Multivariate bioassay

Principal components analysis can also be used in the case when the compounds are characterized by multiple activities instead of a single one, as required by the Hansch or Free-Wilson models. This leads to the multivariate bioassay analysis which has been developed by Mager [9]. By way of illustration we consider the physicochemical and biological data reported by Schmutz [41] on six oxazepines... 

To standardize the multivariate bioassay-derived data and facilitate their integration in the index, toxicity data are first converted into Toxic Units (TU), which are dimensionless ratios originally defined as the actual concentration of a particular toxic substance, divided by the incipient lethal concentration for that substance (Sprague and Ramsay, 1965). A similar term can be used to define the toxicity potential of a sediment sample, whereby ... 

The sediment from Amerikahaven (site 10) was found to contain unexpectedly low contaminant levels during sampling in 1996 (see also De Boer et al., 2001). This was attributed to repeated dredging activity. The sediment was therefore sampled a second time in September 1997 at a non-dredged site. Analysis of this sediment showed considerably higher contaminant levels. These results are considered more representative of this location and were therefore used instead of the 1996 data in the multivariate statistical analysis of biomarker data. Sediment bioassays were however conducted with the material collected in 1996 and these data for location no. 10 were used for multivariate analysis when sediment chemistry was included. 

Shaw, J.L., Manning, J.P. (1996). Evaluating macroinvertebrate population and community level effects in outdoor microcosms use of in bioassays and multivariate analysis. Environmental Toxicology and Chemistry, 15 508-617. 

Ahlf, W. and Wild-Metzko, S. (1992) Bioassay responses to sediment elutriates and multivariate data analysis for hazard assessment of sediment-bound chemicals, Hydrobiologia, 235, pp. 415-418. 

See also-. Bioassays Overview. Chemometrics and Statistics Multivariate Calibration Techniques. Infrared Spectroscopy Near-Infrared. Liquid Chromatography Size-Exclusion Liquid Chromatography-Mass Spectrometry Liquid Chromatography-Nuclear Magnetic Resonance Spectrometry. Pharmaceutical Analysis Drug... 

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