Rapid and mobile determination of alcoholic strength in wine, beer and spirits using a flow-through infrared sensor

<p>Abstract</p> <p>Background</p> <p>Ever since Gay-Lussac's time, the alcoholic strength by volume (% vol) has been determined by using densimetric measurements. The typical reference procedure involves distillation followed by pycnometry, which is comparably labour-intensive and therefore expensive. At present, infrared (IR) spectroscopy in combination with multivariate regression is widely applied as a screening procedure, which allows one to determine alcoholic strength in less than 2 min without any sample preparation. The disadvantage is the relatively large investment for Fourier transform (FT) IR or near-IR instruments, and the need for matrix-dependent calibration. In this study, we apply a much simpler device consisting of a patented multiple-beam infrared sensor in combination with a flow-through cell for automated alcohol analysis, which is available in a portable version that allows for on-site measurements.</p> <p>Results</p> <p>During method validation, the precision of the infrared sensor was found to be equal to or better than densimetric or FTIR methods. For example, the average repeatability, as determined in 6 different wine samples, was 0.05% vol and the relative standard deviation was below 0.2%. Accuracy was ensured by analyzing 260 different alcoholic beverages in comparison to densimetric or FTIR results. The correlation was linear over the entire range from alcohol-free beers up to high-proof spirits, and the results were in substantial agreement (R = 0.99981, p < 0.0001, RMSE = 0.279% vol). The applicability of the device was further proven for the analysis of wines during fermentation, and for the determination of unrecorded alcohol (i.e. non-commercial or illicit products).</p> <p>Conclusions</p> <p>The flow-through infrared device is much easier to handle than typical reference procedures, while time-consuming sample preparation steps such as distillation are not necessary. Therefore, the alcoholic strength can be economically and quickly controlled (requiring less than 60 s per sample). The device also gives the opportunity for mobile on-site control in the context of labelling control of wine, beer and spirits, the process monitoring of fermentations, or the evaluation of unrecorded alcohols.</p

Biogeochemistry, grain size and mineralogy of the Central and Southern Adriatic Sea sediments: a review.

Volume 26 Supplement 1, January 2010

Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea)

The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria rodriguezii; (ii) the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii) the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface) with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions

Desarrollo y validación de un método espectrofluorométrico para la determinación de furosemida en formas farmacéuticas sólidas

El presente trabajo tiene como objetivo desarrollar y validar un método analítico alterno, por espectrofluorometría, para el control de calidad de la Furosemida en formas farmacéuticas sólidas, basado en la fluorescencia nativa que presenta la molécula en medio ácido (?Exc.= 280nm y ?Emi.= 410nm). El método permite determinar la Furosemida en una solución amortiguadora de ácido clorhídrico-cloruro de potasio 50mM (pH 2,0), en el intervalo de 1,45x10-7 a 1,51x10-5 mol L-1 (4,5 a 5000 ng mL-1), con un límite de detección estimado de 4,84x10-8 -mol L-1 (1,5 ng mL-1). El método propuesto presenta como ventajas competitivas frente al método oficial reportado en la Farmacopea de los Estados Unidos (USP 29): su simplicidad, el bajo costo y una frecuencia de análisis cercana a las 20 muestras por hora.15-26cuatrimestreThe aims of this work is to develop and validate an alternative analytic method by spectrofluorometry for the quality control of Furosemide in solid pharmaceutical forms based on the native fluorescence of the molecule in acidic medium (?Exc.= 280nm and ?Emi.= 410nm). This method allows to determine Furosemide in a buffer solution of potassium chloride-hydrochloric acid 50 mM (pH 2.0) in a range of 1.45x10-7 to 1.51x10-5 mol L-1 (4.5 to 5000 ng mL-1), with an estimated detection limit of 4.84x10-8 -mol L-1 (1.5 ng mL-1). The proposed method offers, as competitive advantages comparing to the official method reported in the United States Pharmacopeia (USP 29), its simplicity, low cost and frequency of analysis, around 20 samples per hour

Analytical development for reverse-phase high resolution liquid chromatography for the simultaneous determination of propranolol hydrochloride, hydrochlorothiazide and chlorothiazide. Application of factorial design to the robustness of the method

ISSN-E: 2244-8845 PPI: 2012 02 ME 4102Un método por cromatografía líquida de alta resolución en fase reversa ha sido desarrollado para la determinación simultánea del clorhidrato de propranolol y la hidroclorotiazida, con detección de clorotiazida como impureza de síntesis. La separación se realizó en una columna X-BridgeTM C18 250 mm x 4,6 mm x 5 µm a 35 ºC. La fase móvil, con caudal de 1,0 mL min-1, quedó constituida por la solución A: solución amortiguadora de 0,1 M KH2PO4 y 0,05 M de 1-heptano sulfonato de sodio, a un pH 3,0 y un solvente B: acetonitrilo, aplicando un sistema de gradiente. La detección se realizó en un sistema de arreglo de diodos a 270 nm. La respuesta lineal se logró en un rango de concentración de 2,2 - 53,0 µg mL-1 para el clorhidrato de propranolol, de 1,4 - 34,0 µg mL-1 para la hidroclorotiazida y de 0,1 - 3,5 µg mL-1 para la clorotiazida. Un diseño factorial completo de 8 experimentos se aplicó para evaluar el nivel de influencia del pH, la [KH2PO4] y la [1-HSS] de la disolución amortiguadora, en la respuesta termodinámica del sistema para cada uno de los analitos en estudio. Un diseño factorial fraccionado de 8 experimentos fue empleado para estudiar la respuesta cinética del sistema con respecto a factores como: el solvente (% B), la temperatura, el flujo y el pH. Ambos diseños estadísticos mostraron resultados válidos sobre el margen razonable de fluctuación para cada factor y su interacción, que permitieron garantizar la robustez del método desarrollado con un 95% de [email protected]@[email protected]@ula.vesemestralA reverse-phase high performance liquid chromatographic method has been has been developed for the simultaneous determination of propranolol hydrochloride and hydrochlorothiazide, chlorothiazide sensing as an impurity of synthesis. The separation was performed on a C18 column X-BridgeTM 250 mm x 4.6 mm x 5 µm to 35 ºC. The mobile phase with flow rate of 1.0 mL min-1, was composed of solution A: 0.1 M buffer KH2PO4 and 0.05 M of 1-heptane sulfonate, pH 3.0 and solvent B: acetonitrile, using a gradient system. The detection was performed on a diode array system at 270 nm. The linear response was achieved in a concentration range of 2.2 to 53.0 µg mL-1 for propranolol hydrochloride, from 1.4 to 34.0 µg mL-1 for hydrochlorothiazide and 0.1 to 3.5 µg mL-1 for chlorothiazide. A full factorial design of 8 experiments was applied to assess the level of influence of pH, [KH2PO4] and [1-HSS] of the buffer solution, thermodynamics in the response of the system to each of the analytes under study. Fractional factorial design of 8 experiments was used to study the kinetic response of the system with respect to factors such as the solvent (% B), temperature, flow and pH. Both designs showed statistical valid results on reasonable margin of fluctuation for each factor and their interaction, which allowed guarantee the robustness of the method developed with 95 % confidence

Determinación simultánea de algunos elementos formadores de hidruros (Sb, Sn y Pb) en aleaciones de soldaduras blandas, mediante un sistema acoplado de Análisis en Flujo- Generación de Hidruros - Espectrometría Infrarroja de transformada de Fourier utilizando Regresión Lineal Múltiple

En el presente trabajo se propone la determinación simultánea de elementos formadores de hidruros (Sn, Sb y Pb) mediante un método basado en el acoplamiento de un sistema de análisis por inyección en flujo con generación de hidruros, utilizando la espectrometría infrarroja de transformada de Fourier como forma de detección y el algoritmo de Regresión Lineal Múltiple para la calibración de los analitos bajo estudio. Las características analíticas arrojadas por el sistema propuesto fueron adecuadas para la determinación de los hidruros en muestras de aleaciones utilizadas en soldaduras [email protected] this paper the simultaneous determination of hydride forming elements (Sn, Sb and Pb) is proposed by means of a method based on the coupling of a system of flow injection analysis with hydride generation, using infrared spectrometry Fourier transform as a means of detection and the Multiple Linear Regression algorithm for calibrating the analytes under study. The analytical characteristics thrown out by the proposed system were suitable for the determination of the hydrides in samples of alloys used in solders

Development and validation of a rapid column-switching high-performance liquid chromatographic method for the determination of atenolol, propranolol and carvedilol in human plasma

ISSN-E: 2244-8845 PPI: 2012 02 ME 4102En el presente trabajo se desarrolló un método automatizado y robusto para la determinación simultánea de atenolol, propranolol y carvedilol en muestras de plasma humano por cromatografía líquida de alta resolución (CLAR) con detección por fluorescencia. La inyección directa de las muestras de plasma se efectuó en una precolumna con empaque de acceso restringido LiChrospher RP-18 ADS (alquil diol sílica) integrada en un sistema de columnas acopladas bajo la modalidad de transferencia indirecta reversa. La separación cromatográfica de los analitos se realizó en una columna Altantis T3® (150 mm x 3,0 mm d.i. y 5 µm d.p.) y se utilizó la optimización multivariada para lograr la mejor resolución y tiempo de análisis. La validación del procedimiento se evaluó de acuerdo a la normativa vigente, la Farmacopea de los Estados Unidos (USP) y de la Conferencia Internacional de Armonización (ICH). El método propuesto se aplicó exitosamente en el análisis de muestras de plasma de individuos bajo tratamiento médico con los fármacos, con una frecuencia de análisis de 10 muestras [email protected]@[email protected]@[email protected] robust and automated high performance liquid chromatographic method has been developed and validated for the simultaneous determination of atenolol, propranolol and carvedilol in human plasma samples. The untreated plasma samples were directly injected onto restricted access LiChrospher RP-18 ADS (alquil diol sílica) precolumn into a column-switching system. Chromatographic separation of the analytes was performed on a T3 Altantis ® column (150 mm x 3.0 mm id and 5 microns dp) and multivariate optimization was used to achieve better resolution and analysis time. A full method validation was performed according to guidelines set by United States Pharmacopeia (USP) and the International Conference on Harmonization (ICH). The proposed method was successfully applied to analyze plasma samples from patients submitted to beta-blocker therapy, with a sampling frequency of 10 samples h-1