Characterization of toasted cereal flours from the Canary Islands (gofios).

In this work, different types of gofio produced in the Canary Islands were characterized on the basis of physico-chemical parameters as well as spectral features. An overall of 7 physico-chemical parameters (moisture, ash, pH, Cu, Fe, Mn and Zn) were determined in 64 samples from different cereals and legumes, and IR spectra of all samples were registered. The chemometric processing of both, metal ions contents determined by atomic absorption spectrophotometry, and the MIR spectra, with various techniques including cluster analysis, principal component analysis, and discriminant analysis enabled the accurate characterization and classification of the gofio samples according to the grain used in their obtaining process.

Application of PLS regression to fluorimetric data for the determination of furosemide and triamterene in pharmaceutical preparations and triamterene in urine.

Multivariate calibration methods that use fluorescence data for the simultaneous determination of furosemide and triamterene were developed. One of the most salient advantages of them is that the vast amount of information provided by the whole spectrum of the sample is not required. This makes analyses simple and fast. The methods require selecting chemometric parameters such as the specific spectral region and number of factors to be used. Both spectral region and number of factors are selected, simultaneously, by minimising the prediction residual error sum of squares (PRESS). The proposed methods were used for the simultaneous determination of the two drugs in real samples (pharmaceutical preparations) with no excipient separation pre-treatment, with furosemide and triamterene contents of 1.68E-3 to 4.31E-2 and 1.03E-3 to 3.12E-2mugml(-1), respectively; as well as that of triamterene at concentrations of 5.00E-4 to 5.80E-3mugml(-1) in urine samples. The ability to construct the calibration validation sets directly from the urine samples itself avoids the need to consider matrix interferences or to pre-treat the sample and/or separate some analytes The results were quite good in all cases.