Determination Of Boron Research Articles

HYDROXY ACIDS AND POLYOLS AS POTENTIAL EXTRACTANTS FOR IONMETRIC DETERMINATION OF BORON IN SOILS

Boron is an essential element for plants, animals, and humans. Its deficiency in plants may result in reduced growth rates, yield loss, and even death. At the same time, excess of boron is toxic for both plants and living organisms. Boron is important for steroid hormones production, vitamin D and minerals metabolism, formation of bone tissue, and affects estrogen and testosterone levels. The primary source of boron for humans and other living organisms is plant-origin food. The richest ones are fruits and nuts. High concentrations of boron are found in raisins (22 mg/kg), peanuts (17 mg/kg), peanut butter (14,5 mg/kg). In the agriculture the boron monitoring in soils and water irrigation is particularly important because this element is crucial for plant growth Boron deficiency has a drastic effect on fruit quality and yield, even when there are only mild or moderate foliar symptoms.
 The main source of boron for plants is soil and water. Quantitative determination of boron in soil extracts can be performed using spectrophotometric, potentiometric, chromatographic, atomic absorption spectrophotometric, and inductively coupled plasma techniques. The most popular are inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). These methods are described in the appropriate standards PN-EN ISO 11885:2009 and PN-EN ISO 17294–1:2007.
 Boric acid is known to form complexes through esterification reactions with hydroxy-group in molecules of amino- and carboxylic acids, carbohydrates, nucleotides and vitamins that can be used for boron extraction from soils. Partial esterification results in monoesters (1:1 complex) and complete esterification leads to the bicyclic diester (1:2 complex).
 In present research the tetrafluoroborate selective sensor applicable for fluoroborate formation reaction monitoring was used as an analytical tool for the investigation of an impact of soil extraction procedure for boron analysis. The investigation of alternative soil boron extraction procedures using α-hydroxy acids (and other cis-diol containing compounds) and subsequent quantitative analysis of boron by kinetic-potentiometric monitoring of fluoroborate formation rate with use of previously developed [BF4]¯-selective electrode have been performed. The kinetics of complex destruction under fluoride containing acidified media by means of kinetic-potentiometric analysis has been investigated. The possible boron losses during its extraction from soils have been checked.

Boron Determination in Basrah Rivers Using Solid State Nuclear Track Detector

Consumers who ingest boron-contaminated food and water face a variety of health concerns. As a result, the food boron content must be determined. For this research, drinking water samples were collected from different areas in southern Basrah, Iraq. The collected water samples were examined using the SSNTDs method to determine boron levels. Boron values in the Al Khatwa district ranged from 0.21 ppm to 9.8 ppm in Al Shuaiba farm2. The results of this investigation were compared to worldwide standards and prior studies. The Iraqi government may use these data to establish guidelines for reducing radioactive pollution of Basrah's drinking water. The boron levels in the 43 surface water samples evaluated in this study were lower than the international standard limits. However, there are some regions where the rates are quite high. As a result, in most areas, the boron level in Basrah's drinking water is normal. However, there is a possibility that boron pollution will become a major issue soon. As a result, further research will be needed in the future.

Development of a Flow-injection Analytical System for Boron Determination by Chromotropic Acid with a Simple Flow System and a Compact Fluorometric Detector Using Ultraviolet LED as an Excitation Source

Development of a Flow-injection Analytical System for Boron Determination by Chromotropic Acid with a Simple Flow System and a Compact Fluorometric Detector Using Ultraviolet LED as an Excitation Source

Evaluation of Different Extractants for Boron Estimation in Soils of Odisha and Andhra Pradesh

The present study was conducted to compare the four different extractants widely used in boron (B) determination in soils and to screen the most suitable extractant for acidic (Alfisols) and alkaline (Vertisols) soils of Odisha and Andhra Pradesh. A total of 200 surface soil samples were collected across two sites (100 from each site) representing different pH ranges. Hot-water-soluble boron (HWS-B) extraction procedure being the most widely used B determination procedure was kept as a benchmark in order to compare the B extracting efficiency by the extractants viz., 0.01 M Calcium Chloride (CaCl2), 1 N Ammonium acetate (NH4OAc) pH-7.0 and 0.01 M Barium Chloride. The mean values of hot water extractable B for acidic soils were 0.49 (mean between 0.18 and 1.50 mg kg-1), CaCl2 – 0.42 (mean between 0.14 and 1.52 mg kg-1), BaCl2 – 0.45 (mean between 0.10 and 1.68 mg kg-1) and NH4OAc – 0.60 (mean between 0.17 and 2.43 mg kg-1). The mean values of hot water extractable B for alkaline soils were 1.87 (mean between 0.71 and 4.79 mg kg-1), CaCl2 – 1.57 (mean between 0.45 and 5.43 mg kg-1), BaCl2 – 1.37 (mean between 0.52 and 4.15 mg kg-1) and NH4OAc – 1.92 (mean between 0.85 and 8.33 mg kg-1) in acidic and alkaline soils respectively. The coefficient of variation for extractable B varied from 53.0 to 66.6 and 42.7 to 55.7 in acidic and alkaline soils respectively. The variation in B extracting efficiency in both the types of soils was found in the order: Hot water > Hot CaCl2 > BaCl2 > NH4OAc. Authors conclude that amongst all the compared extractants, 0.01 M CaCl2 extraction may be an adequate procedure for B determination in both the acidic as well as alkaline soils.

Colorimetric and fluorometric determination of boron using β-diketone–BF2 compounds containing catechol moiety

In this study, we attempted to develop a new boron quantification reagent using β-diketones, because β-diketones often exhibit strong absorption and luminescence and react with boric acid. The luminescence intensity remarkably varied with the addition of boric acid to a solution of β-diketone containing 4-methoxyphenyl groups. However, luminescence intensity gradually decreased with time because of the tautomerization of the enol form of β-diketone to its keto form. Therefore, in this study, we synthesized novel β-diketone–BF2 compounds in which the β-diketone site was cross-linked with BF2 to avoid changes in the luminescence intensity owing to the keto-enol tautomerization. We introduced a catechol moiety as a reaction site with boron and examined their effectiveness in quantifying boron using absorption and emission spectroscopy. Furthermore, the synthesized β-diketone–BF2 compounds (1–9) that contained 4-dimethylaminophenyl (4-NMe2Ph) or 4-methoxyphenyl (4-MeOPh) group and catechol or salicylic acid moiety as the reaction site, were characterized using various analytical methods. No correlation was observed between the pKa values of β-diketone–BF2 compounds and the formation constants for the reactions with boric acid (log K1). Additionally, quantification limit estimation carried out using absorption and emission spectroscopy suggested that β-diketone–BF2 compounds 3 and 7, which contain 4-NMe2Ph group and catechol moiety, can be used to determine boric acid concentrations > ca. 2 × 10–4 M. This study demonstrated the usefulness of the β-diketone-BF2 compound as a colorimetric and fluorescence quantifying reagent for boric acid.

Fusion method for sample preparation for isotopic composition determination of boron in refractory materials by thermal ionization mass spectrometry with validation using dissolved and purified samples

Various refractory samples of boron such as titanium borides, rare earth borides, boron carbides having natural and non-natural isotopic composition were analysed by thermal ionization mass spectrometry as Na2BO2+ ions. Samples were fused with Na2CO3 directly on the filament after adjusting the B/Na mole ratio to 2 and in certain cases modifications in the loading technique were required to obtain precise 10B/11B isotopic ratio. A few of the samples expected to have natural 10B/11B ratio were observed to be slightly enriched in 10B. Dissolved samples as well as boron purified by extraction with 5% 2-Ethyl Hexane Diol(EHD) were analysed for 10B/11B ratio to ascertain the accuracy of the results obtained by the direct fusion method. Precision of about 0.02% (1RSD) was obtained for 10B/11B isotopic ratio measured in all the three types of samples. A good agreement of the dissolved sample and purified boron fraction with the directly fused sample validated the direct fusion method as a fast and reliable technique for isotopic analysis of boron in refractory samples.

Electrochemical determination of boron using the signal suppression of mannitol on a gold nanoparticle coated p-Aminothiophenol polymer electrode

In this study, a glassy carbon electrode (GCE) modified with gold nanoparticles (AuNPs) and coated with electropolymerized p-aminothiophenol (p-ATP) was used as a modified electrode (GC/AuNPs/PATP electrode) for the indirect electrochemical determination of boron (B) using boric acid-mannitol complexation. The developed electrode showed good electroactivity for B determination. Firstly the current intensity of mannitol was measured, then B (as H3BO3) was added to the medium and the unreacted mannitol was measured. The decrement in current intensity was recorded against B concentration to build linear calibration curves within the range of 5–50 mg L−1 of B using square wave voltammetry (SWV), and the oxidation peak potential of mannitol was observed at 0.97 V. The limit of detection (LOD) and limit of quantification (LOQ) were 1.43 mg L−1 and 4.77 mg L−1, respectively. Boron (5 mg L−1) was determined with quantitative recovery in the presence of 100-fold concentration (except 5-fold for Fe3+) levels of the potentially interferent ions (Cl−, SO42−, HCO3−, CO32−, NO32−, PO43−, NH4+, Cu2+, Mg2+, Ca2+, Na+, K+, Fe3+) in water using the proposed SWV method. Fe3+ and Cu2+ interferences could be overcome with cation exchange resin removal. Additionally, boron was determined in synthetic and real seawater samples. The proposed SWV method was statistically validated against the spectrophotometric carmine method using seawater, antibacterial hand sanitizer gel and boron/potassium nitrate (BPN) pyrotechnic formulation.

Analysis of influencing factors on the method for determining boron concentration and dose through dual prompt gamma detection

A method based on the cross-sectional relationship between 10B(n, α)7Li and 1H(n, γ)2H was proposed to detect and reconstruct the three-dimensional boron concentration/dose distribution in vivo during boron neutron capture therapy (BNCT). Factors such as the neutron energy, fluence rate, and degree of non-uniform distribution of the boron concentration in a voxel may affect the results of this method. A theoretical analysis of the accuracy of the method using a Monte Carlo simulation shows that the determining error is generally less than 1% under different tumor locations and neutron source configurations. When the voxel size is larger than 0.4 cm, the determining error might be higher for a non-uniformly distributed boron concentration in the voxel because of the changes in the neutron energy and fluence rate. In conclusion, the proposed method enables an accurate three-dimensional boron determination in vivo during BNCT.

Determination of boron in in-house graphite reference material by instrumental charged particle activation analysis

Due to high thermal neutron absorption cross-section, boron (B) content is a binding specification for nuclear grade graphite. Reliable analytical methods are essential to determine boron at trace to ultra-trace levels. Analytical Chemistry Division, Bhabha Atomic Research Centre, India has prepared an in-house graphite reference material (GRM). A Charged particle activation analysis methodology has been developed for quantification of B in graphite matrix. Detection limit for boron using this methodology is 1.4 mg kg−1. This in-house GRM can be used for quantification of B in unknown graphite samples, validating existing analytical methods and for the development of new analytical methods.

Using Chemically Active Additives for the Arc Atomic Emission Determination of Boron in Graphite

We studied the effect of chemically reactive additives of AlF3, ZnF2, and SrF2 on the character of boron evaporation from a crater in a DC arc electrode in the analysis of graphite. The introduction of fluorinating additives contributes to a rapid, complete, and stable evaporation of boron. Zinc fluoride is the most effective among the studied compounds. The use of this additive made it possible to lower the limits of quantification of boron in graphite to 5 × 10–6 wt % and to double the reproducibility of the results. The use of zinc fluoride also eliminated the systematic error due to the difference in the evaporation patterns of boron oxide and carbide, which improved the reliability of the determination results.

SPECTROPHOTOMETRIC DETERMINATION OF BORON IN FOOD PRODUCTS BY ESTER BORATE DISTILLATION INTO CURCUMIN

Spectrophotometric determination of boron in food products by ester borate distillation into curcumin was studied. The sensitivity and selectivity of curcumin method were overcome by generating ester borate at proper temperature, time and pH. Boron was separated as triethyl borate by distillation in a vessel using ethanol solvent and reacted with curcumin. Distillation system reached optimum condition at temperature of 75oC and pH 5-6. Boron-curcumin complex was measured at 555 nm after 10 minutes of reaction. Separation of boron by distillation method complied with validation parameters. The standard curve was linier at concentration range of 1.2-4.8 ppm (R2=0.9995) and had molar extinction value (?) 4.7 x 105 L mol-1 cm-1 for high sensitivity level which is higher than the previous study. Percent recovery was found to be 96.09-104.92 %. Boron content in meatball and tofu products was in the range of 1.406-3.589 and 0.010-1.085 mg/kg. Ester borate distillation into curcumin has been successfully applied to the determination of boron in food products because of its high selectivity and sensitivity.

Determination of boron in aqueous solution using a method combining laser ablation molecular isotopic spectrometry with molecular laser-induced fluorescence and isotopic dilution

Laser-induced breakdown spectroscopy (LIBS) has been applied in quantitative and isotopic detection of boron.

Boron determinations of silicate reference rocks by the isotope dilution method in a high-background environment

Boron determinations of silicate reference rocks by the isotope dilution method in a high-background environment

A novel conductometric titration approach for rapid determination of boron

In laboratories dealing with radioactive samples it is important to minimize both the sample size and also the associated waste generated in an analysis. To meet this objective a rapid conductometric titration technique is developed to determine boron in the moderators of Pressurized Heavy Water Reactors (PHWR’s). Using this novel PC interfaced titration facility a minimum tenfold reduction in sample size is achieved compared to conventional conductometric titration. Determination of boron is based on the conversion of extremely weak boric acid to better conducting boron mannitol complex and titrating the complex against NaOH. Various parameters affecting the analysis, when moving from large to small sample size, are analyzed and optimized. The technique is primarily proposed for the assay of boron (≥0.5 ppm) during reactor startup. Each analysis requires less than 10 minutes. The precision obtained at a boron level of 0.5ppm is 4.6 % RSD. The technique is a good alternative to less sensitive carminic acid based spectrophotometric method.

Features of the use of spectral methods for the determination of boron in natural waters

Features of the use of spectral methods for the determination of boron in natural waters

Application of a lab-made ternary Fe-Cr-Al coil vaporizer coupled to ICP OES for boron determination in powdered food after the sample preparation in alkaline media

This work presents the development of a method for boron determination in food using a lab-made ternary Fe-Cr-Al coil vaporizer (composed of a glass chamber, a Fe-Cr-Al coil, and a power supply) after the sample dissolution in tetramethylammonium hydroxide. The sample preparation and the instrumental parameters were optimized using a central composite design. The chemical characterization and surface analysis of the Fe-Cr-Al coil were performed. The temperature of pyrolysis and vaporization, as well as the memory effect, and accuracy and analytical figures of merit were studied. After the proper optimization, the ternary Fe-Cr-Al coil applied as a vaporization system presented to solve the memory effect for boron determination in ICP OES. The comparison with a conventional sample introduction system presented good accuracy, as well as the analytical curve, showed good sensitivity with a good R-squared (0.992). The limit of detection obtained was 2 µg g−1.

Determination of boron by inductively coupled plasma atomic emission spectroscopy. Biodistribution of 10B in tumor-bearing mice

The determination of boron in animal organ tissues using inductively coupled plasma atomic emission spectroscopy (ICP AES) has been optimized for analytical support of boron neutron capture therapy of cancerous tumors. The proposed technique is universal and rapid. The methodology includes: preliminary acid decomposition at elevated temperatures and pressure (if necessary), determination of boron by ICP AES in the obtained solutions using reference samples based on single-element solutions. The method is verified by spike experiment and varying the weight-samples. The ICP AES technique was used to evaluate the accumulation of boronophenylalanine and borocaptate in mice organs. Biodistribution of 10B in the case of intravenous administration of the drug to SCID mice with SPF status using the human glioblastoma cell line U87 was investigated.

Molecular structure, vibrational spectra and density functional theory of the spiro-conjugated anticancer active molecule rubrocurcumin

Rubrocurcumin, well-known for its application in photometric determination of boron in various matrices, has attracted substantial attention due to its applications in biological and pharmacological fields. Here, geometrical optimization, diverse bonding features and potential energy surface scans were studied by use of density functional theory. Vibrational analysis of rubrocurcumin was done by Fourier transform infrared and Fourier transform Raman spectroscopies. The electronic density distribution of atoms in the molecule was analyzed by use of natural bond orbital analysis. Conceptual density functional theory-based local reactivity descriptors were used to understand the relationship between structure, stability, and chemical reactivity.

Cost-effective voltammetric determination of boron in dried fruits and nuts using modified electrodes

Cost effective, simple and accurate two voltammetric methods for determination of boron in hazelnut, peanut, almond, raisin, prune and date samples were described. Metal nanoparticles-carbon nanotube modified glassy carbon electrode (MNP/CNT/GCE, M = Au or Cu) and poly xylenol orange modified pencil graphite electrode (p-XO/PGE) were used as working electrodes. The oxidation of alizarin red s (ARS) in the boron-ARS complex at MNP/CNT/GCE and the oxidation of tiron in the B-tiron complex at p-XO/PGE were monitored as response. The limit of determination values (based on visual evaluation) for CuNP/CNT/GCE, AuNP/CNT/GCE and p-XO/PGE were calculated as 100 µg/L, 125 µg/L and 80 µg/L, respectively. The results were compared with the results obtained by inductively coupled plasma mass spectrometric method and no significant difference between the results was observed. The accuracy experiments of the methods and uncertainty calculations were also performed using a certified reference material (UME CRM 1202 Elements in Hazelnut).

A paper-based colorimetric assay with non-instrumental detection for determination of boron in water samples

The present work reports on the combination of paper-based analytical devices (PADs) and information technology (IT) equipment for non-instrumental determination of boron. PADs prepared with curcumin as a receptor and ethanolic extracts of Curcuma longa L. powder were evaluated for sensing. The colorimetric assay is based on a two step-strategy involving initially the formation of rosocyanin in the PAD under acidic conditions, with subsequent color change (from red to blue-green) at alkaline pH. The color change produced in the PAD is then exploited for determination of boron by digitization and image processing with IT devices (scanner and tablet camera) and an image analysis program, respectively. Under optimal conditions, the proposed assay showed limits of detection in the range 0.2–0.8 mg/L depending on the PADs and IT devices used for colorimetric reaction and digitization, respectively. In addition, the repeatability, expressed as relative standard deviation, was found to be below 5% (5 mg/L, N = 10). PADs prepared with curcumin and ethanolic extracts of Curcuma longa L. powder showed excellent lifetime and successful applicability to the analysis of water samples of different complexity with recoveries in the range 93–105%.