scholarly journals Determination of Metals in Foods by Atomic Absorption Spectrometry after Dry Ashing: NMKL1 Collaborative Study

2000 ◽  
Vol 83 (5) ◽  
pp. 1204-1211 ◽  
Author(s):  
Lars Jorhem ◽  
G Afthan ◽  
G Cumont ◽  
H P Dypdahl ◽  
K Gadd ◽  
...  

Abstract A method for determination of lead, cadmium, zinc, copper, and iron in foods by atomic absorption spectrometry (AAS) after dry ashing at 450°C was collaboratively studied in 16 laboratories. The study was preceded by a practice round of familiarization samples and another round in which solutions were distributed and the metals were determined directly by AAS. The study included 5 different foods (liver paste, apple sauce, minced fish, wheat bran, and milk powder) and 2 simulated diets. A single analysis was carried out with each sample. Suitable sample combinations were used as split-level combinations for determination of the repeatability standard deviation. The reproducibility relative standard deviation for each of the elements ranged from 20 to 50% for lead concentrations of 0.040–0.25 mg/kg, from 12 to 352% for cadmium concentrations of 0.001–0.51 mg/kg, from 4 to 8% for zinc concentrations of 0.7–38 mg/kg, from 7 to 45% for copper concentrations of 0.51–45 mg /kg, and from 11 to 14% for iron concentrations of 4–216 mg/kg.

2000 ◽  
Vol 83 (5) ◽  
pp. 1189-1203 ◽  
Author(s):  
Lars Jorhem ◽  
Joakim Engman ◽  
B-M Arvidsson ◽  
B Åsman ◽  
C Åstrand ◽  
...  

Abstract A method for determination of lead, cadmium, zinc, copper, and iron by atomic absorption spectrometry (AAS) after microwave digestion was subjected to a collaborative study in which 16 laboratories participated [including users of inductively coupled plasma (ICP) and ICP–mass spectrometry (MS)]. The types of samples included in the study were minced fish, wheat bran, milk powder, bovine and pig liver, mushroom, 2 simulated diets, and bovine muscle; the last 4 were certified reference materials. These were analyzed as single (4 samples), double blind (1 sample), or split level (2 samples) samples. Before the collaborative study, a pretrial was conducted in which 4 ready-made solutions and one fish tissue sample were analyzed for Pb and Cu. The reproducibility relative standard deviation (RSDR) values, for results above the detection limit, ranged from 59% at 0.155 mg/kg to 16% at 1.62 mg/kg for Pb, from 28% at 0.0124 mg/kg to 11% at 0.482 mg/kg for Cd, from 9.3% at 35.3 mg/kg to 1.7% at 147 mg/kg for Zn, from 39% at 0.241 mg/kg to 3.0% at 63.4 mg/kg for Cu, and from 17% at 7.4 mg/kg to 5.9% at 303 mg/kg for Fe. The RSDR values agreed well with the norms described by the International Union of Pure and Applied Chemistry. As a complement to the AAS determinations, a number of laboratories analyzed the samples either by ICP or by ICP–MS. The results of these analyses agreed well with the AAS results. On the basis of the results of the collaborative study, the method was adopted Official First Action by AOAC INTERNATIONAL.


2005 ◽  
Vol 88 (4) ◽  
pp. 1242-1246 ◽  
Author(s):  
Marcos M Kaplan ◽  
Soledad Cerutti ◽  
José A Salonia ◽  
José A Gásquez ◽  
Luis D Martinez

Abstract A procedure for the determination of traces of total tellurium (Te) in garlic (Allium sativa) is described that combines hydride generation atomic absorption spectrometry with preconcentration of the analyte by coprecipitation. The samples, each spiked with lanthanum nitrate (20 mg/L), are introduced into an Amberlite XAD-4 resin and mixed with ammonium buffer (pH 9.1). Te is preconcentrated by coprecipitation with the generated lanthanum hydroxide precipitate. The precipitate is quantitatively collected in the resin, eluted with hydrochloric acid, and then transferred into the atomizer device. Considering a sample consumption of 25 mL, an enrichment factor of 10 was obtained. The detection limit (3σ) was 0.03 μg/L, and the precision (relative standard deviation) was 3.5% (n = 10) at the 10 μg/L level. The calibration graph using the preconcentration system for Te was linear with a correlation coefficient of 0.9993. Satisfactory results were obtained for the analysis of Te in garlic samples.


2000 ◽  
Vol 83 (6) ◽  
pp. 1423-1428 ◽  
Author(s):  
Kaare Julshamn ◽  
Arngriimur Thorlacius ◽  
Per Lea ◽  
Kjetil Barland ◽  
Kari Eidem ◽  
...  

Abstract Eight laboratories participated in an interlaboratory method performance (collaborative) study of a method for the determination of arsenic in foodstuffs of marine origin by electrothermal atomic absorption spectrometry after wet digestion using a microwave oven technique. The study was preceded by a practice round of familiarization samples. The method was tested on 8 materials (cod roe, krill, blue mussel, saithe, scampi, cod fillet, shrimp, and cod extract) ranging in As content from 2 to 75 mg/kg. The materials were sent to participants in the study as blind duplicates, and the participants were asked to perform single determinations on each sample. Repeatability relative standard deviations (RSDr) for As ranged from 6.8 to 17.4%. Reproducibility relative standard deviations (RSDR) ranged from 7.6 to 24%. The highest RSDR value was found for the sample with the highest concentration of As.


2005 ◽  
Vol 88 (4) ◽  
pp. 1212-1216 ◽  
Author(s):  
Kaare Julshamn ◽  
Per Lea ◽  
Hilde Skaar Norli ◽  
S Floren ◽  
T Furnes ◽  
...  

Abstract Nine laboratories participated in an interlaboratory method performance (collaborative) study of a method for the determination of sodium in foods by flame atomic absorption spectrometry after wet digestion, using a microwave oven technique. Before the study, the laboratories were able to practice on samples with defined sodium levels (pretrial test). The method was tested on a total of 6 foods (broccoli, carrot, bread, saithe fillet, pork, and cheese) with sodium concentrations of 1480–8260 mg/kg. The materials were presented to the participants in the study as blind duplicates, and the participants were asked to perform single determinations for each sample. The repeatability relative standard deviations (RSDr) for sodium ranged from 1.9 to 6.5%. The reproducibility relative standard deviations (RSDR) ranged from 4.2 to 6.9%. The HorRat values ranged from 0.9 to 1.6.


1998 ◽  
Vol 81 (6) ◽  
pp. 1202-1208 ◽  
Author(s):  
Kaare Julshamn ◽  
Amund Maage ◽  
Harriet C Wallin ◽  
◽  
S Lierhagen ◽  
...  

Abstract On the basis of results of the performed collaborative study, the 49th Annual General Meeting of the Nordic Committee on Food Analysis (NMKL) in The Faroe Islands, August 1995, approved this method to be printed and included in NMKL's collection of methods of analysis of foods. Eleven laboratories participated in an interlaboratory methods-performance (collaborative) study of a method for determining magnesium and calcium in foodstuffs by atomic absorption spectrometry (AAS) after wet microwave digestion. The study was preceded by a practice round of familiarization samples. The method was tested on 7 materials: 5 foods (apple, milk powder, minced fish, wheat bran, and chocolate cake) and 2 composite diets ranging in Mg content from 240 to 3900 mg/kg and in Ca content from 290 to 9300 mg/kg. The materials were presented to study participants as blind duplicates, and participants were asked to perform single determinations on each sample. Repeatability relative standard deviations (RSDr) ranged from 1.9 to 4.9% for Mg and from 2.2 to 8.1 % for Ca. Reproducibility relative standard deviations (RSDR) ranged from 4.0 to 13% for Mg and from 5.9 to 23% for Ca. For Ca, lowest RSDR values were found for samples with high concentrations of Ca (>3800 mg/kg sample) and with nitrate ion residues of <1.3% (w/v).


1986 ◽  
Vol 69 (6) ◽  
pp. 1009-1013
Author(s):  
Willem G De Ruig ◽  
◽  
C H Gast ◽  
A H M Grimbergen ◽  
B Guis ◽  
...  

Abstract A draft standard method is presented for the determination of Ca, Cu, Fe, Mg, Mn, K, Na, and Zn in animal feeding stuffs. The method specifies dry ashing of samples and detection by atomic absorption spectrometry (AAS). The applicability of the method for various concentrations of the elements was tested in a series of 3 collaborative studies. The feeding stuffs investigated include pulp pellets, grass, mixed feed, fish meal, milk powder, maize, sheep feed, lupin, milocorn, feather meal, and blood meal. Relative standard deviations, repeatability, and reproducibility are given. The reproducibility of the method was acceptable for the following approximate minimum quantities: Na and K, 1000 mg/kg; Ca and Mg, 100 mg/kg; Zn, Mn, and Cu, 10 mg/ kg; Fe, 10-200 mg/kg, depending on the product.


2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.


1997 ◽  
Vol 80 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Carmen Cabrera-Vique ◽  
Pierra-Louis Teissedre ◽  
Marie-Thérèse Cabanis ◽  
Jean-Claude Cabanis

Abstract A method based on graphite furnace atomic absorption spectrometry (GFAAS) was developed for determining platinum in wine. Wine samples were prepared by microwave acid digestion or dry mineralization. The method of standard addition was used for Pt determination in untreated wine samples and mineralized samples. Analyte modifiers and furnace conditions were optimized. Effects of cations (Mg2+, Ca2+, K+, Na+, and NH|) and anions (PO43, SO42) were tested separately and in combination. Analytical characteristics of the method were optimized for analyte recovery and signal enhancement. Recoveries ranged from 92.5 to 102%, and precision reproducibility relative standard deviation varied from 7.5 to 10%. Red, rosé, and white wines from France were analyzed. Platinum levels found in most wines were very low (<10 μg/L).


1996 ◽  
Vol 79 (3) ◽  
pp. 764-768 ◽  
Author(s):  
Oroncio Jiménez De Blas ◽  
N Rodriguez Mateos ◽  
A Garcia Sanchez

Abstract A procedure has been developed for determination of total arsenic and selenium in soils and plants by atomic absorption spectrometry with hydride generation associated with flow injection analysis (FIA-AAS-HG). Samples were wet-digested by using 2 systems: heating in a metal digestion block with controlled temperature and time and heating in a microwave oven. Total arsenic and selenium were reduced with NaBH4 and concentrated HCI, respectively. In both digestion systems used for the 2 matrix types, detection limits below 1 μg/L were found for both elements for an injection volume of 160 μL, with relative standard deviations of 3–6%. Recoveries by the method ranged from 93 to 105%; with the reference materials FD8 and MRG-1, the values obtained in all cases were consistent with the certified data. The FIA-AAS-HG procedure is highly suitable for determination of total arsenic and selenium in soils and plants, and because of the coupled system used, it is an improvement over other procedures in terms of sample treatment, sample consumption, and automation.


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