Antonio L. Magrì

Data-fusion for multiplatform characterization of an Italian craft beer aimed at its authentication.

Five different instrumental techniques: thermogravimetry, mid-infrared, near-infrared, ultra-violet and visible spectroscopies, have been used to characterize a high quality beer (Reale) from an Italian craft brewery (Birra del Borgo) and to differentiate it from other competing and lower quality products. Chemometric classification models were built on the separate blocks using soft independent modeling of class analogies (SIMCA) and partial least squares-discriminant analysis (PLS-DA) obtaining good predictive ability on an external test set (75% or higher depending on the technique). The use of data fusion strategies - in particular, the mid-level one - to integrate the data from the different platforms allowed the correct classification of all the training and validation samples.

Tracing the origin of extra virgin olive oils by infrared spectroscopy and chemometrics: A case study

In this paper, the potential of coupling mid- and near-infrared spectroscopic fingerprinting techniques and chemometric classification methods for the traceability of extra virgin olive oil samples from the PDO Sabina was investigated. To this purpose, two different pattern recognition algorithm representative of the discriminant (PLS-DA) and modeling (SIMCA) approach to classification were employed. Results obtained after processing the spectroscopic data by PLS-DA evidenced a rather high classification accuracy, NIR providing better predictions than MIR (as evaluated both in cross-validation and on an external test set). SIMCA confirmed these results and showed how the category models for the class Sabina can be rather sensitive and highly specific. Lastly, as samples from two harvesting years (2009 and 2010) were investigated, it was possible to evidence that the different production year can have a relevant effect on the spectroscopic fingerprint. Notwithstanding this, it was still possible to build models that are transferable from one year to another with good accuracy.

Application of differential scanning calorimetry to the study of drug-excipient compatibility

Abstract Differential scanning calorimetry (DSC) has been used to investigate drug-excipient interactions and, in consequence, their compatibility. In particular, binary mixtures of nefazodone with magnesium stearate and lactose, and fosinopril with the same excipients were prepared and analysed, after proper conditioning. The thermoanalytical results were compared with those obtained by spectroscopic (UV, IR) and chromatographic (HPLC) analysis. We believe that changes in DSC runs cannot always be a sufficient condition to prove that some interaction occurs between drug and excipient during storage at room temperature. Some data on the spectroscopic characteristics of nefazodone and fosinopril drugs and their thermal behaviour are also reported.

Determination of fosinopril in pharmaceutical formulations containing hydrochlorothiazide by multiwavelength UV spectrophotometry

A sensitive, simple, rapid and precise method for the simultaneous determination of fosinopril (FOS) and hydrochlorothiazide (HCT) in pharmaceutical formulations is presented. These active ingredients are extracted in aqueous solution and measured by multiwavelength UV spectrophotometry using the program QUEST. HCT acts as an internal standard to verify the accuracy of the analysis. Some aspects of the chemical, spectroscopic and thermoanalytical behaviour of FOS are also reported.

Classification and Class-Modelling

Abstract This chapter describes the basic theory about classification, starting from a general description of the different approaches to classification and then illustrating in detail the principal methods which are used in the framework of assessment of food quality. Examples of application of the methods to different data sets are also provided.

Quantitation of tr-cinnamaldehyde, safrole and myristicin in cola-flavoured soft drinks to improve the assessment of their dietary exposure.

Quantitation of tr-cinnamaldehyde, safrole and myristicin was carried out in 70 samples of cola-flavoured soft drinks purchased in eight European countries with the purpose of assessing the variability in the levels of these substances. Results indicated a limited variability in the content of the three substances: the ratio between the 90th and the 10th percentile concentration amounted to 21, 6 and 13 for tr-cinnamaldehyde, safrole and myristicin, respectively. The uncertainty in the assessment of dietary exposure to these substances due to the variability of their level in cola-flavoured drinks was low. Based on these analytical data and on refined food consumption data, estimates of exposure to safrole associated to cola drink consumption, along with Margin of Exposure (MOE) values, were obtained. For high consumers of cola-flavoured soft drinks in certain age groups, within some European countries, MOE values lower than 10,000 resulted, MOE values of 10,000 or higher having been stated by the EFSA as a quantitative criterion to identify low concern from a public health point of view and low priority for risk management actions. The lowest MOE values, from 1900 to 3000, were observed for children and teen agers in the United Kingdom and Ireland.

The thermal decomposition reactions of [Co(en)n(phen)m]Cl3 complexes

Abstract The thermal behaviour of [Co(en)n(phen)m]Cl3 complexes has been studied using thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA) in air, nitrogen and oxygen atmospheres. The effect of the stoichiometry of the complexes and that of the gas atmosphere in the furnace chamber on the thermal decomposition reaction is evidenced and discussed. The following thermal stability order has been found [Co(en)3]Cl3 ≌ [Co(en)2(phen)]Cl3 > [Co(en)(phen)2]Cl3 ⪢ [Co(phen)3]Cl3

Evaluation of the moisture and ash contents in wheat mills by multistep programmed thermogravimetry

Abstract The determination of the moisture and ash contents in wheat mills was developed using multistep programmed thermogravimetric analysis. Preliminary research to determine the most suitable analytical conditions (carrier gas and flow rate, furnace temperature, isothermal time, type and weight of sample and size of particles) was also carried out. Commercial flours milled from soft and hard wheats with a wide range of fibre content were analysed using both the proposed method and the Italian official methods. The same results were obtained from all these methods. Nevertheless, the thermogravimetric method has some advantages: the analysis takes place on the same sample; it requires very small samples; and it is easy and rapid.

Chromium(III) Complexes with Diethylentriaminepentaacetic Acid

Abstract Complex formation by chromium(III) with diethylentriaminepentaacetic acid (DTPA) has been studied by potentiometry and spectrophotometry. In equimolar solutions or with a ligand excess, complexation is practically complete at pH > 1 and protonation equilibria have been calculated. Molar absorbtivities of the different species have been evaluated. Equilibrium constants for complex formation have been calculated in 1 mol dm−3 (Na,H)ClO4 at 20°C.

The thermal decomposition reactions of bis-(pyridine-2-aldoxime)-copper(II) complexes

The thermal properties of some complexes of copper(II) with pyridine-2-aldoxime (HPAO), where the ligand appears either as the ion (PAO−) or as a neutral molecule, were determined in vacuo and in dynamic nitrogen and oxygen gas atmospheres. The study was carried out by thermoanalytical (TG, DTG. DTA), spectroscopic and spectrometric (UV-visible, IR, diffuse reflectance, mass) techniques.The initial decomposition temperature is influenced by the number of acid hydrogens in the complex; the thermal stability sequence in vacuo is: [Cu(PAO)2H]Cl > [Cu(PAO)2H2]Cl2 > [Cu(PAO)2]The thermal decomposition reactions occur in several separate steps, the first of which gives rise to partial ligand decomposition, the reduction of copper(II) to copper(I), and the conversion of the residual pyridine-2-aldoxime into acid amide.ZusammenfassungDie thermischen Eigenschaften einiger Komplexe von Kupfer(II) mit Pyridin-2-aldoxim (HPAO), in denen der Ligand entweder als Ion (PAO−) oder als neutrales Molekül vorliegt, wurden im Vakuum und in dynamischer N2- und O2-Atmosphäre ermittelt. Zur Untersuchung wurden thermoanalytische (TG, DTG, DTA) und spektrometrische (UV-sichtbar, IR, diffuse Reflektionsspektrophotometrie, Massenspektrometrie) Techniken herangezogen. Die Temperatur, bei der die Zersetzung beginnt, wird durch die Zahl der sauren Wasserstoffatome im Komplex beeinflußt; für die thermische Stabilität im Vakuum gilt die Reihenfolge [Cu(PAO)2H]Cl > [Cu(PAO)2H2]Cl2 > [Cu(PAO)2]. Die thermischen Zersetzurigsreaktionen verlaufen in mehreren diskreten Schritten, wobei der erste von diesen eine partielle Zersetzung des Liganden, die Reduktion von Kupfer(II) zu Kupfer(I) und die Konversion des verbleibenden Pyridin-2-aldoxims in das Säureamid in sich einschließt.РезюмеВ вакууме и динамичес кой атмосфере кислор ода исследованы термиче ские свойства некоторых к омплексов двухвален тных меди и пиридин-2-альдоксима (Н РАО), в которых лиганд нахо дится как в ионной фор ме (РАО-), так и в виде нейтральной м олекулы. Исследование было пр оведено термоаналит ическими (ТГ, ДТГ, ДТА) методами, электронными спектр ами поглощения в УФ- и в идимой области, ИК спектроск опией, масс-спектроскопией и спектроскопией диф фузного отражения. Начальная температура разложения зависит о т числа кислотных вод ородов в комплексе, а термоуст ойчивость их в вакууме может быт ь расположена в ряд [Cu(PAO)2H]CI > [Cu(PAO)2H2]Cl2 > [Cu(PAO)2] Реакции термическог о разложения протека ют в несколько стадий, пер вая из которых вызывает частичное р азложение лиганда, восстановление двух валентной меди до одн овалентной и превращение оставш егося пиридин-2-альдок сима до амида кислоты.