title: Method development and inter-laboratory comparison about the determination of titanium from titanium dioxide nanoparticles in tissues by inductively coupled plasma mass spectrometry.
abstract: Nanosized titanium dioxide (TiO2) is one of the most interesting and valuable nanomaterials for the construction industry but also in health care applications, food, and consumer goods, e.g., cosmetics. Therefore, the properties associated with this material are described in detail. Despite its widespread use, the analytical determination and characterization of nanosized metal oxides is not as straightforward as the comparatively easy-to-detect metallic nanoparticles (e.g., silver or gold). This study presents the method development and the results of the determination of tissue titanium (Ti) levels after treatment of rats with the nanosized TiO2. Total Ti levels were chosen to evaluate the presence and distribution of TiO2 nanoparticles. A procedure consisting of incubation with a mixture of nitric acid (HNO3) and hydrofluoric acid (HF), and heating was developed to digest tissues and TiO2 nanomaterials in order to determine the total Ti content by inductively coupled plasma mass spectrometry (ICPMS). For the inter-laboratory comparison, altogether four laboratories analyzed the same samples upon digestion using the available ICPMS equipment. A major premise for any toxicokinetic study is the possibility to detect the chemical under investigation in biological samples (tissues). So, the study has to be performed with a dose high enough to allow for subsequent tissue level measurement of the chemical under investigation. On the other hand, dose of the chemical applied should not induce over toxicity in the animal as this may affect its absorption, distribution, metabolism, and excretion. To determine a non-toxic TiO2 dosage, an acute toxicity study in rats was performed, and the organs obtained were evaluated for the presence of Ti by ICPMS. Despite the differences in methodology and independent of the sample preparation and the ICPMS equipment used, the results obtained for samples with Ti concentrations >4 μg Ti/g tissue agreed well.
authors.affiliation: Philips Innovation Services (PInS), High Tech Campus 11, 5656 AE, Eindhoven, The Netherlands, petra.krystek@philips.com.
authors.forename: Petra
authors.initials: P
authors.lastname: Krystek
authors.forename: Jutta
authors.initials: J
authors.lastname: Tentschert
authors.forename: Yacine
authors.initials: Y
authors.lastname: Nia
authors.forename: Benedicte
authors.initials: B
authors.lastname: Trouiller
authors.forename: Laurent
authors.initials: L
authors.lastname: Noël
authors.forename: Mario E
authors.initials: ME
authors.lastname: Goetz
authors.forename: Arnaud
authors.initials: A
authors.lastname: Papin
authors.forename: Andreas
authors.initials: A
authors.lastname: Luch
authors.forename: Thierry
authors.initials: T
authors.lastname: Guérin
authors.forename: Wim H
authors.initials: WH
authors.lastname: de Jong
mesh_terms: D000825:Animal Structures / Q000737:chemistry*; D000818:Animals; D007753:Laboratories / Q000592:standards; D008297:Male; D013058:Mass Spectrometry / Q000379:methods* / Q000592:standards; D053758:Nanoparticles / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D014025:Titanium / Q000032:analysis*
chemical_list: C009495:titanium dioxide; D014025:Titanium