Pilar Bermejo - Academia.edu (original) (raw)

Papers by Pilar Bermejo

$Research paper thumbnail of Copper fractionation by SEC-HPLC and ETAAS: Study of breast milk and infant formulae whey used in lactation of full-term newborn infants$

The Analyst, 2001

This method will allow the determination of bound copper to low relative molecular mass compounds... more This method will allow the determination of bound copper to low relative molecular mass compounds in milk. The milk whey obtained by ultracentrifugation was submitted to fractionation by size exclusion chromatography (SEC) on a TSK-Gel2000 (Toso Haas) column with a mobile phase of 0.2 M NH 4 NO 3 + NH 3 , pH 6.7. Fractions of effluent corresponding to the protein peaks were collected and the copper content was determined by ETAAS. The method was sensitive (LOD 0.4 mg l 21 and LOQ 1.5 mg l 21 in the fraction; LOQ 7.5-22.5 mg l 21 referred to the milk sample and depended on fraction volume) and precise (RSD ± 10%). Media sample recoveries from the column were 101.2%. Cu was predominantly present in fractions corresponding to relative molecular mass 76 and 15 kDa of breast milk while copper was mostly found in fractions corresponding to 14 and 38 kDa of cow's milk-based infant formulae; moreover, copper was eluted in the relative molecular mass region < 6 kDa.

Journal of Trace Elements in Medicine and Biology, 2011

Introduction: Exposure to lead and cadmium is a public health problem due to the broad exposure t... more Introduction: Exposure to lead and cadmium is a public health problem due to the broad exposure to these toxic substances among the general population. The objective of this study is to determine blood lead and cadmium concentrations in a working population drawn from six university hospitals in Madrid, Getafe, Cartagena, Santiago de Compostela, Santander and Palma de Mallorca (Spain) and to identify associated factors. Materials and methods: 951 individuals participated in the study and were administered the standardized PESA ® questionnaire regarding exposure to lead and cadmium. The blood lead and cadmium concentrations were measured by electrothermal atomization atomic absorption spectrometry with Zeeman background correction in Perkin-Elmer spectrometers, guaranteeing the transferability of the results. Results: The median overall blood lead concentration was: 1.6 g/dL (IQR: 0.9-2.7) and that of cadmium was: 0.21 g/L (IQR: 0.10-0.50). There were significant differences in lead levels between men (2 g/dL) and women (1.5 g/dL), postmenopausal (2.6 g/dL) and premenopausal women (1.1 g/dL), and between participants who cooked in earthenware (2.1 g/dL) and those who did not (1.5 g/dL). The median of cadmium in women (0.24 g/L) was higher than in men (0.11 g/L) and was also higher in subjects who smoked (0.70 g/L) than in non-smokers (0.13 g/L). Conclusions: A reduction in blood lead and cadmium levels was observed with respect to previous studies carried out in Spain. Nevertheless, the results suggest there are certain factors which increase risk such as age, gender, menopause, age of housing, cooking in lead-glazed earthenware and exposure to cigarette smoke.

$Research paper thumbnail of Determination of selenium in infant formulas whey fractions by SEC�HPLC�HG�ETAAS$

Journal of Analytical Atomic Spectrometry, 2001

Page 1. Determination of selenium in infant formulas whey fractions by SEC-HPLC-HG-ETAAS{ Pilar B... more Page 1. Determination of selenium in infant formulas whey fractions by SEC-HPLC-HG-ETAAS{ Pilar Bermejo,*a Julia Barciela,a Elena M. PenÄa,a Adela Bermejo,a JoseÂ M. Fragab and JoseÂ A. Cochoc aDepartment of Analytical ...

International Dairy Journal, 2004

Five different iron salts-sulphate, lactate, diphosphate, encapsulated sulphate, and EDTA-Fe(III)... more Five different iron salts-sulphate, lactate, diphosphate, encapsulated sulphate, and EDTA-Fe(III)-were used to fortify an infant formula to study possible differences in iron bioavailability. The effect of iron fortification at two levels (0.5 mg Fe 100 kcal À1 and 1.5 mg Fe 100 kcal À1 ) on the bioavailability of other important trace elements such as copper and zinc were also evaluated. An in vitro method based on element dialysability (i.e., the fraction available by absorption) to simulate newborn digestion was applied to study iron, copper and zinc bioavailability. Enzyme treatment was carried out in two stages involving pepsin at pH 5.0 followed by pancreatin at pH 7.0. The incubation times were short to mimic the transit of meal in an infant's gastrointestinal tract. Iron, copper and zinc were determined using inductively coupled plasma atomic emission spectrometry using an axially configured device. The percentages of Fe, Cu and Zn dialysable at both iron fortification levels are discussed. From these results, EDTA-Fe (III) appears to be the most adequate salt for iron fortification of infant formulas. r

$Research paper thumbnail of Iron and zinc in hydrolised fractions of human milk and infant formulas using an in vitro method$

Food Chemistry, 2002

... In particular, these methods have been used to predict the availability from different foods ... more ... In particular, these methods have been used to predict the availability from different foods including milk or infant formulas ( Barbera; Cabrera; Crews; Crews; Deipenmaat; Garcia; Glahn; Jovani; Miller; Minihane; Roig; Shen; Shen and Shen) as a simple, rapid, inexpensive and ...

European Food Research and Technology, 2005

Fe, Cu and Zn determination by AAS was performed in 35 infant formula samples from different manu... more Fe, Cu and Zn determination by AAS was performed in 35 infant formula samples from different manufacturers. The trace element content was studied in whole, fat and whey milk, and different chemometric tools have been used in order to observe differences or correlations between infant formulas fortified with inorganic salts (iron, copper and zinc sulphates) or with organic and inorganic salts (iron and copper gluconates, or zinc and iron lactates and zinc oxides). Principal-components analysis (PCA) achieved a reduction from nine variables to three (accounting for 80.8% of the total variability), and some differences between infant formula from the two groups were observed.Cluster analysis gave similar results as PCA. Linear discriminant analysis (LDA) allowed the classification of infant formulas in two categories or classes: the first class formed by samples fortified with inorganic salts (category A) and the second one by samples fortified with organic and inorganic salts (category B). The percentages of samples correctly classified were 96.1 and 100.0 for the categories A and B, respectively. After the application of the soft independent modelling of class analogy (SIMCA) approach, percentages of cases correctly assigned of 87.5 and 12.5 were achieved for the categories A and B, respectively. However, it must be said that the application of SIMCA led to bad results because of the small number of sample used, mainly in category B.