Determination Of Boron In Steel Research Articles

Optimization of Curcumin Method and Usage of Natural Curcumin in Determination of Boron in Steel

Boron containing alloy steels are mainly used in constructional, automotive and many other applications. The presence of even trace amounts of boron affects greatly on the properties of steel such as hardness and machinability. Therefore, it is important to determine it accurately and precisely in the manufacture of these alloys. Due to the drawbacks of common advanced techniques such as Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), the universally accepted method for determination of boron in steel is the spectrophotometric method using curcumin as an auxiliary agent.
 Although curcumin is the most sensitive spectrophotometric reagent for the above analysis, synthetic curcumin is relatively expensive and it tends to degrade rapidly once it is exposed to air. Furthermore this method is time consuming. Therefore, this study was carried out in order to improve and optimize the available spectroscopic method and to investigate the possibility of using natural curcumin extracted from turmeric in the above analysis.
 The results of the study implied that natural curcumin extracted and purified from turmeric can be used as accurately and precisely as synthetic curcumin in the analysis of boron in steel. A boron-steel alloy sample found to be containing 0.26±0.01 percent of boron with synthetic curcumin gave a concentration of 0.25±0.00 percent of boron with natural curcumin, indicating no significant difference in the determination. A steel sample found to be containing 0.27±0.01 percent of boron with filter paper ashing step gave a concentration of 0.26±0.01 percent of boron without filter paper ashing step indicating no significant difference. Altering the refluxing step of current procedure significantly changes the concentration of boron indicating that the refluxing step cannot be optimized further.

A simple and rapid method for determination of boron in fast breeder reactor components

The present paper describes a new analytical method developed for direct determination of boron in steels using radio frequency glow discharge optical emission spectrometer. “Single parameter alternative method” technique has been used to optimize the various experimental conditions of glow discharge plasma such as forward power, gas pressure inside plasma chamber, pre-integration time, and integration time. Different emission lines for boron were studied and inter element interference effect is also discussed in the paper. A complete statistical analysis has been done to validate the developed method. A RSD of less than ±5% is achieved for boron in the range of 0.0010–0.020% in Steels using this method.

Determination of Boron in Steel and Iron Using Standard Addition Method

Determination of Boron in Steel and Iron Using Standard Addition Method

질산-이플루오린화암모늄 분해 및 ICP-MS에 의한 철강 중 붕소 정량에 관한 연구

Various studies have been done to improve the properties of the steel by adding boron to the steel. Some studies have reported on the analysis of the boron in steel by AAS (atomic absorption spectrometry), ICPOES(inductively coupled plasma-optical emission spectrometry), ICP-MS (inductively coupled plasma/mass spectrometry). The volatile loss of boron of steel in sample digestion and the separation procedure for avoiding matrix effect by high concentration of iron are difficulties for determination of boron in steel. The method to determine boron in steel by ICP-MS was developed without volatilization of boron in sample digestion step with HNO3-NH4HF2 digestion method, and the additional separation process for avoiding matrix effect. Complete decomposition of steel with HNO3-NH4HF2 digestion method, and boron determination by ICP-MS in the matrix of high concentration of iron were possible. Quantitative recoveries of boron in certified standard steel by new method in this study were 103 to 111%, and the relative standard deviation is less than 5%. The method detection limit was 1.17 μg/g. 요 약: 최근 붕소를 철강에 첨가함으로써 철강의 성질을 개선시키는 여러 연구들이 알려져 있다. 이러 한 연구를 위하여 원자 흡광광도법, ICP-OES, ICP-MS에 의한 철강 중 붕소 분석 방법에 관한 연구들이 보고되고 있으며, 철강 중 붕소 정량 시 붕소의 휘발 손실 및 고농도 철 매트릭스로 인한 붕소 분석 방 해 등의 어려움이 알려져 있다. 이 연구에서는 붕소의 휘발 손실을 억제 가능한 철강 시료 분해 방법 및 매트릭스 분리과정 없이 ICP-MS에 의하여 철강 내 붕소를 정량할 수 있는 방법을 연구하고자 하였다. 질산-이플루오린화 암모늄을 이용하여 철강 시료 중 붕소의 휘발 손실을 억제하고 시료의 완전 분해가 가능하였으며, ICP-MS에 의하여 다량의 철 매트릭스 중 붕소 정량이 가능하였다. 서로 다른 붕소 함량 의 철강 표준물질을 대상으로 시료 분해 및 ICP-MS에 의한 붕소 정량 결과 회수율은 103~111%, 상대표 준편차는 5% 이하였으며, 방법검출한계(MDL)는 1.17 μg/g 이었다.

New Device of Continuous Flow System for Determination of Boron in Steel by Using Both Methods of Chemiluminescent Detection and Continuous Sample Flow Injection

For easy, rapid and economical analysis of steel sample, a continuous flow system was developed by both methods of chemiluminescence (CL) detection and continuous sample flow injection. The system was consisted of 4 channels and analytical time required was less than 30 sec and RSD was less than 2.8 % in 5 repeated runs by using the boron standard solution. Lower detection limit and range of determination were 3x10 -7 M and from 1.0x10 -6 M to 9.6x10 -4 M, respectively. Selectivity of the proposed system was good and interference by another foreign compounds such as AlCl3 and Ni(NO3)2 was negligible small in 1000 times higher concentration of their compounds to boron. In some real steel sample analyses, their determined values agreed with their certified ones, and then the reliabilities were less than 4.4 % in terms of relative error in 3 repeated tests. Additionally, concerning the background CL determination for real steel sample, the D-sorbitol solution should be changed to the purified water, since residual acid after the steel sample preparation might be existed in the system. Also, the steel sample solution should be adjusted to the higher pH than 4.

Flow Injection Fluorometric Determination of Boron in Steel with 2,3-Dihydroxynaphthalene Using Methanol as a Carrier Liquid

The size of the blank value is enumerated in one of the factor that influence the detection limit in the fluorescence determination method. The blank value in this case is brought about by excess reagent. Therefore, the some methods for removing the excess reagent were studied under the conditions of the stability of boron-complex. To remove the influence of excess reagent, the solvent–extraction method etc. is used beside a method of changing the pH. This study attempted a fluorescence determination of boron by flow injection analysis using the methanol as a carrier liquid. As a result, the amount of reagent decreased down to 1/15 compared to that of conventional method, because of decreasing the amount of water in the sample solution.The water in the sample solution suppressed the reaction between boron and 2,3-dihydroxynaphthalene (2,3-DHN). Therefore, the decrease of water tolerates the low concentration of 2,3-DHN. Under the optimum conditions, a calibration curve was drawn, which was linear over the range of 0 to 120 ppb. The relative standard deviation at 20 ppb B was 0.9% (n=6). For the determination of a trace amount of boron in steels, the on-line separation/preconcentration of boron from iron matrix (500 ppm) was performed by using resin (Amberlite IRA 743). The limit of B determination was 0.8 ppb (1.5 ppm in steels). The determination results for boron in standard steel materials showed good agreement with the certified values.

2,3-ジヒドロキシナフタレンを用いる鉄鋼中ホウ素のフローインジェクション蛍光分析

2,3-ジヒドロキシナフタレンを用いる鉄鋼中ホウ素のフローインジェクション蛍光分析

Evaluation of different sample introduction approaches for the determination of boron in unalloyed steels by inductively coupled plasma mass spectrometry

An extended study of different sampling introduction approaches using inductively coupled plasma mass spectrometry (ICP-MS) is presented for the determination of boron in steel samples. The following systems for sample introduction were applied: direct sample solution nebulization by continuous nebulization (CN) using a cross-flow nebulizer and with flow injection (FI), applied to 0.1% (m/v) and 0.5% (m/v) sample solutions, respectively; FI after iron matrix extraction, using acetylacetone–chloroform, and isotopic dilution (ID) analysis as the calibration method; FI with on-line electrolytic matrix separation; and spark ablation (SA) and laser ablation (LA) as solid sampling techniques. External calibration with matrix-matching samples was used with CN, SA, and LA, and only acid solutions (without matrix matching) with FI methods. When FI was directly applied to a sample solution, the detection limit was of 0.15 μg g −1, improving by a factor of 4 that was obtained from the CN measurements. Isotopic dilution analysis, after matrix removal by solvent extraction, made it possible to analyse boron with a detection limit of 0.02 μg g −1 and, with the on-line electrolytic process, the detection limit was of 0.05 μg g −1. The precision for concentrations above 10 times the detection limit was better than 2% for CN, as well as for FI methods. Spark and laser ablation sampling systems, avoiding digestion and sample preparation procedures, provided detection limits at the μg g −1 levels, with RSD values better than 6% in both cases. Certified Reference Materials with B contents in the range 0.5–118 μg g −1 were used for validation, finding a good agreement between certified and calculated values.

Determination of boron in steel by anion-exchange separation and ICP-AES

The determination of boron in steel was carried out by ICP-AES combined with anion-exchange separation. About 0.2 g of a steel sample was weighed in a quartz beaker and dissolved with a mixture of 2 cm3 of nitric acid, 1.5 cm3 of phosphoric acid and 4 cm3 of water by heating on a hot plate. Most of the nitric acid was evaporated off and the sample solution was transferred into a separatory funnel with 10 cm3 of 0.1 mol dm−3 nitric acid and water. About 3 g of iron(III) hydroxide oxide was dissolved in a mixture of 10 cm3 of hydrofluoric acid, 1 cm3 of 30% hydrogen peroxide and 50 cm3 of water by heating on a hot plate and added to the above sample solution. The sample solution was diluted to about 100 cm3 with water, allowed to stand for 1 h and then loaded onto an anion-exchange resin Bio-Rad AG1 column preconditioned by a fluoride solution. The iron in the sample solution passed through the column, while the boron was adsorbed as BF4− on the column and recovered with 6.5 mol dm−3 nitric acid. The effluent, containing boron, was treated with phosphoric, perchloric and nitric acids and diluted to 25 cm3 with water to be subjected to ICP-AES at 249.77 nm. The proposed method was successfully applied to the determination of boron in a steel-certified reference material, JSS 174-5, provided by the Japan Iron and Steel Federation. The detection limit was found to be 1.3 μg g−1 boron in steel.

Quantitative determination of boron in steel by solid state nuclear track technique

Trace amounts of boron present as impurity in steel can be accurately determined by measuring the α-yield in10B (n,α)7Li reaction, since this reaction has a very high cross section for thermal and epithermal neutrons while natural boron contains significant isotopic abundance of10B. The α-particles produced during10B (n,α)7Li nuclear reactions can be detected by solid state nuclear track detectors (SSNTDs) and the boron content and its distribution can be determined in a sample. The technique involves the simultaneous irradiation of unknown and known samples with thermal neutrons and recording the reaction products in SSNTDs as α-tracks. The α-tracks in the detectors are counted with the aid of an optical microscope after chemical etching. Boron concentration and distribution in the unknown sample is determined by counting and comparing the track density with that of standard sample of known boron concentration. The technique of SSNTDs has been applied by us to determine the distribution of trace amount of boron in commercial alloy steel using LR-115, CA80-15, CN-85 and CR-39 detectors. All these detectors pose various problems during reactor irradiation and etching. However, CR-39 has been found to be suitable for determining the magnitude and distribution of boron in steel. A brief description of the method and the optimum irradiation and etching conditions of various detectors for α-track revelation along with results for the estimation of boron in alloy steel are described in this paper.

Determination of Boron in Steels by On-line Flow Injection Cation Exchange Eliminating Matrix Inductively Coupled Plasma-Atomic Emission Spectrometry

A high performance of system was presented for the determination of boron in steels by on-line flow injection cation exchange eliminating matrix, followed by inductively coupled plasma-atomic emission spectrometry in this paper. The operating parameters were discussed and optimized. 50 mg/ml of iron matrix can be eliminated by the cation exchange column. Two standard steels and four synthetic standards were analyzed. The sensitivity and rate of analysis were improved compared with conventional separation methods.

Determination of boron in steel by an ICP emission spectrometric technique

A method was developed for the emission spectrometric determination of boron in steel using ICP excitation. Interfering effects of the matrix are avoided by pyrohydrolytic separation of boron. It is possible to determine boron from 1 mg/kg upwards.

Characteristics of Flow Injection Inductively Coupled Plasma Mass Spectrometry for Boron Analysis in Steels.

A method for the determination of Boron in steels by FI-ICP-MS is described. It is shown that flow injection (FI) can alleviate problems arising from high amounts of dissolved solids in Inductively Coupled Plasma Mass Spectrometry (ICP-MS) due to the capability to operate with microliter amounts of sample with a rapid sample rate. Sample dissolution was carried out in a microwave oven using diluted aqua regia (HCl+HNO3, 3+1) and high pressure digestion vessels, which gave notable advantages over conventional dissolution techniques, such as lower costs, greater volatile retention, reduced contamination and faster dissolution rates. The operating parameters in flow injection ICP-MS, such as carrier flow rate, nebulizer flow rate, and injection volume were established. The detection limit obtained when direct sample nebulization was used, with a 0.05% m/v Fe concentration, was 1.2 μg·g-1 B, compared to a detection limit of 0.2 μg·g-1 when the FI system was used with samples containing a higher concentration of dissolved solids (0.5% m/v Fe). The influence of the internal standard on precision and accuracy was studied and Beryllium was selected as the internal standard. The RSDs obtained for four peak area determinations of 200 μl injection volumes of a solution of 100 ng·ml-1 B in the presence of 0.5% m/v Fe were below 1.5%. The accuracy of the method proposed was verified by analyzing Reference Materials (EURONORM-CRM 097-1; BCS 456, 457 and 460; NBS 361, 363 and 365), using an external calibration system with calibration samples, prepared from a standard Boron solution, in the same acid medium as the test sample solutions.

Volatilization of methyl borate in iron matrix. Determination of boron in steel by ICP atomic emission spectrometry

A rapid and reliable method for the determination of boron by ICP—AES in steels is described. The procedure is based on a discontinuous generation of methyl borate, in concentrated sulphuric acid and phosphoric acid medium, after injecting 45 μl of methanol in 20 μl of sample. The gaseous methyl borate and excess methanol are fed into the ICP torch via the intermediate tube by a flow of 430 ml/min Ar carrier gas, without disturbing the discharge. This work simplifies drastically the existing methodology of boron analysis in steels. Acid-soluble boron has been determined, but acid-insoluble boron can also be determined. The determination is carried out without iron interferences, with a reproducibility of 1.90% r.s.d. for a concentration of 20 μg/ml, and an absolute detection limit of 20 ng of total boron, working with a solution volume of 20 μl.

Boron determination in steels by inductively coupled plasma atomic emission spectrometry. Comparative study of spark ablation and pneumatic nebulization sampling systems

An experimental study for the determination of boron in steels by inductively coupled plasma atomic emission spectrometry is presented. A comparison is made of spark ablation and pneumatic nebulization (after microwave digestion) sampling systems. A one-step microwave digestion procedure for total boron content using diluted aqua regia(HCl + HNO3, 3 + 1) and high pressure vessels was developed. The influence of microwave power and time on the dissolution of boron compounds is discussed. The strongest available conditions (0 Ω, 600 V, 600 Hz) were required for spark ablation sampling. The stability of spark sampling during the spark ablation-ICP process was tested by plotting iron and boron emission versus sparking time. The iron content of collected and dissolved spark-produced particles was analysed and showed that the amounts of aerosol from different boron steels samples during 90 s sparking processes were fairly similar. The analytical performance of both systems was evaluated. Using pneumatic nebulization, after microwave digestion of the sample, a detection limit for boron of 2.6 µg g–1 and overall relative standard deviation (RSD) values of 1–3.5% were found. For spark ablation the detection limit for boron was 0.65 µg g–1, the overall RSD ranging from 0.5 to 1.5%. A comparison of the data for British Chemical Standards (BCS) Certified Reference Materials (CRMs) Carbon Steel Residual Series (Group B) and Spectroscopic Standard (SS) 456/1 to 460/1, indicated that the accuracy of both methods was satisfactory.

Determination of boron in steels and iron salts by HPLC.

陰イオン交換カラムを用いるHPLCによるホウ素の高感度定量法を応用して,鉄鋼,鉄塩中のホウ素を定量した.ホウ酸の形で存在するホウ素は水溶液中でクロモトロープ酸と反応して錯陰イオンを形成する.この錯陰イオンと過剰のクロモトロープ酸とを陰イオンカラムにより分離し,350nmで検出した.ホウ素とクロモトロープ酸との反応性を高めるため,オクチルトリメチルアンモニウム塩を加えpH4.8で錯イオンを形成させた後,HPLC装置に注入した.溶離液には過塩素酸ナトリウムを用いた.検出限界はホウ素量0.006μg/mlであり,分析速度は1時間当たり約17試料であった.鉄イオンの影響はEDTAを添加することにより除くことができた.

Rapid technique for distillation of methyl borate for ICP atomic-emission spectrometric determination of boron in steel

The analysis time for determination of boron in steel can be remarkably shortened by simultaneous distillation of methyl borate and evaporation of the distillate for analysis by ICP atomic-emission spectrometry. Methyl borate, distilled with a large quantity of methanol, is collected in 4% sodium hydroxide solution heated in a water-bath at 90°. As the boiling point of the mixture of absorption solution and methanol is lower than 90°, the solvent mixture is easily evaporated. The limit of detection corresponds to 35 ng of boron in 0.5 g of steel.

パルス分布測光-発光分光分析法による鋼中ボロンの定量

パルス分布測光-発光分光分析法による鋼中ボロンの定量

Solvent extraction-spectrophotometric determination of boron in steel with 2,4-dinitronaphthalene-1,8-diol and Brilliant Green

On the basis of previous work, a solvent extraction procedure has been applied to the determination of boron in steel. The boron (as boric acid) is converted to the monovalent complex anion, BR2–(where H2R is 2,4-dinitronaphthalene-1,8-diol), in acetic acid medium, extracted as a coloured ion associate with Brilliant Green into toluene and determined spectrophotometrically. Steel samples were dissolved in a mixture of dilute hydrochloric acid and hydrogen peroxide and large amounts of iron and other metal ions in the solution were removed either by solvent extraction with 4-methylpentan-2-one or by precipitation as hydroxides or oxinates. Micro amounts of boron in steel samples (0.0013–0.012%) were determined.

Indirect atomic-absorption determination of boron by solvent extraction as tris(1,10-phenanthroline)cadmium tetrafluoroborate

An indirect atomic-absorption method for boron has been developed. Boric acid is converted into tetrafluoroborate and extracted into nitrobenzene with Tris(1,10-phenanthroline)cadmium(II). The cadmium in the extract is determined by its atomic-absorption at 228s>d8 nm. A fivefold molar excess of the cadmium chelate is necessary for the extraction from pH 4>d3–6>d0 medium. The sensitivity for boron is thus made about the same as that of cadmium, 0>d005 ppm. Metal ions that react with fluoride or phenanthroline interfere. A procedure is described for determination of boron in steel.