Iodine determination in food by inductively coupled plasma mass spectrometry after digestion by microwave-induced combustion
| Autor: | Valderi L. Dressler, Marcia F. Mesko, Cezar A. Bizzi, Guenter Knapp, Paola A. Mello, Erico M.M. Flores |
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| Rok vydání: | 2010 |
| Předmět: |
Detection limit
Tetramethylammonium hydroxide Chromatography Meat Chemistry Microwave oven Extraction (chemistry) Flour food and beverages Biochemistry Mass Spectrometry Analytical Chemistry chemistry.chemical_compound Digestion (alchemy) Certified reference materials Milk Limit of Detection Animals Sample preparation Cattle Microwaves Inductively coupled plasma mass spectrometry Food Analysis Iodine |
| Zdroj: | Analytical and bioanalytical chemistry. 398(2) |
| ISSN: | 1618-2650 |
| Popis: | Iodine determination in food samples was performed by inductively coupled plasma mass spectrometry (ICP-MS) after digestion by microwave-induced combustion (MIC). Sample masses up to 500 mg of bovine liver, corn starch, milk powder, or wheat flour were completely combusted using the MIC system. Ammonium nitrate (6 mol l(-1) solution, 50 μl) was used as an aid for ignition and vessels were charged with 15 bar of O(2). The use of H(2)O, 0.9 mmol l(-1) H(2)O(2), 10 to 50 mmol l(-1) (NH(4))(2)CO(3) and 56 mmol l(-1) tetramethylammonium hydroxide was investigated as absorbing solutions, as well as the suitability of performing a reflux step after the combustion process. Digestion of food samples by pressurized microwave-assisted acid digestion, microwave-assisted extraction and conventional extraction of iodine in alkaline solution were also evaluated. Iodine recoveries higher than 99% were obtained using MIC and 50 mmol l(-1) (NH(4))(2)CO(3) or 56 mmol l(-1) tetramethylammonium hydroxide as absorbing solution and with 5 min for the reflux step. Accuracy was evaluated using certified reference materials (bovine muscle, corn bran, and milk powder) and agreement better than 97% was obtained. The limit of quantification by MIC and further ICP-MS determination was 0.002 µg g(-1). Blanks were always low and no memory effects were observed. Digestion by MIC allowed the processing of up to eight samples by each run in 25 min with high efficiency of digestion (residual carbon content lower than 1%) providing a suitable medium for further iodine determination by ICP-MS. |
| Databáze: | OpenAIRE |
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