Using samples from the Total Diet Study, the average dietary intake per person of fluoride in the United Kingdom is estimated to be 1.82 mg day-1. Beverages account for 71 % of the total dietary intake and tea contributes most to the intake from the beverages group. Above-average consumption of tea, as recorded in Great Britain, could result in fluoride intakes as high as 8.9 mg day-1. It is estimated that tap water containing 1 mg litre-1 of fluoride could increase normal dietary intakes by 54%. Individual foods have been analysed and the results show that tea infusions and foods containing skin or bone have higher fluoride concentrations than other foods. Concentrations as high as 44 mg kg-1 were found in the tail meat of krill, and a sample of mechanically deboned meat contained 2.8 mg kg-1 fluoride. Samples of flour, bread, vegetables, meat and fish products and infant foods generally contained less than 1 me kg-1 of fluoride. Soft drinks from an area with a fluoridated water supply had a higher fluoride concentration than samples taken from an area with unfluoridated water.
A method is described for the determination of total chromium, cobalt and silver in foodstuffs. Organic matter is destroyed by a wet-digestion procedure and the cobalt and silver are concentrated by chelation with diethylammonium diethyldithiocarbamate and extraction into 4-methylpentan-2-one. Chromium is then chelated with pentane-2,4-dione and separately extracted into 4-methylpentan-2-one. The concentrations of the three elements in the extracts are measured by Aame atomic-absorption spectrophotometry. Keywords Chromium detevmination ; cobalt determination ; silver determinat i o n ; foodstufls analysis ; J a m e atomic-absorption spectrophotometry Chromium as chromium(II1) is a recognised essential element in human nutrition. Cobalt is said to be unique in that only one combined form, cyanocobalamin or vitamin B,,, is physiologically active in man.l No other functions for cobalt in the human diet have been clearly established, although dietary cobalt is utilised by ruminant animals. Silver appears t o have no known essential function in human physiology but is a possible contaminant of foodstuffs.Recently described methods for the trace analysis of chromium in various matrices include electrothermal atomic-absorption spectrophotometry following extractive concentration of sea water,, flame atomic-absorption spectrophotometry combined with direct extraction from hydrochloric acid s ~l u t i o n , ~ flame atomic-absorption spectrophotometry following extraction of the ammonium tetramethylene dithiocarbamate (ammonium pyrrolidine dithiocarbamate, APDC) complex or the pentane-2,4-dione (acetylacetone) complex for biological materials or sea gas-chromatographic methods for serum, and neutron-activation analysis for biological materials.* Methods used for trace analysis of cobalt are flame atomic-absorption spectrophotometry after APDC chelation and extraction for vegetables* and neutron-activation analysis for biological materialsg Procedures used hitherto for the trace analysis of silver include conventional atomic-absorption spectrophotometry,lo9l1 electrothermal Delves cup atomic-absorption spectrophotometry,12 plasma emission spectroscopy13 and neutron activation ana1y~is.l~ An estimate of the human intake, in the UK, of each element can be calculated from the results of the examination of the diets that constitute the UK total diet survey.15 Each diet consists of homogenates of nine classes of food, namely cereals, meat, fish, fats, sugars and preserves, root vegetables, green vegetables, beverages and milk from regions of the UK. A procedure was required for the measurement of levels of the three elements in each of these representative food groups.Figures for levels of silver in foodstuffs have rarely been reported. Method ReagentsSolutions should be prepared with distilled water.Williams Ultrar or an equivalent grade is recommended.All reagents should be of a suitable reagent grade, free from the elements being determined.
Quantification of recorded results must establish the integrity of individual results while at the same time ensuring that information derived from such results is not degraded. Daily dietary intake values have been calculated from arithmetic results obtained for ten diets of the UK total diet survey for six elements in three to five different ways. Quantifying arithmetic results from zero upwards in intervals defined by 68% confidence intervals has been shown to give comparable means for the homogenate groups of the ten diets with means obtained from the recorded arithmetic results for homogenate groups of the ten diets. Even when as many as 90% of the arithmetic results of an elemental survey are below the limit of detection of results for an element, the maximum difference in the derived daily dietary intake is 3% between that calculated from arithmetic results and that from results quantified by 68% confidence intervals. The best estimate for the intakes obtained for lithium, rubidium, strontium, molybdenum, vanadium and silver in this exercise are listed.
A method is described for the determination of cadmium, lead and nickel in foodstuffs. Organic matter is destroyed using a wet-digestion procedure and the three elements are concentrated by chelation with a mixture of ammonium tetramethylenedithiocarbamate and diethylammonium diethyldithiocarbamate and extraction from an acidic solution with 4-methylpentan-2-one ; measurement is by flame atomic-absorption spectrophotometry The accuracy of the method has been assessed, ionic interferences noted and standard deviations calculated both for the method itself and the method in application, for levels likely to be encountered in foodstuffs. C.onfidence intervals and detection limits have been deduced from the results obtained for each element, completing the qualification of the procedure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.