Aluminum Monofluoride Research Articles

Determination of fluoride in bone by aluminum monofluoride molecular absorption spectrometry

Phosphate, by virtue of its intrinsic capacity to form complexes with aluminum, interferes extensively with the aluminum monofluoride molecular absorption spectrometric (MAS) method for fluoride. However, it has now been found that in the presence of calcium there was no such interference when the ratio of phosphate to calcium was similar to that in calcium phosphate. On the other hand, there was an enhancement of the AlF signal. This observation is now the basis of an AlF MAS method for determination of fluoride in bone ash, which is essentially calcium phosphate. The procedure involves injecting formic acid solutions of bone ash and of calcium phosphate-fluoride standards into a graphic furnace and obtaining the AlF absorbances at 227.5 nm. Results of analyses of bone samples obtained by the AlF MAS method are in excellent agreement with those obtained with the fluoride electrode.

The infrared emission spectrum of gaseous AIF

The high-resolution infrared emission spectrum of aluminum monofluoride has been observed with a Fourier transform infrared spectrometer. More than 500 rovibrational lines from bands with v = 1 → 0 to v = 5 → 4 were assigned. The infrared data have been combined with previous microwave and millimeter-wave transition frequencies from the literature to yield improved Dunham coefficients for the X 1Σ + electronic ground state of AIF.

The reactions of silicon monoxide and aluminium monofluoride with 2,2′-bipyridyl

The high temperature species, SiO and AlF, have each been treated with 2,2′-bipyridyl in tetrahydrofuran solution at − 105 °C and in an adamatane matrix at − 196 °C to give products which have spectroscopic properties closely resembling the known compound [SiCl 2(bipy) 2]. When initially formed the products are highly coloured and paramagnetic in solution or in the adamantane matrix and their EPR spectra show the presence of singlet and triplet species. In the triplet species, two electrons are transferred from the silicon or aluminium centre to two bipyridyl ligands which must lie orthogonal to each other across the metal centres but it is uncertain whether the species are monomeric or oligomeric. Evaporation of the solutions causes irreversible precipitation of pyrophoric solids of composition SiO(bipy) or AlF(bipy).

New Rydberg states of aluminum monofluoride observed by resonance-enhanced multiphoton ionization spectroscopy

proposad here, a thermal excitation or activation energy of 2500 cm-' is required for indole to populate vibrational levels in the 'Lb state which couple effectively with the 'La state to produce a vibronic state that is subject to efftcient nonradiative decay. In the case of 3-methylindole, it is possible that the methyl substituent provides lower energy vibrational modes in the 'Lb state which lead to nonradiative decay.

Determination of fluoride in sea-water by molecular absorption spectrometry of aluminium monofluoride after removal cation and anion interferences

Three procedures are proposed for the determination of trace levels of fluoride in sea-water, based on the formation of aluminium monofluoride in an electrothermal graphite furnace, followed by measurement of its molecular absorption at 227.45 nm. They involve the use of dilution, a matrix modifier, or a matrix modifier and an ion-exchange resin, and are all acceptably sensitive and specific for fluoride. Interferences from cations and anions are removed by a simple 20-fold dilution of the sample. At 10-fold sample dilution, chloride interference can be removed by adding 0.3 M ammonium nitrate together with 0.01 M aluminium + 0.01 M strontium as a matrix modifier. The same matrix modifier is valid for use with 5-fold sample dilution and a cation-exchange step to avoid matrix affects from cations and chloride. The detection limit is about 8–10 ng/ml fluoride and the determination limit is 20 ng/ml. The precision of peak-height measurement at 0.2 μg/ml is 5–7%.

Evaluation of Analytical Methods for Fluorine in Biological and Related Materials

During the past two decades, some major pitfalls in fluorine analysis have been recognized and overcome. Therefore, it is important that facts be separated from fallacies in published literature on levels and forms of fluorine (ionic, bound, covalent, etc.) in biological materials, in order that correct perceptions of physiological, biochemical, and toxicological aspects of inorganic as well as organic fluorine compounds can be formed. Trace amounts of inorganic fluoride in biological samples can now be accurately determined with the fluoride electrode either directly or following diffusion, adsorption, or reverse extraction of fluoride (when necessary). The aluminum monofluoride molecular absorption technique provides an excellent rapid method for determination of trace amounts of inorganic fluoride (in the absence of organic fluorine). Fluorine in most organic fluorine compounds is not available for distillation, diffusion, or reverse-extraction. The sample needs to be ashed (open ashing) or combusted (oxygen flask, oxygen bomb, pyrohydrolysis) for covalently bound fluorine to be converted to fluoride ions. This can now be readily accomplished at room temperature by the reductive cleavage of the C-F bond with the sodium biphenyl reagent. Some recommendations for future research have been made.

Evaluation of biological sample mineralisation methods for the determination of fluorine by graphite furnace molecular absorption spectrometry

Various mineralisation methods were evaluated as means of treating different liquid and solid biological samples for the determination of fluorine by the formation of aluminium monofluoride in an electrothermal graphite furnace and molecular absorption spectrometry (AIF-MAS). Simple sample dilution and the use of 0.01 M Al3+ + 0.01 M Sr2+ solution as a matrix modifier are sufficient to determine the fluorine content in most liquid samples, although some require the addition of 0.3 M ammonium nitrate to the matrix modifier solution in order to diminish background absorbance. In solid samples, treatment methods routinely used with fluoride ion-selective electrodes such as microdiffusion, furnace ashing - microdiffusion and oxygen flask combustion, were tested for compatibility with AIF-MAS. The results were compared with those obtained with a fluoride ion-selective electrode. The proposed mineralisation methods were checked for applicability to different plants, foodstuffs and other biological materials. Some of the methods gave an over-all precision of better than 10%, which is often acceptable, and all methods gave recoveries above 80%. Differences between labile + ionic fluoride and total fluorine can be established by sample treatment.

Structure of silicon monoxide dimer: a comparison between aluminum monofluoride dimer, silicon monoxide dimer, and phosphorus mononitride dimer. Matrix infrared investigation and ab initio calculation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of silicon monoxide dimer: a comparison between aluminum monofluoride dimer, silicon monoxide dimer, and phosphorus mononitride dimer. Matrix infrared investigation and ab initio calculationHansgeorg Schnoeckel, Thomas Mehner, Harald S. Plitt, and Stephan SchunckCite this: J. Am. Chem. Soc. 1989, 111, 13, 4578–4582Publication Date (Print):June 1, 1989Publication History Published online1 May 2002Published inissue 1 June 1989https://doi.org/10.1021/ja00195a008RIGHTS & PERMISSIONSArticle Views179Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (678 KB) Get e-Alerts Get e-Alerts

Determination of fluoride in drinking water and sea water by aluminium monofluoride molecular absorption spectrometry using an electrothermal graphite furnace.

A method is presented for the determination of trace levels of fluoride in drinking water and sea water, based on the formation of aluminium monofluoride in an electrothermal graphite furnace, followed by molecular absorption at 227.45 nm. Two linear intervals extending over wide F– concentration ranges (0–0.2 and 0.2–0.4 µg ml–1 for the peak-height relationship and 0–1 and 1–2 µg ml–1 for the peak-area relationship) were found.The proposed method was applied to natural and artificial drinking and sea waters from a variety of sources and with different saline contents. The detection limit was 8 ng ml–1 and the determination limit 20 ng ml–1. The peak-height precision at 0.2 and 0.4 µg ml–1 of F– was 5% and 7%, respectively.F– contents can be measured with a simple dilution. The use of a deuterium lamp allows simultaneous background correction. Interferences from cations, acidic media and anions were investigated.

Effect of matrix modifier and furnace material on the determination of traces of fluoride by electrothermal molecular absorption spectrometry of aluminum monofluoride

In the determination of fluoride by AlF absorbance measurements, the interference from strontium nitrate is avoided by using magnesium nitrate or barium nitrate added to aluminum solution as the matrix modifier. The effects of the graphite-furnace material on AlF absorbance are investigated. Glassy carbon and synthetic carbon gave longer furnace lifetimes and better sensitivity than the other materials tested. The maximum sensitivity (4.2 μg ml −1 fluoride for 0.0044 absorbance with a 10-μl injection) was obtained with synthetic carbon. The r.s.d, was <5% for 0.1 μg ml −1 fluoride ( n=10). Na +, K +, Pb 2+, Zn 2+, Cu 2+ and Ag + did not affect the measurements up to 500 μg ml −1, but Ni 2+, Co 2+, Fe 2+, Sr 2+ and especially Ca 2+ depressed the absorbance.

A study of aluminium monofluoride and aluminium trifluoride by high-temperature photoelectron spectroscopy

The Hel photoelectron spectrum of gaseous AIF(X 1Σ +) has been recorded and the first three cationic states have been assigned with the aid of PNO/CEPA calculations. The first band shows vibrational structure and analysis of the component separations and relative intensitives leads to values of ω c = 1040 ± 40 cm −1 and r c = 1.59 ± 0.01 Å in the AIF + (X 2Σ +) state; the corresponding theoretical values are 960 cm −1 and 1.60 Å respectively. The first adiabatic ionization potential, 9.73 ± 0.01 eV, allows a determination of the quantum defect, δ, in a number of previously observed Rydberg states of AIF. The Hel photoelectron spectrum of gaseous AIF 3 has also been obtained. It is assigned on the basis of ab initio molecular orbital calculations and comparison with the corresponding BF 3 spectrum.

Direct determination of trace fluorine in milk by aluminum monofluoride molecular absorption spectrometry utilizing an electrothermal graphite furnace

The determination of ultratrace levels of fluorine in bovine milk has been investigated by molecular absorption spectrometry using aluminum fluoride formed in an electrothermal graphite furnace. Aluminum (0.01 M, 20 μl, strontium solution (0.1 M, 10 μl) and milk sample (10 μl) were applied in the graphite furnace, and after drying and ashing, the furnace was heated at about 2700 K in 7s. Molecular absorption of aluminum monofluoride was measured at 227.45 nm, where simultaneous background correction was made with a deuterium lamp. The content of 0.033 μg F ml −1 was found for commercial bovine milk.

Determination of fluorine in urine and blood serum by aluminum monofluoride molecular absorption spectrometry and with a fluoride ion selective electrode.

Determination of fluorine in urine and blood serum by aluminum monofluoride molecular absorption spectrometry and with a fluoride ion selective electrode.

Platinum atomic lines for determination of ultratrace fluoride by aluminum monofluoride molecular absorption spectrometry

Platinum atomic lines for determination of ultratrace fluoride by aluminum monofluoride molecular absorption spectrometry

Subnanogram fluorine determination by aluminum monofluoride molecular absorption spectrometry

Subnanogram fluorine determination by aluminum monofluoride molecular absorption spectrometry

Observation of a 3II-X 1Σ intercombination emission in AIF

Emission from the a 3II state to the ground state X 1Σ + of aluminum monofluoride, AIF, has been observed from flames produced by reactions of Al with SF 6, NF 3, and F 2. The observed spectrum confirms the calculated value of Barrow et al. of the triplet-singlet separation. Pressure dependence of the emission has been studied and interpreted in terms of production and quenching processes.

Physical chemistry in halide metallurgy

which immediately shows (4) that the transfer of condensed aluminum into the vapour state via the aluminum monochloride is significantly less endothermic than the direct evaporation and can, therefore, be expected to occur at lower temperatures. (The data used (4) at that time in kcal were hI = -89.5, h3 = -71.2 and H(ev) = 74.6; for a quantitative evaluation see the thermodynamics of Reaction 3 below using more modern data.) At about the time the author came to these conclusions, Klemm and Voss (5) quite independently investigated experimentally the reaction between liquid aluminum and solid aluminum fluoride by the method which Zintl (6) had applied for the identification (and preparation) of volatile unstable lower oxides and attributed Willmore's discovery to the formation of a volatile aluminum monofluoride. However, the use of the vapour of aluminum cWoride instead of Willmore's solid fluorides would have the great advantage that the resulting monohalide vapour should, on cooling, disproportionate into solid or liquid aluminum and aluminum trichloride vapour which, because of its low sublimation temperature (182°C), must remain in the gas phase. The aluminum should therefore condense free from any admixture of the halide. The expectations about the transport of aluminum in aluminum chloride (and also bromide) vapour were confirmed in experiments (7) in which aluminum chloride vapour under reduced pressure was passed over aluminum and aluminum scrap (7.5 per cent metallic impurities) at temperatures of about 1250K. A condensate of pure aluminum, free from any cWoride, was obtained in far greater amounts than could have been expected by evaporation alone. At 1250K and at pressures below 1/100 atm the yield of distilled aluminum corresponded to nearly total (80 to 90 per cent) conversion of aluminum trichloride into monochloride; it fell to lower values at lower II AI(Q) = AI(g) + H(ev)

Millimeter and Submillimeter Wave Spectrum and Molecular Constants of Aluminum Monofluoride

Rotational transitions of 27Al19F have been measured in the millimeter and submillimeter wave regions to frequencies of 461 Gc/sec. Vibrational states up to υ = 4 were observed. From analysis of the data the following Dunham rotational constants were obtained: Y01 = 16 562.930 ± 0.006 Mc/sec, Y11 = − 149.420 ± 0.009 Mc/sec, Y21 = 0.515 ± 0.004 Mc/sec, Y31 = 1.4 ± 0.6 kc/sec, Y02 = − 31.37 ± 0.02 kc/sec, and Y12 = 0.046 ± 0.014 kc/sec. The Dunham potential constants found are: a0 = 2.9167 ± 0.0019 × 105, a1 = − 3.1850 ± 0.0009, a2 = 6.82 ± 0.06, and a3 = − 11.6 ± 0.6 cm−1. The nuclear quadrupole coupling constants obtained are: eqQ(27Al) = − 37.59 ± 0.25 Mc/sec for υ = 0 and eqQ(27Al) = − 37.14 ± 0.6 Mc/sec for the υ = 1 vibrational state. Vibrational constants derived are ωe = 802.85 ± 0.25 cm−1 and ωexe = 4.86 ± 0.06 cm−1. The equilibrium internuclear distance re = 1.65436 ± 0.00002 Å was obtained.

Reactions of aluminum monofluoride with covalent fluorides

Reactions of aluminum monofluoride with covalent fluorides

Study on Reaction between aluminium and aluminium trifluoride

The disproportionation reaction of aluminium and its halides is studied by means of a differential thermal analysis at reduced pressure, and the temperature ranging from 1, 250°K to 1, 330°K. The reaction proceed through the formation of aluminium monofluoride by the direct liquid aluminium and solid aluminium trifluoride reaction.The aluminium monofluoride pressure versurs temperature are determined by the following equation:2Al(l)+AlF3(s)=3AlF(g)logp(mmHg)=-11, 270/T+10.267.Thermodynamic consideration is also attempted with respect to the above reaction.