BORON ANALYSIS IN BIOLOGICAL-MATERIAL - MICROWAVE DIGESTION PROCEDUREAND DETERMINATION BY DIFFERENT METHODS

Investigations were made on the determination of boron in biological m aterial. A procedure using the microwave digestion technique was optim ised. The analyses were performed by photometry with azomethine-H, flu orimetry with carminic acid, inductively coupled plasma atomic emissio n spectrometry and inductively coupled plasma mass spectrometry. The m atrix interferences, the interferences caused by iron and the detectio n limits were investigated for these methods. Determinations were perf ormed for plant material, wheat, milk, meat and blood plasma. Recoveri es and precision of all methods were studied. To test accuracy and pre cision, four NBS reference materials were analysed and the results com pared with the values in literature. Good recoveries were found with a ll methods, except the fluorimetric technique. The boron content found in the NBS standard reference materials agreed well with data reporte d before. Best precision was obtained for the two ICP methods. The azo methine-H method gave good results when material of high boron content was analysed. With the carminic acid method no reliable results were achieved.