Higher-order derivative spectrophotometry in environmental analytical chemistry.

Higher-order derivative spectrophotometry (HODS) is a very good tool for the fine-resolution of spectra and other electric signals. This method allows one to separate superimposed curves for quantitative measuring. In the following, examples are given for the estimation of pollutants in water, air and soils which demonstrate the advantages of the HODS. This also applies to difficult problems in environmental analytical chemistry. In detail, we discuss the simultaneous estimation of aniline and phenol in waste water, the quantitative determination of PCP in polluted drinking water, phenol in turbid samples, the identification of aromatic amides and phenols in air after absorption in solvents and, last but not least, the study of Ni2+ adsorbed on bentonite powder.