Matrix with additional diodes

Figure 50. Liquid crystal matrix array with additional diodes.

A multiresidue preparation technique—MSPD—has also been applied to the analysis of CAP residues in meat samples. Two fractions were collected by elution with methylene chloride and ethyl acetate. No additional purification was necessary. Diode assay detection and fluorescence detectors were recommended for the multiresidue analysis of sulfonamides, benzimidazoles, nicarbazin, furazolidone, and CAP. The percentage recoveries and linearity of the method were evaluated. The method was linear from 50 to 250 /tg/kg of CAP. Not only do the authors recommend the MSPD multiresidue procedure for HPLC analysis, but it could be associated with several detection modes, such as immuno- or receptor assays. The MSPD technique represents a new approach in the field of biological-matrix extraction and provides a great possibility for the analysis of a wide range of compounds (20). 

The resolution of a multicomponent system involves the description of the variation of measurements as an additive model of the contributions of their pure constituents [1-10]. To do so, relevant and sufficiently informative experimental data are needed. These data can be obtained by analyzing a sample with a hyphenated technique (e.g., HPLC-DAD [diode array detection], high-performance liquid chromatography-DAD) or by monitoring a process in a multivariate fashion. In these and similar examples, all of the measurements performed can be organized in a table or data matrix where one direction (the elution or the process direction) is related to the compositional variation of the system, and the other direction refers to the variation in the response collected. The existence of these two directions of variation helps to differentiate among components (Figure 11.1). 

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