H. López

Determination of total arsenic levels by hydride generation atomic absorption spectrometry in foods from south-east Spain: estimation of daily dietary intake

The total concentration of arsenic in different foods from south-east Spain was determined by hydride generation atomic absorption spectrometry. Mineralization was carried out with an HNO3-HClO4 mixture in a thermostated sand bath. Arsenic determination was performed by the standard addition method. Analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of the technique. The highest arsenic levels were found in seafood, cereals, meat and meat by-products. In meat and meat by-products, the total arsenic measured in meat was significantly higher than that in sausages (p<0.05). In cereals, arsenic concentrations in corn and white rice samples were significantly higher (p<0.01) than those measured in wheat by-products. Mean arsenic concentrations in cheese were statistically lower than those in other dairy products (p<0.01). New data have been provided on the total arsenic content of a variety of foods in Spain, which is important for making exposure estimates. The estimated daily intake of total arsenic in the Spanish diet was 221 μg As day−1.

Microwave dissolution for the determination of mercury in fish by cold vapour atomic absorption spectrometry

Abstract A procedure is described for the determination in fish species from the Mediterranean Spanish coast by cold vapour atomic absorption spectrometry. The samples were decomposed with nitric acid in a microwave acid digestion bomb. A certified reference sample was analysed and the results obtained agreed well with the certified values. The limit of detection for the samples investigated was 0.195 ng ml −1 . The concentrations of mercury in fish ranged from 0.033 to 1.211 μg g −1 .

Zinc levels in foods from southeastern Spain: relationship to daily dietary intake

The zinc content of 300 food and 79 beverage samples was determined using flame atomic absorption spectrometry. Sample recoveries, repeatability, and analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of this technique. Mean zinc concentrations varied from 0.02 μg/ml in fresh water to 71.0 μg/g (fresh weight) in pork liver. The daily dietary intake of zinc for inhabitants of southeastern Spain was estimated to be 10.1 mg (5.5, 4.0, 0.5, and 0.1 mg Zn/day per person from foods of animal and vegetable origin, drinks, and other foods, respectively). Zinc levels found in high protein foods (meat, fish, milk products, eggs, dry fruits, cereals and legumes) were significantly higher than those found in food with a low protein content (vegetables, fruits and drinks) (p < 0.001). A significant linear correlation between zinc levels and the corresponding protein content of cereals, legumes and dry fruits was found (r = 0.754, p < 0.005). Zinc concentrations in milk samples were significanlty modified by the thermal treatment (p < 0.001), and the skimming (p < 0.05) and calcium enrichment processes (p < 0.001). Shellfish zinc levels were also significantly higher than those measured in fish (p < 0.05). Mean zinc concentrations found in cheese were statistically higher than those determined in the remaining milk products (p < 0.001). Zinc levels measured in distilled beverages were also statistically lower than those found in fermented ones (p < 0.001).

The effect of industrial pollution on mercury levels in water, soil, and sludge in the coastal area of Motril, Southeast Spain

The total concentration of mercury was determined in samples of water, soil and sludge from the Mediterranean coastal area of Southeast Spain (Motril), where Hg contamination is produced primarily by a local paper mill. Samples were taken at surface level in a 5 Km radius from the factory. The total Hg concentrations varied from 0.117 to 0.760 μg/g in soil and sludge, and from ND to 2.088 μg/L in water. A negative correlation was observed between the distance of the sampling station from the mill and the concentration of Hg in the soil and sludge samples. Similarly, an increase in Hg concentration was observed in the freshwater and wastewater after passing close to the factory.

Copper, zinc, calcium and magnesium content of alcoholic beverages and by-products from Spain: Nutritional supply

Levels of copper, zinc, calcium and magnesium were measured in alcoholic beverages (whiskies, gins, rums, liquors, brandies, wines and beers) and by-products (non-alcoholic liquors and vinegars) using flame atomic absorption spectrometry (FAAS). Mineral concentrations were found to be significantly different between the nine alcoholic and non-alcoholic by-products studied (p < 0.001). In distilled alcoholic beverages, concentrations measured in rums and brandies were statistically lower than those determined in gins and alcoholic liquors (p = 0.001). For Cu, measured concentrations were statistically different for each of the five groups of distilled alcoholic beverages studied (p < 0.001). In fermented beverages, Zn, Ca and Mg levels were significantly higher than those concentrations determined in distilled drinks (p < 0.005). Contrarily, Cu concentrations were statistically lower (p < 0.001). Wines designated as sherry had significantly higher Ca and Mg levels (p < 0.005). White wines had significantly higher Ca and Zn levels (p < 0.05) compared with red wines and, contrarily, Cu concentrations were significantly lower (p < 0.005). In wine samples and corresponding by-products (brandy and vinegar), statistical differences were established for all minerals analysed (p < 0.01). Remarkably, for Cu, the concentrations determined in brandies were statistically higher. On the basis of element levels and the official data on consumption of alcoholic beverages and by-products in Spain, their contribution to the daily dietary intake (DDI) was calculated to be 124.6 µg Cu day−1 and 193.3 µg Zn day−1, 40.3 mg Ca day−1 and 19.9 mg Mg day−1. From all studied elements, Cu was the one for which alcoholic beverages constitute a significant source (more than 10% of recommended daily intake). These findings are of potential use to food composition tables.

Serum selenium levels during normal pregnancy in healthy Spanish women.

In this study, we determined selenium concentrations in serum samples of healthy women (146 pregnant and 74 nonpregnant) living in the Mediterranean area of the coast of Granada (southeast Spain). The subjects were distributed in two groups: group A (pregnant women), divided into three categories according to the trimester of pregnancy, and group B (nonpregnant women). No significant differences were observed in the selenium levels either among pregnant women according to the trimester of pregnancy or in the group of nonpregnant women. No other significant differences were determined as regards the age of pregnant women (P > 0.05). Serum selenium levels are slightly lower during pregnancy. Considering that serum selenium levels affect the body selenium status, the concentrations determined establish the non-existence of selenium problems in the daily dietary intake with respect to maternal and fetal necessities during pregnancy.

High Performance Liquid Chromatography Determination of Furanic Compounds in Commercial Brandies and Caramels

Abstract A technique using high performance liquid chromatography to determine the furanic aldehydes: furfural and 5-hidroxymethil furfural, in aged brandies and hydroalcoholic solutions of commercial caramels, was developed. Separation and quantification of these substances can be carried out by injecting the samples directly into the chromatograph, the relative error presented under this method is 0.52% for furfural and 0.29% for 5-HMF. The high concentrations of 5-hidroxymethil furfural found in 100% of the brandy samples analysed is due to the caramel added as a colouring agent.

Determination of selenium levels in dairy products and drinks by hydride generation atomic absorption spectrometry: correlation with daily dietary intake.

The selenium concentrations in different dairy products and drinks in the Mediterranean coastal area of southeastern Spain have been determined by hydride generation atomic absorption spectrometry. Mineralization was carried out with an HNO3-HClO4 mixture (4:1) in a thermostatted sand bath. Selenium determination was carried out by the standard addition method. Mean concentrations obtained in diary products varied from 6.87 ng/g (rice pudding) to 178.90 ng/g (caramel custard), and those in drinks from 0.256 micrograms/l (wine) to 2.879 micrograms/l (pineapple juice). Repeatability, expressed as relative standard deviation, ranged from 5.06% to 13.25%. The results obtained from the recovery studies were proximate to 100%. Considering the mean daily individual consumption of these foods in Andalusia (southern Spain), the daily dietary intake of selenium supplied by this source is 5.869 micrograms per person per day.

Selenium (IV) and (VI) levels in potable, irrigation and waste waters from an industrial zone in southeastern Spain

Selenium in potable, irrigation and waster waters was chemically specified in 62 stations of an industrial zone in southeastern Spain. Hydride generation atomic absorption spectrometry was the method for direct analysis of Se (IV). Prior reduction to Se (IV) by means of HCLoc was necessary for measurement of Se (VI). Se (IV) and Se (VI) concentrations ranged respectively from not detectable to 0.380 μg/l and from not detectable to 0.280 μg/l. There are no significant differences between the levels of Se (IV) or Se (VI) in the three types of water (P > 0.01). Total Se levels, Se (IV) and Se (VI) of the water in the zone are not affected by human and industrial activity. The low concentrations determined show a low selenium content in those soils through which the water of the zone is leached and drained. Se (IV) concentrations in water are low, but slightly higher than those of Se (VI); for this reason the soluble, bioavailable fraction (mainly present as SeO42−) for the crops in the zone is also low. The daily dietary intake of selenium supplied by drinking water is < 0.5 μg per person.

The Influence of Oak on the Furanic Aldehyde Contents of Distillates Subjected to Aging

Abstract The furfural and 5-hydroximethyl furfural content was analyzed by H. P. L. C. in distilled alcoholic beverages subjected to different periods of aging in barrels of French Limousin and American Kentucky oak. The presence of these furanic compounds is not due to the length of time spent in the barrel. The age of the barrel, its manner of use and the charring process control the concentration of furanic aldehydes.