Molecular emission cavity analysis (meca)—a new flame analytical technique: Part III. The determination of boron

Two highly selective methods are described for the determination of boron by molecular emission cavity analysis. In one, boron (>0.1 p.p.m.) is extracted as its 2-ethylhexane-1,3-diol chelate into methyl isobutylketone; 5-80 ng of boron in 5 μl of the extract is determined by injection into the MECA cavity. In the other, boron (2-30 μl) is converted into volatile methyl borate, and carried into the rear of the cavity by a stream of nitrogen. In both methods, the emission intensity at 518 nm, stimulated by a hydrogen-nitrogen-oxygen flame, is measured. Of the other ions tested, none interfered in the volatilization procedure, and only fluoride ( ? 100 mg) interfered in the extraction method. The precision is ±4%.