Ion-exchange separation and spectrophotometric determination of boron in geological materials

Prompt ..gamma.. rays from thermal neutron induced nuclear reactions have been used to measure trace quantities of B and Cd in industrial and standard materials. The technique provides a rapid nondestructive analysis for > 0.05 ..mu..g of B. Repetitive analyses show the method to have a precision of 5%. The presence of large quantities of Na degrades the accuracy and precision of the B analysis. The technique also provides a method for the determination of Cd although it is not sufficiently sensitive to provide a practical alternative to more conventional methods.

Nondestructive determination of boron and cadmium in environmental materials by thermal neutron-prompt .gamma.-ray spectrometry

A prompt-gamma neutron activation technique has been developed using the (n, γ) apparatus situated at the O degree through-tube of the Imperial College CONSORT II Reactor with a thermal neutron flux at the target position of approximately 2×106 n cm−2 sec−1, and a Compton-suppression system involving a lithium-drifted germanium (Ge(Li)) detector and a sodium iodide anti-Compton shield. Boron levels of 1–5 μg g−1 (detection limit 0.05 μg B for 10,000 sec period of measurement) can be attained using the Compton-suppression system with graphical inter-polation correction for the 472 keV sodium-ray peak contribution to the Doppler-broadened 478 keV boron gamma-ray peak resulting from the10B(n, α)7Li reaction. Very good agreement is reached for boron levels compared using this system for various Standard Reference Materials and other published values. Measurement of the boron content of bone and tooth samples from rheumatoid arthritis individuals shows lower levels, (p<0.05); 16.13±7.53 μg g−1, when compared with a control population; 19.79±4.18 μg g−1. A positive correlation existed between the boron content of bone and tooth material for each study group. Results indicate that boron availability may be associated with rheumatoid arthritis.

The determination of boron in biological materials by neutron irradiation and prompt gamma-ray spectrometry

Spectrophotometric determination of boron in iron and steel with curcumin after separation by 2-ethyl-1,3-hexanediol-chloroform extraction.

The reaction of the tetrafluoroborate anion with Victoria blue 4R (VB4R) reagent was investigated, and a new, simple, rapid and sensitive method was developed for the spectrophotometric determination of boron. The method is based on the reaction of boric acid with fluoride, which forms the tetrafluoroborate anion, and that is followed by the extraction of with VB4R into benzene and subsequent spectrophotometric detection. The optimum conditions for the conversion of boron to tetrafluoroborate anion as well as for complex formation and extraction of with VB4R were found. The molar absorptivity of the investigated complex is 9.6 × 104 L mol−1 cm−1 at 610 nm. The absorbance of the coloured extracts obeys Beer's law in the range 0.03–0.55 mg L−1 of B(III). The limit of detection calculated from a blank test (n = 10; P = 0.95) based on 3 s is 0.02 mg L−1 of B(III). Under appropriate extraction conditions, the majority of metals (excluding probably tantalum and some others) did not form extractable fluoride com...

S. Matsushita

Papers

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