title: Content of trace elements and chromium speciation in Neem powder and tea infusions.
abstract: Total concentrations of selected trace elements in Neem powder and in Neem tea were determined by inductively coupled plasma mass spectrometry (ICP-MS). The data revealed that despite high total concentrations of the potentially toxic elements Al and Ni in Neem powder, their amounts dissolved in Neem tea were low. Total concentrations of the other toxic elements Pb, As and Cd were also very low and do not represent a health hazard. In contrast, total concentrations of the essential elements Fe, Cu, Zn, Se Mo and Cr in Neem powder were high and also considerable in Neem tea. Consuming one cup of Neem tea (2g per 200 mL of water) covers the recommended daily intakes for Cr and Se and represents an important source of Mo and Cu. Speciation analysis of Cr by high performance liquid chromatography (HPLC) coupled to ICP-MS with the use of enriched Cr isotopic tracers to follow species interconversions during the analytical procedure demonstrated that toxic Cr(VI) was not present either in Neem powder or in Neem tea. Its concentrations were below the limits of detection of the HPLC-ICP-MS procedure applied. The speciation analysis data confirmed that even Cr(VI) was added, it was rapidly reduced by the presence of antioxidants in Neem leaves. By the use of enriched Cr isotopic spike solutions it was also demonstrated that for obtaining reliable analytical data it is essential to apply the extraction procedures which prevent Cr species interconversions, or to correct for species transformation.
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Breda
authors.initials: B
authors.lastname: Novotnik
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Tea
authors.initials: T
authors.lastname: Zuliani
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Ščančar
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia. Electronic address: radmila.milacic@ijs.si.
authors.forename: Radmila
authors.initials: R
authors.lastname: Milačič
mesh_terms: D001151:Arsenic / Q000032:analysis / Q000633:toxicity; D031601:Azadirachta / Q000737:chemistry*; D001628:Beverages / Q000009:adverse effects / Q000032:analysis*; D002857:Chromium / Q000032:analysis* / Q000737:chemistry / Q000506:poisoning; D019587:Dietary Supplements / Q000032:analysis*; D020834:Ethnopharmacology; D005506:Food Contamination; D005513:Food Inspection / Q000379:methods*; D057141:Food, Preserved / Q000009:adverse effects / Q000032:analysis*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008519:Medicine, Traditional; D019216:Metals, Heavy / Q000032:analysis / Q000633:toxicity; D009753:Nutritive Value; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D017524:Slovenia; D013054:Spectrophotometry, Atomic; D014131:Trace Elements / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D010936:Plant Extracts; D014131:Trace Elements; D002857:Chromium; D001151:Arsenic
keywords: Chromium speciation; Enriched stable isotopic solutions of chromium; High performance liquid chromatography–inductively coupled plasma mass spectrometry; Neem powder; Trace elements