Observations on the determination of total copper, iron, manganese and zinc in foodstuffs by flame atomic-absorption spectrophotometry

Abstract

A method is described for the determination of total copper, iron, manganese and zinc in foodstuffs. Organic matter is destroyed by wet oxidation and measurement is made directly upon the sulphuric acid digests by flame atomic-absorption spectrophotometry . In the measurement, direct interferences from the inorganic species found in foodstuffs are shown to be a function of burner design and usage. Elimination of these interferences may be achieved for optimum conditions of use, thereby avoiding systematic bias. Isolation of the sources of variation during measurement reveals indirect interferences that enhance the standard deviation of measurement, despite individual presentation of solutions. The accuracy of the method in application to foodstuffs is assessed+for the levels of each element normally present. The standard deviations of results are compared with those for measurement alone and the further influence of indirect interferences on the former is inferred. Derived confidence intervals and limits of detection are given for each element.

Ascorbic Acid and Element Contents of Foods of Trabzon (Turkey)

“…Determinations of Fe, Cu, and Zn have been done by flame atomic absorption spectrophotometric method (Demir et al, 1990;Evans et al, 1980;Heanes, 1981;Crosby, 1977;Robles and Lachica, 1971;Nielson et al, 1988) in which sample solutions were aspirated directly into flame. The instrument's linearity was determined as to 5 ppm for Fe and Cu and to 1 ppm for Zn.…”

Microwave Digestion of Multi‐Component Foods for Sodium Analysis by Atomic Absorption Spectrometry

“…Specific-ion methods have also been used for determination of sodium in processed meat products (Fulton, et al, 1984) and meat (Averill, 1983). Dry ashing (Heanes, 1981), wet ashing (Arafat and Glooschenko, 1981;Evans et al, 1980), or combination of dry and wet ashing (Hill et al, 1986) have been used for sample digestion for mineral determination. Ashing times may require time from a few hours to days.…”

Digestion of biological materials for mineral analyses using a combination of wet and dry ashing

“…Some common procedures for digestion are low-temperature dry ashing in an oxygen plasma (2)(3)(4)(5)(6), high-temperature dry ashing (6)(7)(8)(9)(10)(11)(12)(13), and low-temperature wet ashing in an acid solution (13)(14)(15)(16)(17)(18)(19). None of these methods is without problems.…”