Correspondence analysis and adsorbate selection for chemical sensor arrays

Abstract

SUMMARYCarey et a/. utilized principal components analysis (PCA) to analyze frequency shift data obtained from piezoelectric sensors formed by coating quartz crystals with 27 different GC stationary phases and tested using 14 analytes. The objective of the analysis was to determine an optimal reduced set of coatings for detection of the analytes. The results were correlated with those obtained from cluster analysis. In this paper the data are re-analyzed using correspondence analysis (CA). The advantage of using CA include a symmetric treatment of sensor coatings and analytes and better identification of the representation of the analytes in terms of the detection components. The results obtained by the conjunctive use of PCA, a varimax rotation and cluster analysis were obtained by CA.

Correspondence Analysis on a Space-Time Data Set for Multiple Environmental Variables

“…In the geostatistical context, applications of CA are relatively new. Avila et al in [9] and [10] analyzed a data set consisting of the concentrations of chemical elements measured in a lake; Dutot et al [11] applied this method to an aerosol collected in a simple atmospheric environment; Jiménez-Espinosa et al [12] used CA on 602 soil samples taken in a region of NW Spain to identify geochemical patterns and anomalies.…”

Array‐Based Sensors

“…17.10. As has been reported in the case of monodimensional sensors [85,86], the idea is to select the sensors with the maximum contribution to each of the PCs of statistical significance. Thus, after the PCA is applied to the original dataset, a sensor array with m elements will be reduced to a maximum number of sensors equal to the number PCs with eigenvalues >1, according to Kaiser's rule.…”

Multisensor systems for gas analysis: optimization of arrays for classification of pharmaceutical products

“…If the analysis time will be fixed under the constant velocity of the gas flow, then the change of the crystal frequency is directly proportional to the analyte concentration in the gas flow. It is evident that the various processes can lead to the violation of the conditions in which the equation (4) was obtained. Among them adsorption of the mixture on the walls, fluctuations of the temperature, pressure, carrier gas velocity, etc.…”

“…The important place among such systems is occupied by selective sensors aimed at the single components of gas mixtures sensors of oxygen, hydrogen as well as other constituents of gas mixtures; these systems use the concept of specific sensors built on the principal one gas one sensor. Despite wide spectra of available sensors, they cant provide the respective description of the multicomponent mixtures that are characteristic for the chemical environment of the natural origin [4,5]. Besides, the creation of highly selective coatings sensitive only to the specific molecules, is practically impossible, because the compounds presenting the same chemical class have functional groups of the similar spatial structure with the close physical and chemical properties.…”