Comparison of two methods using atomic absorption spectrometry for determination of selenium in food.

This study describes and compares two methods of atomic absorption spectrometry (AAS) for the selenium (Se) analysis in food: electrothermal AAS (ET AAS) and hydride generation method of AAS (HG AAS). The accuracy of the two methods was established by analysing two biological reference materials: Wheat Flour 1567a and Bovine Liver 1577b from the National Institute of Standards and Technology, USA. Good agreement with certified values was obtained for both methods. The accuracy of ET AAS method is 109% and 103% for Wheat Flour and Bovine Liver, respectively. The respective accuracies for HG AAS method were 88% and 87%. The detection limit obtained for ET AAS was 1 microgram Se/L and for HG AAS 0.02 microgram Se/L. The repeatability of ET AAS method was 5-11% and that of HG AAS 14-17%. Both methods are similar in accuracy and repeatability, but hydride generation (HG AAS) is more sensitive than graphite furnace technique (ET AAS) for determination of selenium in food.

Daily dietary intake of selenium in eastern Croatia.

Data on the selenium content in the soil and human milk in eastern Croatia indicate a possibility of inadequate Se status of people in the area. In order to determine the daily dietary intake of Se in eastern Croatia, a 7-day duplicate diet study was performed. There were 41 participants (18-53 years old; 14 males and 27 females). Selenium measurement was carried out in a HG-AAS. The average daily Se intake in the area is 27.3 micrograms. A significant difference (P < 0.05) exists between male (32.2 micrograms) and female (24.8 micrograms) participants. Percentage of optimum Se intake shows an inverse association with the increasing age of subjects (r = 0.43; P < 0.01). Relationship between Se intake and intakes of different foods (cereal products, milk and dairy products, meat, fish, etc.) was also examined. The sub-optimal Se intake (RDA is 55 micrograms/day for women and 70 micrograms/day for men) is a reflection of low Se levels in the environment, so supplementation of fertilizers with Se should be considered.

[Chrome, nickel and manganese in stainless steel cooking utensils and legal regulations]. / Krom, nikal i mangan u posudu od nehrdajuceg celika i zakonski propisi.

Assaying chromium nickel and manganese for specific migrations with a 4%-acetic acid under specific time and temperature related conditions is an obligatory part of the hygienic safety surveillance. Routine surveillance of a larger number of imported cooking utensils has shown the specific migrations to be more or less above the maximum allowances for chromium and/or nickel, and less frequently so for manganese. Further tests with repeated extraction, however, revealed that the levels of all three metals in most of the unfit samples were within the allowed limits. With respect to our findings, and to a longer period of use of the cooking utensils, amendments to the current regulations demanding obligatory testing after repeated extraction seem justified.

Copper and zinc content in human milk in Croatia.

The aim of this paper was to research whether there had been any statistically significant difference in the content of Cu and Zn in human milk depending on the social status of women (refugee and non-refugee), age, number of deliveries, days after delivery, weight gained by nursing women and smoking habits, as well as whether the infants had received sufficient quantities of these elements. The elements were determined by flame atomic absorption spectrometry. The samples were collected in the Clinical Hospital Osijek and Refugee Centre Nabrde, near Osijek, Eastern Croatia. The Cu in human milk ranged from 0.27 mg/l to 1.35 mg/l, and Zn from 0.62 mg/l to 15.0 mg/l. The mean levels of Cu and Zn for each group, formed according to the results of the questionnaire are presented too. Calculated daily dietary intake of these elements accords with the RDA.

Aluminum levels in human milk.

Aluminium levels in human milk in the winter period of 1992/93 ranged from 0.004 mg/l to 2.67 mg/l and the mean value was 0.38 mg/l. The nursing women were divided into several groups according to the results of a questionnaire, i.e. according to their social status (if they were refugees or not), number of deliveries, post partum day, the weight they put on during pregnancy, their age, and smoking habits. The mean levels of aluminium for each group were presented. The measurement of aluminium was done by graphite furnace atomic absorption spectrophotometry.

Selenium content of breast milk.

Selenium levels in human milk in the winter period ranged from 5.3 micrograms/l to 23.8 micrograms/l, the mean value being 11.0 micrograms/l. The nursing women were divided into several groups according to the results of a questionnaire, i.e. according to their social status (refugees or otherwise), number of deliveries, post partum days, the weight they had gained during pregnancy, their age and smoking habits. The mean levels of selenium for each group are presented. Selenium was determined by hydride generation atomic absorption spectrometry.

Aluminium content of soft drinks from aluminium cans.

The aluminium (Al) content of soft drinks from Al cans has been measured during 12 months of storage, by the graphite furnace atomic absorption spectrophotometry (GFAAS) method. The results show that the Al content in all soft drinks increased during the whole storage time. This increase was a result of dissolution of Al from the can wall due to the presence of aggressive ingredients in the soft drinks, mainly acids. The Al content rose with increasing acid concentration and decreasing pH value of the soft drinks. The evaluated possible daily intake of Al (0.8 mg) through consumption of these drinks was practically negligible in relation to total daily dietary Al intake, as well as to tolerable daily intake. Thus, soft drinks from Al cans are an insignificant source of dietary Al intake and it appears that the Al intake from this source should not be a cause for concern in regard to Al toxicity for the human body.

Ash and chromium levels of some types of honey.

The effect of season and species of plant on the ash and chromium (Cr) content of honey was studied. There were four types of honey: sunflower, acacia, floral and wild floral. In total there were 80 samples. The botanical origin of the honey was determined by microscopic analyses of pollen as well as the organoleptic properties. The Cr content was measured by flame atomic absorption spectrophotometry. The average Cr content in two consecutive seasons for all species was 0.121 microgram/g wet weight, and 0.1515 microgram/g dry weight. For sunflower, acacia, floral and wild floral honey the mean values were 0.103 microgram/g, 0.152 microgram/g, 0.125 microgram/g and 0.098 microgram/g wet weight and 0.1305 microgram/g, 0.1883 microgram/g, 0.1603 microgram/g and 0.1206 microgram/g dry weight, respectively. The average ash content in all 80 samples was 0.141%. There was a statistically significant (P < 0.05) influence of season on the ash content as well as interaction of species and season on the Cr content.