Fluoride Interference in the Determination of Boron by Inductively Coupled Plasma Emission Spectroscopy

Abstract

Boron determination in borophosphosilicate glass films by the ICP-AES or ICP-MS technique can be performed after dissolution of the sample in HF solution. However, addition of HF to boric acid standard solution can cause a drift in the slope of the calibration curve. The signal change was correlated with the kinetics of the borontetrafluoride complex formation reaction. The mechanism was explained by the selectively increased boron transport into the plasma, which was caused by the more efficient diffusion of borontrifluoride gas through the aerosol particles into the nebulizer gas. With the kinetics of borontetrafluoride complex formation taken into consideration, an accurate and precise method was developed for the determination of boron in BPSG films.

Boron Determination—A Review of Analytical Methods

“…There are several types of plasma (125), namely, the direct current (DCP) (126,127), the inductively coupled plasma (ICP) (4,6,128), the microwave induced plasma (MIP) (129) and the glow discharge plasma (GDP) (130). Plasmas have been generated from a number of gases or their mixtures (125, 131); however, most commercial plasma-source instruments use an argon ICP (i.e., ICP generated from argon) for ionization.…”

“…The presence of HF in a sample increases B transport into the plasma and B emission signal (4). The presence of HF favors the formation of boron trifluoride, which has higher transport efficiency as aerosol particles than boric acid.…”

“…Wet ashing is performed by placing samples and strong mineral acids such as HNO 3 , H 2 SO 4 , HClO 4 , or their mixtures in digestion containers (ideally B-free) and heating (usually with a reflux system) to decompose the sample. The use of Bcontaining digestion containers such as borosilicate glass could contaminate the sample and lead to higher blank values.…”

“…The lead containers were pinched-sealed following evacuation for neutron irradiation. A static mass spectrometer was used to measure 4 He (from 10 B) and 3 He (from 6 Li) generated by the NA reaction. The error rate at ¢1 ppm B concentration was 1-5% but at 6 ppb B the error rate increased to 75%.…”

“…Boron carbide, used as control rods, is an important nuclear material (3). The flow and other properties such as etch rates of borophosphosilicate glass films are directly dependent on their B and P concentrations (4). A small change in B concentration/content can influence the properties of semiconductor-grade silicon (5) and physical properties such as hot workability, hardenability, and creep resistance of steel and alloys (6)(7)(8).…”