Medida del grado de insaturación de aceites y grasas comestibles por espectroscopia infrarroja y su relación con el índice de yodo

An spectroscopy method to fast determination of the degree of unsaturation of oils and fats is described by measurement of intensity of the olefinic band at 3007 cm-1 Using SNGLE program, the peak heigt and peak area and also 1st derivate and 2nd derivate at 3007 cm-1 are calculated and relationships between these parameters and iodine values are studied. The best relationships were obtained with the measurements of net absorbance (r=0,9992: error index=1,75%) and area (r=0,9992; error index= 1,77%).Se describe un método de espectroscopia IR para determinar de forma rápida el grado de insaturación de grasas y aceites comestibles, basado en la medida de la banda correspondiente al enlace olefínico a 3007 cm-1 Por medio del programa de análisis cuantitativo SNGLE se calcula la absorbancia neta, el área, la 1ª derivada y la 2ª derivada de la banda a 3007 cm-1 y se estudia la relación de estos parámetros con el índice de yodo. La mejor correlación y el menor índice de error se obtiene con las medidas de la absorbancia neta (r=0,9992; ind. error=1,75%) y el área (r=0,9992: ind. error=1,77%) de dicha banda

Algunos parámetros físico-químicos de la grasa del polen apícola

Refractive index, acid, saponification, ester, and iodine numbers were determinated in lipids from bee-collected pollen commercially purchased samples. Mean values are 1,4799 (1,4777-1,4825), 62 (48- 83), 142 (102-156), 80 (48-102) and 102 (108-134), respectively.Se determinan los índices de refracción, acidez, saponificación, éster e iodo de la grasa en 35 muestras de polen apícola manufacturadas obteniéndose unos valores promedios de 1,4799 (1,4777-1.4825), 62 (48-83), 142 (102-156), 80 (48-102) y 102 (108-134), respectivamente

Separación de las clases de lípidos neutros de polen apícola mediante cromatografía líquida de alta resolución (HPLC)

A fast method for the separation of neutral lipid classes of bee-collected pollen by isocratic HPLC is described using ultraviolet detection at 206 nm and direct injection of the sample into a silica column. The mobile phase was n-hexane-2-propanolacetic acid (100:0.5:0.1). Three fractions of neutral lipids were isolated from 35 samples: Sterol esters and other nonpolar compounds such as carotenoids and waxes; triglycerides; and fatty acids.Se describe un método rápido mediante HPLC para la separación de las diferentes clases de lípidos neutros del polen apícola en condiciones isocráticas, con detección UV a 206 nm e inyección directa de la muestra en columna de sílica. Como fase móvil se usa n-hexano-2-propanol-ácido acético (100:0,5:0,1). Se aislaron 3 fracciones de lípidos neutros en las 35 muestras analizadas: Esteres de esteroles y otros componentes no polares tales como carotenoides y ceras; triglicéridos y ácidos grasos

Phthalates, organotin compounds and per-polyfluoroalkyl substances in semiconfined areas of the Spanish coast: occurrence, sources and risk assessment

Postprint3,25

Occurrence of organotin compounds in waters of the spanish coast under the European Water Framework Directive

Organotin compounds (OTCs), such as tributyltin (TBT), are persistent organic pollutants that are present in water samples (surface water, river water, sea water, waste water, etc.) because of anthropogenic activities (antifouling agents in ship paints, biocides in polymers, etc.). The toxicity and endocrine disruption potential of these chemicals have been demonstrated even at very low levels (<1 ng L−1) (Devos et al. 2012). Due to the extensive presence of OTCs in all environmental media as well as their adverse effects on human health and biota, quantitative and qualitative determination of those com-pounds in complex environmental matrices has become a matter of great concern, mainly butyl and phenyl-substituted. Also, these compounds are included in the list of priority substances according to the EU Directive 2013/39/EU amending Directives 2000/60/EC and 2008/105/EC as regards priority substances in the field of water policy. This directive specifies annual average environmental quality standard (AA-EQS) of 0.2 ng L−1 TBT and a maximum allowable environmental quality standard (MAC-EQS) of 1.5 ng L−1 TBT for all surface waters. Samples were collected in two semiconfined coastal areas, one of them an area with high industrial and port activities (Ría de Vigo) and the other one with high touristic and agricultural activity (Mar Menor).The sampling campaigns were performed in spring and autumn of 2015. The levels of MBT, DBT, TBT, MPhT, DPhT and TPhT in the seawater samples were analyzed by HS-SPME-GC–QqQMS/ MS method (Moscoso-Pérez et al. 2015). MPhT, DPhT and TPhT were not detected in any sample at levels higher than LOQ. For butylated compounds, MBT, DBT and TBT were detected in 100% of the analyzed samples in the Mar Menor. In the Vigo estuary, MBT has been detected in 83.3% of the samples, the DBT in 75% and the TBT in 88%. The TBT is present in 92% of the total of 39 analyzed samples, being detected in 100% of the samples of the Mar Menor and in 88% of the samples of the Ría de Vigo. These levels are similar than those detected in other locations, and lower than the detected in ports near the coast of Gijón characterized by a great maritime traffic (Centineo et al. 2004).Program of Consolidation and Structuring of Units of Competitive Investigation of the University System of Galicia (Xunta de Galicia) potentially cofinanced by ERDF in the frame of the operative Program of Galicia 2007-2013 (reference: GRC2013-047) and by the Ministry of Economy and Competitiveness (IMPACTA, project reference: CTM2013-48194-C3-2-R, and ARPA-ACUA, project reference: CTM2016-77945-C3-3-R)