Determination of zinc levels in waters from southeastern Spain by electrothermal atomic absorption spectrometry: relationship with industrial activity.

An efficient method for the determination of nanogram levels of zinc in waters (potable, irrigation, waste and sea waters) is described. Acidified water samples were analyzed by an accurately optimized time/temperature program for electrothermal atomic absorption spectrometry. The samples were previously treated with a matrix modifier consisting of 0.1% Mg(NO3)2 in 0.5 M HNO3 and injected through a graphite tube with L'Vov platform. Sample recoveries, repeteability, and analyses of NIST reference material demonstrated the reliability and accuracy of this technique. Zinc concentrations ranged from 2.0 to 73.0 microg l(-1). No significant differences among the mean zinc levels determined in the four types of water considered from southeastern Spain were found. Zinc concentrations in waters from the zone were not affected by human and industrial activity.

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 microg/ml in fresh water to 71.0 microg/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 significantly 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).

Application of chemometric techniques in obtaining macerates with phenolic compound content similar to that of wines from the Jerez-Shery region subjected to oxidative aging.

This paper studies and quantifies the final concentration of phenolic aldehydes and acids (determined by HPLC) in a series of sobretablas wine macerates prepared with American oak shavings subjected to an accelerated aging system developed by our research group and based on thermal processes traditionally used in cooperage. This experiment aims to considerably reduce and control the oxidative aging period of oloroso wines from the Jerez-Sherry region as occurs in the dynamic system of soleras and criaderas, with the consequent economic benefits. To standardize the process by controlling the production technique of the macerates, the results were subjected to surface response methodology as a means of optimizing the experiment. The proposed model was found to be suitable after evaluation of the factors affecting the final concentration. Of the factors studied, it was found to be essential to control the charring time and/or the interactions between temperature and charring time for 10 of the 11 phenolic compounds studied.

Serum zinc and copper concentrations and Cu/Zn ratios in patients with hepatopathies or diabetes.

The serum zinc and copper levels, as well as Zn/Cu ratios, were determined in 30 patients (18 with diabetes and 12 with hepatopathies) and compared to healthy-age matched controls by atomic absorption spectrometry. Serum Zn (0.946 +/- 0.302 mg/l) and Cu (0.952 +/- 0.355 mg/l) concentrations were not significantly different in patients with hepatopathies as compared to controls (p > 0.05). Serum Zn concentrations (0.778 +/- 0.164 mg/l) were significantly lower in diabetic patients than those determined in controls (p < 0.01). In contrast, Cu levels (0.987 +/- 0.305 mg/l) were not significantly different (p > 0.05) than in controls. Serum Cu/Zn ratios were not significantly different in patients with diabetes or hepatopathies than those measured in healthy controls (p > 0.05). In patients, no statistically significant differences were observed in the Zn, Cu and Cu/Zn with respect to sex (p > 0.05) or age (p > 0.05).

Serum zinc levels in healthy subjects from southeastern Spain.

The serum zinc (Zn) concentrations of 80 healthy subjects (48 male, 32 female) from southeastern Spain were determined by atomic absorption spectrometry. The samples were digested by heating in a 4:1 mixture of nitric and perchloric acids. The concentration of Zn was determined against a Contox Trace Metal Serum Control Panel A standard reference. Zn concentrations in the standard were found to be 2.332+/-0.489 mg/L, with a mean recovery of 102.7%. In the serum samples, the relative standard deviation was <6% for the range of concentrations determined: 0.420-1.540 mg/L for women (mean value 0.947+/-0.265 mg/L) and 0.490-1.480 mg/L for men (mean value 0.951+/-0.243 mg/L). In healthy subjects, no statistically significant differences were observed in the Zn levels with respect to their sex (p > 0.05) or the location where they lived (mountainous vs coastal zones). It is concluded that the dietary Zn intake and Zn status for healthy adults in this region of Spain are within normal values.

Zinc and copper concentrations in serum from Spanish women during pregnancy.

A cross-sectional study of serum zinc (Zn) and copper (Cu) levels in 31 healthy pregnant women and 51 healthy, nonpregnant controls living in the Mediterranean area of Granada, Spain, was performed. The subjects were divided into two groups: Group A, consisted of pregnant women in three categories according to the trimester of pregnancy, and Group B consisted of nonpregnant women acting as controls. In pregnant women, serum Zn levels were found from 0.300-1.340 mg/L and serum Cu from 0.936-2.304 mg/L, whereas in the nonpregnant women group, the mean serum levels were 0.947+/-0.265 mg/L for Zn and 1.092+/-0.365 mg/L for Cu. Serum Zn progressively decreased with gestation. Mean Zn levels were 0.829+/-0.253, 0.846+/-0.329, and 0.620+/-0.142 mg/L, corresponding to the first, second, and third trimesters of pregnancy, respectively. Serum Zn concentrations were significantly lower in pregnant women as compared to controls: 0.712+/-0.236 mg/L vs 0.947+/-0.265 mg/L, respectively (p < 0.05). In contrast, Cu levels increased with period of gestation from 1.053+/-0.498 mg/L in the first trimester to 1.616+/-0.304 mg/L in the second and 1.689+/-0.344 mg/L in the third. Serum Cu levels in the second and third trimesters of pregnancy were significantly higher (p < 0.05) than those determined during the first trimester and for nonpregnant controls. Both Zn and Cu during pregnancy did not appear to be dependent on the subject's age (p > 0.05).

Serum copper and zinc concentrations in serum from patients with cancer and cardiovascular disease.

A single cross-sectional study for serum copper and zinc levels was evaluated in 20 patients with cancer (respiratory, digestive, haematological, gynaecological) and 21 patients with cardiopathy (acute myocardial infarction and ischemic cardiomyopathy). A control group of 84 healthy subjects was selected. The mean serum zinc levels in patients with gynaecological cancer and ischemic cardiomyopathy were significantly lower than the control group (P < 0.05). However, the mean serum copper level was not statistically different among patients with cancer (P < 0.05) and cardiomyopathy (P > 0.05) than the control group. Male patients did not have statistically different values for serum Cu (P > 0.05) and Zn (P < 0.05) than those found in female patients. Patients' age did not have any statistical influence (P > 0.05) on serum Cu and Zn levels.

Determination of copper levels in serum of healthy subjects by atomic absorption spectrometry.

Copper levels in serum samples of 84 healthy subjects living in southeastern Spain were determined using the flame atomic absorption spectrometry technique. Mineralization of samples was carried out with an HNO3/HClO4 (4:1) mixture in a thermostated mineralization block. The accuracy of the method was tested by using a standard reference material. A mean recovery percentage of 104.70% was obtained. The relative standard deviation (R.S.D.) as a measurement of the precision of the method was lower than 5% in the concentration range considered. Mean copper concentrations were 1.092 +/- 0.365 mg/l (with the range 0.304-2.000 mg/l) and 1.113 +/- 0.253 mg/l (corresponding to an interval of 0.648-1.760 mg/l) for women and men, respectively. There are no significant differences between the copper levels in serum according to either sex or geography zone (P > 0.05). For example, there were no differences of copper levels in serum of subjects from coastal and mountainous zones. Estimated daily dietary intakes on copper in women and men were 1.38 and 2.10 mg Cu/day respectively.