Determination of Trace Elements in Foods by HCl-HNO3 Leaching and Flame Atomic Absorption Spectroscopy

Abstract

Aluminum, iron, tin, zinc, calcium, magnesium, nickel, copper, chromium, cadmium, and potassium in foods can be extracted by HC1- HN03 leaching and determined quantitatively using flame atomic absorption spectroscopy (AAS), with recoveries ranging from 90 to 110%. Thirty to 40 samples of almost any type of food sample can be analyzed routinely for 2 elements in 4-5 h. In contrast, one or 2 days are required when a wet-ash or dry-ash technique is used. Extraction consists of weighing 2-10 g samples into 125 mL Erlenmeyer flasks, adding 20 mL concentrated HCI-HNO3 (9 + 1), then heating in a 82- 93°C water bath for 30 min. After cooling, samples are diluted to volume in 50 mL Nessler tubes and then filtered through No. 541 or 540 Whatman paper. The filtrate is analyzed directly by AAS.

Qualitative and quantitative 1H NMR spectroscopy for determination of divalent metal cation concentration in model salt solutions, food supplements, and pharmaceutical products by using EDTA as chelating agent

“…Because titration is sensitive to several parameters such as pH and temperature, these values usually need to be monitored and controlled continuously. In more recent decades, additional methods have been developed for flame atomic absorption spectrometry , ion chromatography, and inductively coupled plasma atomic absorption or mass spectrometry . These techniques are advantageous due to their sensitivity, reliability, and accuracy.…”

Determination of Vanadium in Foods by Atomic Absorption Spectrometry

“…Food samples were digested according to a previously described procedure (28). Briefly, 10g of the homogenised samples was weighed into 250 ml Erlenmeyer flask and 20 ml of the acid mixture (HCl-HNO 3 ; 9 + 1) added.…”