Direct determination of calcium, magnesium, sodium, potassium and iron in infant formulas by atomic spectroscopy. Comparison with dry and wet digestions methods

Abstract

SummaryAn optimization and comparison of three atomic absorption spectroscopic methods for measuring Ca, Mg, Na, K and Fe contents of infant formulas are carried out. The first method is a direct measure of a sample dispersion in water. The second method involves a previous wet digestion (HNO, + H,OJ in a microwave oven. And finally a dry mineralization at 450 "C is assayed. In order to measure Ca and Mg lanthanum at 0.4% concentration and in the case of Na and K cesium at 0.1 % were added.The analytical parameters of the three methods assayed were determined. Results obtained show that the three studied methods are accurdce and reliable and no significant difference among them at a probability level of 99% were found.Given the fact that the direct measure of the dispersed sample is the most simple and costless, it could be recommended to measure Ca, Mg, Na, K and Fe in infant formulas. ZusammenfassungDirektbestimmung von Calcium, Magnesium, Natrium, Kalium und Eisen in Babynahrung mittels Atomspektroskopie. Vergleich von Trocken-und NaDaufschluBverfahren Drei atomspektroskopische Bestimmungsverfahren fur Calcium, Magnesium, Natrium, Kalium und Eisen in Sauglingsfertignahrung wurden optimiert und verglichen. Die erste Methode ist eine direkte Bestimmung der Zielelemente nach Auflosung der Probe in Wasser. Die zweite Methode setzt einen vorherigen NaljaufschluR (HNO, + H,Oz) der Probe im Mikrowellenofen voraus. Bei der dritten Methode wird die organische Materie auf trockenem Weg bei 450 "C zerstort. Fur die Calcium-und Magnesiummessung wird Lanthan bis zu einer Endkonzentration von 0,4% zugegeben und fur die Natrium-und Kaliumbestimmung Caesium in 0,l %iger Konzentration.Die analytischen Parameter der drei untersuchten Verfdhren werden bestimmt. Die Ergebnisse zeigen, daR die drei Methoden ausreichend prazise und exakt sind und dalj bei einem Wahrscheinlichkeitsniveau von 99% keine signifikanten Unterschiede bestehen. Als Routineverfahren fur die Bestimmung der Zielelemente Ca, Mg, Na, K und Fe in Sauglingsfertignahrung wird die Direktbestimmung nach vorangegangener Dispersion der Probe in Wasser und anschlieknder Messung durch Atomabsorptionsspektroskopie vorgeschlagen. Diese Methode ist die einfachste und benotigt den geringsten materiellen und zeitlichen Aufwand.

Kinetics of ascorbic acid degradation in fruit-based infant foods during storage

“…Ashes: dry mineralization (450°C/24 h) (Ruiz et al, 1995 (AOAC, 2000). Fat: Gravimetrically after extraction according to Folch et al (1957) modified by Boselli et al (2001).…”

“…Fat: Gravimetrically after extraction according to Folch et al (1957) modified by Boselli et al (2001). Iron, zinc and sodium: Flame atomic absorption spectrophotometry upon white dry ashes and dissolution of the latter with hydrochloric acid (in the case of iron and zinc) or nitric acid (sodium) (Ruiz et al, 1995).…”

Determination of inorganic elements in milk powder using wavelength dispersive X‐ray fluorescence spectrometer

“…Determination of the inorganic elements in food materials, using a variety of analytical techniques, has been reported (Ihnat 2003). Atomic absorption spectrophotometry (Ruiz et al. 1995; Mendil 2006; Noel et al.…”

“…Determination of the inorganic elements in food materials, using a variety of analytical techniques, has been reported (Ihnat 2003). Atomic absorption spectrophotometry (Ruiz et al 1995;Mendil 2006;Noel et al 2008), inductively coupled plasma-optical emission spectrometry (Kira and Maihara 2007) and inductively coupled plasma-mass spectrometry (Martino et al 2001) are widely used for trace element analysis in food. The spectroscopic techniques and imaging methods used for solving problems in dairy science have been extensively discussed (Dufour 2011), and FTIR technique has been used to determine cholesterol in dairy products (Paradkar and Irudayaraj 2002).…”

Nutritional Metals in Foods by AAS

“…Essential and trace mineral content in a number of tomato fruit cultivars was determined by (Ruiz et al 1995) Their work is reported here under the section on vegetables as in Australia and some other countries, tomatoes are regarded as a vegetable. Essential minerals studied were calcium, magnesium, potassium and sodium while the trace metals were copper, iron, manganese and zinc.…”