramics with different fluoride concentrations were prepared by melt-annealing technique. The effect of fluoride doping on impedance spectra of the barium strontium titanate glass ceramics were investigated. According to the impedance spectroscopy studies, three (low, middle, and high frequency) electrical responses, which corresponds to glass phase, crystal–glass interface and crystal interior were identified. It is shown that with the increase of fluoride concentration, the resistivity of the glass phase passed through a minimum and then increased. In addition, the capacitance of the crystal–glass interface increased and the capacitance of the crystal phase decreased with the increase of the fluoride concentration. Moreover, as a result of ac conductivity calculation and analysis, it is believed that the dc conduction was affected by the glass and crystal–glass interface regions and ac regime was attributed to the crystal phase. Based on the results, a change of the compensation mechanism from electronic to ionic one with variation in fluoride concentration was proposed.

Effects of fluoridated milk on root dentin remineralization.

BackgroundThe prevalence of root caries is increasing with greater life expectancy and number of retained teeth. Therefore, new preventive strategies should be developed to reduce the prevalence of root caries. The aim of this study was to investigate the effects of fluoridated milk on the remineralization of root dentin and to compare these effects to those of sodium fluoride (NaF) application without milk.MethodsThirty extracted human molars were divided into 6 groups, and the root cementum was removed from each tooth. The dentin surface was demineralized and then incubated with one of the following six solutions: Sodium chloride NaCl, artificial saliva, milk, milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Serial sections were cut through the lesions and investigated with polarized light microscopy and quantitative morphometry, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The data were statistically evaluated using a one-way ANOVA for multiple comparisons.ResultsThe depth of the lesion decreased with increasing fluoride concentration and was the smallest after incubation with artificial saliva+10 ppm fluoride. SEM analysis revealed a clearly demarcated superficial remineralized zone after incubation with milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Ca content in this zone increased with increasing fluoride content and was highest after artificial saliva+10 ppm fluoride incubation. In the artificial saliva+10 ppm fluoride group, an additional crystalline layer was present on top of the lesion that contained elevated levels of F and Ca.ConclusionIncubation of root dentin with fluoridated milk showed a clear effect on root dentin remineralization, and incubation with NaF dissolved in artificial saliva demonstrated a stronger effect.

Study on Changes of Clinical Indicators and Key Proteins from Fluoride Exposure

Few studies have evaluated the biomarker changes of fluoride exposure. In order to explore early and sensitive indicators, animal experiment was designed. Ninety-six healthy SD rats (48 males and 48 females) weighing approximately 60 g were randomly divided into six groups of 16 animals each by gender average. Control animals were supplied with distilled water only as group 1. Exposure groups' animals were treated with 2, 4, 8, 16, and 32 mg NaF/kg bw, respectively, as groups 2, 3, 4, 5, and 6. Our study found that contents of white blood cell (WBC), lymphocyte percentage (LYMPH%), lymphocyte (LYM), mean platelet volume (MPV), and platelet distribution width (PDW) increased significantly in high-fluoride-exposure groups (p < 0.05), which revealed that immune system may be interfered by high fluoride. Meanwhile, levels of alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), and ALT/AST in groups 5 and 6 decreased significantly compared to those in control group (p < 0.05), as well as the concentration of uric acid (UA) in groups 3, 4, 5, and 6 exhibited the same trends (p < 0.05). On the contrary, the level of blood B2 microglobulin (BB2MG) increased significantly (p < 0.05) in groups 4, 5, and 6. Changes of ALT, AST, UA, and BB2MG suggested the functions of the liver and kidney be altered by fluoride exposure. At the same time, the ATF4 content decreased gradually with the increase of fluoride concentration; furthermore, a highly significant (r = -0.586, p < 0.01) negative relationship between ATF4 content and fluoride exposure level was found. Results meant that clinical indicators cannot act as indicators of high fluoride exposure, and it also suggested that protein ATF4 might be the early and sensitive indicator in epidemiologic study of high fluoride exposure.

Discolouration of glass-ionomer cement at different fluoride concentration levels.

Although application of professionally applied Acidulated Phosphate fluoride (APF) gel is effective in prevention of dental caries, APF-induced discolouration and/or surface degradation of dental restorations has been reported. However, no publication has reported a dose-response effect of APF gel on Glass Ionomer Cement (GIC) restorations in vivo and/or human teeth. Therefore, this study aimed to examine the discolouration effect of APF gel at various concentration levels on GIC restorations of human teeth in vitro. Seventy extracted human teeth were used. Each was restored with GIC and then topically applied with a different dilution of APF gel. Change of shade and/or colour of restorations was assessed by a trained examiner. GIC discolouration was detected on 4 (5.71%) and 23 specimens (32.86%) after the first and the second APF applications, respectively. The discolouration rate increased with APF gel concentration on the second application (χ2=38.314, df=1, p<0.001) but not the first ( χ2=2.352, df=1, p=0.125). Discolouration of GIC restorations was more likely to form under application of a higher concentration of APF gel (OR=1.099, 95%CI=1.052, 1.148), a higher concentration of fluoride (OR=1.001, 95%CI=1.000, 1.001) and/or a lower pH value (OR=0.002, 95%CI=0.000, 0.039). Discolouration of GIC was associated with concentration and frequency of APF gel application in extracted natural human teeth in vitro. Increasing discolouration rates were related to increased fluoride concentration and increasing acidity of APF gel. Further investigation is indicated.

Effect of fluoride content on ion release from cast and selective laser melting-processed Co-Cr-Mo alloys

Selective laser melting (SLM) alloy is gaining popularity in prosthetic dentistry. However, its biocompatibility has been of some concern because of long-term exposure to fluoride in the oral environment. The purpose of this study was to examine the effect of fluoride concentration on ion release from Co-Cr-Mo alloyspecimens fabricated using either SLM or lost-wax casting when immersed in an artificial saliva solution containing fluoride. Specimens were prepared with either a SLM system for the SLM alloy or conventional lost-wax techniques for the cast alloy. The specimen surfaces were wet ground with silicon carbide paper (400, 800, and 1200 grit) and immersed in modified artificial saliva solutions, the pH of which had been adjusted to 5.0 with lactic acid and which contained NaF at concentrations of 0.00%, 0.05%, 0.1%, or 0.2%. The metal ion content of the solution was determined with an inductively coupled plasma mass spectrometer. The results were submitted to 2-way ANOVA and regression analysis (α=.05). Fluoride concentration significantly influenced the elemental ion release from both the SLM and cast alloys. Thequantity of ions released increased significantly with increasing fluoride concentration. The ion release from the cast specimens was significantly greater than that from the SLM specimens. The performance of the SLM alloy in immersion tests demonstrates that this new technique is a superior choice because of its good biocompatibility.

Corrosion of laser-welded NiTi shape memory alloy and stainless steel composite wires with a copper interlayer upon exposure to fluoride and mechanical stress

In this study, laser-welded composite arch wire (CAW) with a copper interlayer was exposed to artificial saliva containing different concentrations of fluoride and to varying mechanical loads, and the resultant corrosion behavior was studied. The purpose was to determine the mechanisms by which fluoride and mechanical loads contribute to corrosion. Both exposure to fluoride and mechanical stress significantly decreased the corrosion resistance of CAW. Increasing concentrations of fluoride and loading stress caused increases of copper released and weight lost from CAW. Although the corrosion resistance of CAW declined with increasing fluoride concentration, it still meets the stability requirements for clinical use.

Fluoride Uptake and Net Primary Productivity of Selected Crops

Crop field soil collected from Sambalpur University campus of Odisha and treated with various fluoride concentrations was used to raise selected local crops. Background concentration of total and leachable fluoride content in soil was 95.19 and 8.89 ppm respectively. At the time of harvest of the crops, the total fluoride content was found to decrease and leachable fluoride content was found to increase both in control and experimental sets. This might be due to the addition of fluoride to soil in the experimental set up as well as availability of background fluoride content in soil and the irrigated water (i.e. 0.5 ppm). The fluoride accumulation in plant tissue increased with increase in the fluoride content in soil. Net Primary Productivity (NPP) of fluoride treated plants decreased in Brinjal by 6.64% - 56.72%, Tomato by 14.46% - 62.24% and Mung by 10.27% - 53.61%, all in 20 - 100 ppm fluoride range. However, NPP of Mustard, Ladies finger and Chili decreased by 15.58% - 61.21%, 12.28% - 52.78% and 40.8% - 90.65% in 10 - 50 ppm fluoride treated sets respectively in 10 - 50 ppm fluoride range. Maize NPP decreased by 12.17% - 61.20% in 20 - 100 ppm fluoride range as Rice NPP decreased by 6.64% - 56.72% in 20 - 100 ppm fluoride range. Pod formation was inhibited at 100 ppm fluoride amended soil in case of Mung, and 50 ppm in Ladies finger, 40 - 100 ppm in Maize and 30 - 50 ppm fluoride amended soil in case of Chilli. Thus, Maize and Chilli are more sensitive to fluoride contamination than other crops. In all the crops NPP decreased with increase in fluoride content in soil with significant decrease in highest concentration of fluoride.

Efficacy of silver diamine fluoride as a topical fluoride agent compared to fluoride varnish and acidulated phosphate fluoride gel: An in vivo study

Silver diamine fluoride (SDF) is already proven as an antibacterial agent in vitro. The present study was formulated to compare the efficacy of SDF as a topical fluoride agent in vivo with Fluoride Varnish and Acidulated phosphate fluoride (APF) Gel. A total of 123 children comprised of 82 boys and 41 girls were included in the study for a period of 18 months. Children were divided into three different groups - Group 1: SDF; Group 2: Fluoride Varnish; Group 3: APF Gel. All Subjects were evaluated through decayed, missing, and filled surface (dmfs) + DMFS index at 6th, 12th and 18th months as well as fluoride content in enamel at 6th month of follow-up. Significant increase in fluoride content of enamel was found in Group 1 when compared with Group 2 and 3, whereas no significant difference was found between Group 2 and 3. Reduction in dental caries found in all groups but inter group comparison shows no significant difference. In vivo application of SDF on enamel significantly increases fluoride content in enamel as compared to Fluoride Varnish and APF Gel and can be used effectively as topical fluoride agent.

Dental Fluorosis and Dental Caries Prevalence among 12 and 15-Year-Old School Children in Nalgonda District, Andhra Pradesh, India.

Background:Fluoride is a double edged sword. The assessment of dental caries and fluorosis in endemic fluoride areas will facilitate in assessing the relation between fluoride concentrations in water with dental caries, dental fluorosis simultaneously.Aim:The objective of the following study is to assess the dental caries and dental fluorosis prevalence among 12 and 15-year-old school children in Nalgonda district, Andhra Pradesh, India.Subjects and Methods:This was a cross-sectional study. Two stage cluster sampling technique was employed to select 20 schools from Nalgonda district. The oral examination of available 12 and 15-year-old children fulfilling the inclusion and exclusion criteria was carried out to assess dental caries and fluorosis. The examination was conducted by a single trained and calibrated examiner using the mouth mirror and community periodontal index probe under natural daylight. These areas were divided into four categories, low, medium, high and very high fluoride areas based on the fluoride concentration at the time of statistical analysis. The data was analyzed using Statistical Package for the Social Sciences version 16 (IBM, Chicago, USA).Results:The caries prevalence was less among 12-year-old children (39.9% [369/924]) compared with 15-years-old children (46.7% [444/951]). The prevalence was more among females (50.4% [492/977]) than males (35.8% [321/898]). The prevalence was more in low fluoride area (60.5% [300/496]) followed by very high fluoride area (54.8% [201/367]), high fluoride area (32.4% [293/904]) and medium fluoride area (17.6% [19/108]) in the descending order. The fluorosis prevalence increased with increasing fluoride concentration with no difference in gender and age distribution.Conclusion:Low fluoride areas require fluoridation or alternate sources of fluoride, whereas high fluoride areas require defluoridation. Defluoridation of water is an immediate requirement in areas with fluoride concentration of 4 parts per million and above as dental fluorosis is a public health problem in these areas with 100% prevalence.

In vitro fluoride induced genotoxic effect on human blood lymphocyte cells and its amelioration by emblica officinalis extract

Fluoride exhibited a significant increase in SCEs per metaphase plate (p<0.001) and SCEs per chromosome (p<0.05). Similarly, cell cycle proliferative index significantly decrease (p<0.001) in a dose-dependent manner in the three fluoride dose groups. Genotoxic indices such as nuclear deformities and frequency of micronucleus significantly (p<0.001) elevated with increased fluoride concentration. Furthermore, nuclear division index (NDI) and cell viability also noticed to be declined in fluoride treated cultures. Cultures with high dose of fluoride co-supplement with amla extract indicated a remarkable recovery in these genotoxic indices as comparable to control cultures. Antioxidant analysis of amla extract showed high free radical scavenging activity with EC50 value of 55.44 ± 0.12µg/ml. Conclusion Amla has a strong antioxidant system to scavenge the free radicals generated through toxic effect. Amla showed an antigenotoxic effect against fluoride and thus has a great potential for the application in medicinal products.

Effects of fluoride concentration on enamel demineralization kinetics in vitro

ObjectivesThe aim of the present study was to measure the effects of fluoride concentration on the real-time in vitro demineralization of enamel during exposure to caries-simulating conditions using Scanning Microradiography (SMR). MethodsEnamel blocks obtained from non-carious human molars were fixed in SMR environmental cells, through which acidic solutions (0.1M acetic acid, pH 4.0) were circulated for periods of 48h. SMR was used to quantitatively measure continuous mineral mass loss. Subsequently, the effects of sequentially increasing fluoride concentration (0.1–4500mg/L [F−]) in the acidic solutions were measured on the rate of enamel demineralization. ResultsThe data shows a log-linear relationship between [F−] and reduction in demineralization up to 135mg/L [F−]. Above 135mg/L, no further significant decrease in demineralization occurred. ConclusionThe optimum range of local fluoride concentration for reducing enamel demineralization was in the range 0.1–135mg/L [F−] under the conditions studied. Clinical significanceRelatively low [F−] can exhibit near-optimum protection. Increasing the fluoride concentrations above 135mg/L may not necessarily give an increased cariostatic benefit. Improving the means of delivery of relatively low fluoride concentrations to the oral fluids through slow releasing mechanisms, such as the oral fluoride reservoirs, is the more appropriate way forward for sustaining long-term clinical efficacy.

Synthesis of fluorine substituted hydroxyapatite nanopowders and application of the central composite design for determination of its antimicrobial effects

Synthetic biomaterials based on fluorine substituted hydroxyapatite are potentially attractive for orthopedic and dental implant applications. The new synthesis of fluorine substituted hydroxyapatite samples were done by neutralization, which consists of adding the solution of HF and H3PO4 in suspension of Ca(OH)2. Characterization studies from XRD, SEM and FTIR spectra showed that crystals are obtained with apatite structure and those particles of all samples are nano size, with an average length of 80nm and about 15–25nm in diameter. The central composite design was used in order to determine the optimal conditions for the antimicrobial activity of the synthesized samples. In order to evaluate the influence of operating parameters on the percent of viable cell reduction of Streptococcus mutans, three independent variables were chosen: exposure time, pH of saline and floride concentration in apatite samples. The experimental and predicted antimicrobial activities were in close agreement. Antimicrobial activity of the samples increases with the increase of fluoride concentration and the decreased pH of saline. The maximum antimicrobial activity was achieved at the initial pH of 4.

Effect of Fluoride Concentration and Water Content on Morphology of Titania Nanotubes in Ethylene Glycol Solution

Titanium dioxide (TiO2) nanotube arrays were prepared at room temperature by electrochemical anodization of a pure titanium foil in electrolyte solutions containing ethylene glycol as a solvent and de-ionized water and ammonium fluoride as additives. Since the morphology and size of TiO2 nanotubes play critical roles in determining their performance, the control of geometrical parameters of the nanotube arrays including length and inner diameter are of great importance. The present research demonstrates the significant effects of fluoride concentration and water content in anodizing electrolyte on formation of nanotubes and their dimensions. Scanning electron microscope investigation shows that nanotube arrays are no longer formed in very low or very high concentration of ammonium fluoride. Also, increase in fluoride concentration causes increase in lengths and inner diameters of the nanotubes. Moreover, it is evident that the maximum nanotube growth rate was achieved in medium amount of water. In addition, it is found that the nanotube inner diameter increases by adding more water to the solution.

Fluoride contamination mapping of groundwater in Northern India integrated with geochemical indicators and GIS

There are many incidents of increasing fluoride concentrations observed in India's groundwater. In the present study, the fluoride content was chemically analysed and integrated with geochemical model WATEQ4F sampled from Allahabad district, Northern India, with other water quality parameters. Geospatial technique was employed to depict the spatial distribution of fluoride concentrations, over this plain, normalized with WHO (World Health Organization) and BIS (Bureau of Indian Standards) standards represented in the form of spatially interpolated maps. Hydro-geological conditions, such as weathering, geochemical reactions, alkaline nature of water, ion-exchange and high variability in temperature range, were taken into account in describing the geo or anthropogenic contributions to fluoride in groundwater. A large database of available ancillary information on related factors, such as soil properties, geological settings and climatic and topographical information, on a local scale, were also taken into account to rationalize the results. The analysis implies that post-monsoon samples have elevated concentration of fluoride compared with the pre-monsoon samples, with several zones found severely contaminated with fluoride as compared with the set standards in both seasons. The correlation analysis revealed a high correlation of fluoride, with fluorite mineral saturation index, followed by calcite and magnesite, indicating that these minerals could be used as geochemical indicators for fluoride contaminated areas.

Novel curcumin–based method of fluoride determination – the PAGIKAND method

Fluoride concentrations above and below certain limits are deleterious to human health, having been implicated in diseases such as fluorosis, arthritis, caries, cancers etc. Better methods of its qualitative and quantitative determination are therefore necessary. A novel, less toxic and more environmentally friendly analytical method for determination of fluorides, named the PAGIKAND method, is proposed, based on the complex formation capability of diferuloylmethane with zirconium. Absorbance of the complex at its absorption maximum of 465 nm was found to decrease (up to 94.69%) with increase in fluoride concentration in solution (up to 10 mg F- L-1). The optimum pH for the required complex formation was determined to be 8.5, and the Detection Limit (LOD) for the proposed method was calculated to be 1.3 x 10-6 mol L-1. The proposed method was applied to the analysis of fluorides in river water and T .test was used to compare contents of fluorides determined using a known method (SPADNS) with those determined using the new method. The mean fluoride concentration for the new method was found to be 0.1232}0.030 mg L-1 while that of the SPADNS method was 0.1257}0.289 mg L-1. At 95% confidence interval (p = 0.05) and 18 degrees of freedom, with critical value of 2.10, the „ texp„ was 1.987. This indicates there is no significant difference between the results obtained from the known method (SPADNS) and that obtained from the proposed method, since „ texp„ &lt; tcritical.KEYWORDS: Novel Method, Fluoride, Spectrometry, Curcumin, Diferuloylmethane