DETERMINATION OF BORON IN FERTILIZERS BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY - STUDIES OF SOME SPECTRAL INTERFERENCES AT DIFFERENT WAVELENGTHS

The most sensitive analytical wavelengths of boron cannot be used in t he determination of boron in fertilizers by inductively coupled plasma -atomic emission spectrometry because of spectral interference by pota ssium, phosphorus, and iron. For the 4 wavelengths of boron investigat ed, it was noticed that, at the same wavelength, the pattern of spectr al interference changes according to fertilizer composition. The spect ral interference patterns at the 4 analytical boron wavelengths were s tudied by adding matrix elements typically found in fertilizers to rea l fertilizer samples. When revels of added matrix elements correlate l ess than 0.2 to each other, the effect of added matrix elements on bor on determination can be calculated by multiple linear regression. The best analytical wavelength for determination of boron in fertilizer is 208.959 nm. If wavelength is selected only according to calibration d ata, without doing interference studies, the best wavelength should be 249.773 nm. Multiple linear regression in conjunction with experiment al design may be used to determine the best analytical wavelength for a sample matrix under analysis, examine the interference elements, and verify the concentration detected.