Isotope Dilution Analysis for Flow Injection ICPMS Determination of Microgram per Gram Levels of Boron in Iron and Steel after Matrix Removal

Abstract

Isotope dilution analysis using flow injection inductively coupled plasma mass spectrometry was applied to determine low boron contents in iron and steel samples. Sample dissolution was carried out in a microwave oven with an HCl, HNO3, and H2SO4 acid mixture and high-pressure digestion vessels. A solvent extraction procedure using acetylacetone−chloroform was applied for the separation of the iron matrix as the sulfate (pH = 1.4 ± 0.1). Test solutions corresponding to 50 mg mL-1 of sample, with the total boron content and iron contents below 1 μg mL-1, were obtained. Flow injection was used as a sampling system to minimize problems arising from the total salt concentration of the test solutions. This method made it possible to analyze boron in iron and steel at submicrogram per gram levels. The detection limit (3σ), in micrograms of boron per gram of sample, was 0.02, and the precision for concentrations above 10 times the detection limit was better than 1%. Accuracy was tested with eight standard reference materials with boron certified values in the 0.5−10 μg g-1 range.

Effect of Boron on Human Health

“…Hence, the isotope dilution method, the most precise approach in the quantitative determinations, can be easily performed using ICP-MS [29]. ICP-MS has been used for the determination of boron in many matrices including high-purity quartz [30], iron and steel with isotope dilution [31], body fluids with isotope dilution [32]. Serious memory effects and matrix interferences are some of the problems found in the use of ICP-MS in boron determination.…”

Determination of Trace Amounts of Boron in Steels by On-line Reaction/Concentration/Separation Using an Anion-exchange Column

“…This value is almost the same as that obtained by an isotope-dilution ICP-MS measurement with an off-line matrix removal treatment (0.02 μg g -1 ). 5 Also, the detection limit can be further lowered by introducing a larger volume of the sample solution, as mentioned in our earlier report. 14 Overall, the proposed method can be used to determine trace amounts of boron with high precision and accuracy in steel samples.…”

“…[1][2][3][4] A flow-injection system with extraction treatment has also been coupled with ICP-MS to remove the effects of sample matrices for the determination of sub-μg g -1 levels of boron in iron and steel. 5 On the other hand, the high-performance liquid chromatography (HPLC) methods with a spectrophotometric or a fluorometric detector have been proposed for determining boron in steels. [6][7][8][9][10] However, the processes of special separation and/or preconcentration were often used to improve the detection sensitivity.…”

Determination of Boron Steel by Isotope-Dilution Inductively Coupled Plasma Mass Spectrometry after Matrix Separation

“…ICP-MS has been employed for the determination of boron in geological, 4 biological, 5 and steel 6,7 samples. Despite such salient features, ICP-MS suffers from both spectral and non-spectral interferences in most applications.…”