References:

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[1]Amendola, V., Meneghetti, M., 2009. Size evaluation of gold nanoparticles by UV-vis spectroscopy. The Journal of Physical Chemistry C, 113(11):4277-4285.

[2]Baalousha, M., Kammer, F.V.D., Motelica-Heino, M., et al., 2006. Size-based speciation of natural colloidal particles by flow field flow fractionation, inductively coupled plasma-mass spectroscopy, and transmission electron microscopy/X-ray energy dispersive spectroscopy: colloids-trace element interaction. Environmental Science & Technology, 40(7):2156-2162.

[3]Baalousha, M., Stolpe, B., Lead, J.R., 2011. Flow field-flow fractionation for the analysis and characterization of natural colloids and manufactured nanoparticles in environmental systems: a critical review. Journal of Chromatography A, 1218(27):4078-4103.

[4]Baik, M.H., Yun, J.I., Bouby, M., et al., 2007. Characterization of aquatic groundwater colloids by a laser-induced breakdown detection and ICP-MS combined with an asymmetric flow field-flow fractionation. Korean Journal of Chemical Engineering, 24(5):723-729.

[5]Benn, T.M., Pycke, B.F.G., Herckes, P., et al., 2011. Evaluation of extraction methods for quantification of aqueous fullerenes in urine. Analytical and Bioanalytical Chemistry, 399(4):1631-1639.

[6]Bogner, A., Thollet, G., Basset, D., et al., 2005. Wet STEM: a new development in environmental SEM for imaging nano-objects included in a liquid phase. Ultramicroscopy, 104(3-4):290-301.

[7]Bootz, A., Vogel, V., Schubert, D., et al., 2004. Comparison of scanning electron microscopy, dynamic light scattering and analytical ultracentrifugation for the sizing of poly (butyl cyanoacrylate) nanoparticles. European Journal of Pharmaceutics and Biopharmaceutics, 57(2):369-375.

[8]Brar, S.K., Verma, M., 2011. Measurement of nanoparticles by light-scattering techniques. TrAC Trends in Analytical Chemistry, 30(1):4-17.

[9]Carlotti, M.E., Ugazio, E., Sapino, S., et al., 2009. Role of particle coating in controlling skin damage photoinduced by titania nanoparticles. Free Radical Research, 43(3):312-322.

[10]Celiz, M.D., Colon, L.A., Watson, D.F., et al., 2011. Study on the effects of humic and fulvic acids on quantum dot nanoparticles using capillary electrophoresis with laser- induced fluorescence detection. Environmental Science & Technology, 45(7):2917-2924.

[11]Chen, C.Y., 2010. Biologcial Effects of Titanium Dioxide Nanomaterials and Its Safe Application. Scientific Press, Beijing, China, p.2-3 (in Chinese).

[12]Cheng, J.X., Jia, Y.K., Zheng, G.F., et al., 2002. Laser- scanning coherent anti-stokes Raman scattering microscopy and applications to cell biology. Biophysical Journal, 83(1):502-509.

[13]Cho, E.J., Holback, H., Liu, K.C., et al., 2013. Nanoparticle characterization: state of the art, challenges, and emerging technologies. Molecular Pharmaceutics, 10(6):2093- 2110.

[14]da Silva, B.F., Pérez, S., Gardinalli, P., et al., 2011. Analytical chemistry of metallic nanoparticles in natural environments. TrAC Trends in Analytical Chemistry, 30(3):528-540.

[15]Domingos, R.F., Baalousha, M.A., Ju-Nam, Y., et al., 2009. Characterizing manufactured nanoparticles in the environment: multimethod determination of particle sizes. Environmental Science & Technology, 43(19):7277-7284.

[16]Dreissig, I., Weiss, S., Hennig, C., et al., 2011. Formation of uranium(IV)-silica colloids at near-neutral pH. Geochimica et Cosmochimica Acta, 75(2):352-367.

[17]Du, W.C., Sun, Y.Y., Ji, R., et al., 2011. TiO₂ and ZnO nanoparticles negatively affect wheat growth and soil enzyme activities in agricultural soil. Journal of Environmental Monitoring, 13(4):822-828.

[18]Duarte, K., Justino, C.I.L., Freitas, A.C., et al., 2014. Direct-reading methods for analysis of volatile organic compounds and nanoparticles in workplace air. TrAC Trends in Analytical Chemistry, 53:21-32.

[19]Fabricius, A.L., Duester, L., Meermann, B., et al., 2014. ICP- MS-based characterization of inorganic nanoparticles- sample preparation and off-line fractionation strategies. Analytical and Bioanalytical Chemistry, 406(2):467-479.

[20]Fadeel, B., Garcia-Bennett, A.E., 2010. Better safe than sorry: understanding the toxicological properties of inorganic nanoparticles manufactured for biomedical applications. Advanced Drug Delivery Reviews, 62(3):362-374.

[21]Farkas, J., Peter, H., Christian, P., et al., 2011. Characterization of the effluent from a nanosilver producing washing machine. Environment International, 37(6):1057-1062.

[22]Farré, M., Gajda-Schrantz, K., Kantiani, L., et al., 2009. Ecotoxicity and analysis of nanomaterials in the aquatic environment. Analytical and Bioanalytical Chemistry, 393(1):81-95.

[23]Gallego-Urrea, J.A., Tuoriniemi, J., Pallander, T., et al., 2010. Measurements of nanoparticle number concentrations and size distributions in contrasting aquatic environments using nanoparticle tracking analysis. Environmental Chemistry, 7(1):67-81.

[24]Gallego-Urrea, J.A., Tuoriniemi, J., Hassellöv, M., 2011. Applications of particle-tracking analysis to the determination of size distributions and concentrations of nanoparticles in environmental, biological and food samples. TrAC Trends in Analytical Chemistry, 30(3):473-483.

[25]Gao, Y., Luo, Z.X., He, N.P., et al., 2013. Metallic nanoparticle production and consumption in China between 2000 and 2010 and associative aquatic environmental risk assessment. Journal of Nanoparticle Research, 15(6):1681-1690.

[26]Gimbert, L.J., Haygarth, P.M., Beckett, R., et al., 2005. Comparison of centrifugation and filtration techniques for the size fractionation of colloidal material in soil suspensions using sedimentation field-flow fractionation. Environmental Science & Technology, 39(6):1731-1735.

[27]Gottschalk, F., Sun, T., Nowack, B., 2013. Environmental concentrations of engineered nanomaterials: review of modeling and analytical studies. Environmental Pollution, 181:287-300.

[28]Gray, E.P., Bruton, T.A., Higgins, C.P., et al., 2012. Analysis of gold nanoparticle mixtures: a comparison of hydrodynamic chromatography (HDC) and asymmetrical flow field-flow fractionation (AF4) coupled to ICP-MS. Journal of Analytical Atomic Spectrometry, 27(9):1532- 1539.

[29]Grogan, J.M., Rotkina, L., Bau, H.H., 2011. In situ liquid-cell electron microscopy of colloid aggregation and growth dynamics. Physical Review E, 83(6):061405.

[30]Hassellöv, M., Readman, J.W., Ranville, J.F., et al., 2008. Nanoparticle analysis and characterization methodologies in environmental risk assessment of engineered nanoparticles. Ecotoxicology, 17(5):344-361.

[31]Helmbrecht, C., Niessner, R., Haisch, C., 2011. Photophoretic velocimetry—a new way for the in situ determination of particle size distribution and refractive index of hydrocolloids. Analyst, 136(9):1987-1994.

[32]Hendren, C.O., Mesnard, X., Droge, J., et al., 2011. Estimating production data for five engineered nanomaterials as a basis for exposure assessment. Environmental Science & Technology, 45(7):2562-2569.

[33]Howard, A.G., 2010. On the challenge of quantifying man-made nanoparticles in the aquatic environment. Journal of Environmental Monitoring, 12(1):135-142.

[34]Hussain, S., Vanoirbeek, J.A.J., Luyts, K., et al., 2011. Lung exposure to nanoparticles modulates an asthmatic response in a mouse model. European Respiratory Journal, 37(2):299-309.

[35]Johnson, A.C., Bowes, M.J., Crossley, A., et al., 2011. An assessment of the fate, behaviour and environmental risk associated with sunscreen TiO₂ nanoparticles in UK field scenarios. Science of the Total Environment, 409(13):2503-2510.

[36]Ju-Nam, Y., Lead, J.R., 2008. Manufactured nanoparticles: an overview of their chemistry, interactions and potential environmental implications. Science of the Total Environment, 400(1-3):396-414.

[37]Kaegi, R., Ulrich, A., Sinnet, B., et al., 2008. Synthetic TiO₂ nanoparticle emission from exterior facades into the aquatic environment. Environmental Pollution, 156(2):233-239.

[38]Khosravi, K., Hoque, M.E., Dimock, B., et al., 2012. A novel approach for determining total titanium from titanium dioxide nanoparticles suspended in water and biosolids by digestion with ammonium persulfate. Analytica Chimica Acta, 713:86-91.

[39]Kirby, B.J., Hasselbrink, E.F., 2004. Zeta potential of microfluidic substrates: 2. Data for polymers. Electrophoresis, 25(2):203-213.

[40]Kiser, M.A., Westerhoff, P., Benn, T., et al., 2009. Titanium nanomaterial removal and release from wastewater treatment plants. Environmental Science & Technology, 43(17):6757-6763.

[41]Kiser, M.A., Ladner, D., Hristovski, K.D., et al., 2012. Nanomaterial transformation and association with fresh and freeze-dried wastewater activated sludge: implications for testing protocol and environmental fate. Environmental Science & Technology, 46(13):7046-7053.

[42]Laborda, F., Jimenez-Lamana, J., Bolea, E., et al., 2011. Selective identification, characterization and determination of dissolved silver(I) and silver nanoparticles based on single particle detection by inductively coupled plasma mass spectrometry. Journal of Analytical Atomic Spectrometry, 26(7):1362-1371.

[43]Landsiedel, R., Ma-Hock, L., Kroll, A., et al., 2010. Testing metal-oxide nanomaterials for human safety. Advanced Materials, 22(24):2601-2627.

[44]Larner, F., Rehkamper, M., 2012. Evaluation of stable isotope tracing for ZnO nanomaterials-new constraints from high precision isotope analyses and modeling. Environmental Science & Technology, 46(7):4149-4158.

[45]Latkoczy, C., Kagi, R., Fierz, M., et al., 2010. Development of a mobile fast-screening laser-induced breakdown detection (LIBD) system for field-based measurements of nanometre sized particles in aqueous solutions. Journal of Environmental Monitoring, 12(7):1422-1429.

[46]Lee, J.H., Kwon, M., Ji, J.H., et al., 2011. Exposure assessment of workplaces manufacturing nanosized TiO₂ and silver. Inhalation Toxicology, 23(4):226-236.

[47]Leppard, G.G., 2008. Nanoparticles in the environment as revealed by transmission electron microscopy: detection, characterisation and activities. Current Nanoscience, 4(3):278-301.

[48]Lespes, G., Gigault, J., 2011. Hyphenated analytical techniques for multidimensional characterisation of submicron particles: a review. Analytica Chimica Acta, 692(1-2):26-41.

[49]Li, S., Wallis, L.K., Ma, H., et al., 2014a. Phototoxicity of TiO₂ nanoparticles to a freshwater benthic amphipod: are benthic systems at risk? The Science of the Total Environment, 466-467:800-808.

[50]Li, S., Wallis, L.K., Diamond, S.A., et al., 2014b. Species sensitivity and dependence on exposure conditions impacting the phototoxicity of TiO₂ nanoparticles to benthic organisms. Environmental Toxicology and Chemistry, 33(7):1563-1569.

[51]Lin, D.H., Ji, J., Long, Z.F., et al., 2012. The influence of dissolved and surface-bound humic acid on the toxicity of TiO₂ nanoparticles to Chlorella sp. Water Research, 46(14):4477-4487.

[52]Liu, J.F., Yu, S.J., Yin, Y.G., et al., 2012. Methods for separation, identification, characterization and quantification of silver nanoparticles. TrAC Trends in Analytical Chemistry, 33:95-106.

[53]Lomer, M.C.E., Thompson, R.P.H., Powell, J.J., 2002. Fine and ultrafine particles of the diet: influence on the mucosal immune response and association with Crohn’s disease. Proceedings of the Nutrition Society, 61(1):123-130.

[54]Luo, H., Scriven, L.E., Francis, L.F., 2007. Cryo-SEM studies of latex/ceramic nanoparticle coating microstructure development. Journal of Colloid and Interface Science, 316(2):500-509.

[55]Luo, P., Morrison, I., Dudkiewicz, A., et al., 2013. Visualization and characterization of engineered nanoparticles in complex environmental and food matrices using atmospheric scanning electron microscopy. Journal of Microscopy, 250(1):32-41.

[56]Luo, Z.X., Wang, Z.H., Li, Q.Z., et al., 2011. Spatial distribution, electron microscopy analysis of titanium and its correlation to heavy metals: occurrence and sources of titanium nanomaterials in surface sediments from Xiamen Bay, China. Journal of Environmental Monitoring, 13(4):1046-1052.

[57]Ma, X.M., Geiser-Lee, J., Deng, Y., et al., 2010. Interactions between engineered nanoparticles (ENPs) and plants: phytotoxicity, uptake and accumulation. Science of the Total Environment, 408(16):3053-3061.

[58]Macwan, D.P., Dave, P.N., Chaturvedi, S., 2011. A review on nano-TiO₂ sol-gel type syntheses and its applications. Journal of Materials Science, 46(11):3669-3686.

[59]Mahshid, S., Askari, M., Ghamsari, M.S., 2007. Synthesis of TiO₂ nanoparticles by hydrolysis and peptization of titanium isopropoxide solution. Journal of Materials Processing Technology, 189(1-3):296-300.

[60]Marra, J., Voetz, M., Kiesling, H.J., 2010. Monitor for detecting and assessing exposure to airborne nanoparticles. Journal of Nanoparticle Research, 12(1):21-37.

[61]Maynard, A.D., Aitken, R.J., Butz, T., et al., 2006. Safe handling of nanotechnology. Nature, 444(7117):267-269.

[62]Menard, A., Drobne, D., Jemec, A., 2011. Ecotoxicity of nanosized TiO₂. Review of in vivo data. Environmental Pollution, 159(3):677-684.

[63]Mitrano, D., Ranville, J., Neubauer, K., et al., 2012. Field-flow-fractionation coupled with ICP-MS for the analysis of engineered nanoparticles in environmental samples. Spectroscopy, 27(9):36-44.

[64]Murdock, R.C., Braydich-Stolle, L., Schrand, A.M., et al., 2008. Characterization of nanomaterial dispersion in solution prior to in vitro exposure using dynamic light scattering technique. Toxicological Sciences, 101(2):239-253.

[65]Neal, C., Jarvie, H., Rowland, P., et al., 2011. Titanium in UK rural, agricultural and urban/industrial rivers: geogenic and anthropogenic colloidal/sub-colloidal sources and the significance of within-river retention. Science of the Total Environment, 409(10):1843-1853.

[66]O'Connell, M.J., Bachilo, S.M., Huffman, C.B., et al., 2002. Band gap fluorescence from individual single-walled carbon nanotubes. Science, 297(5581):593-596.

[67]Piccinno, F., Gottschalk, F., Seeger, S., et al., 2012. Industrial production quantities and uses of ten engineered nanomaterials in Europe and the world. Journal of Nanoparticle Research, 14(9):1109.

[68]Pietra, F., Rabouw, F.T., Evers, W.H., et al., 2012. Semiconductor nanorod self-assembly at the liquid/air interface studied by in situ GISAXS and ex situ TEM. Nano Letters, 12(11):5515-5523.

[69]Plathe, K.L., von der Kammer, F., Hassellöv, M., et al., 2010. Using FlFFF and aTEM to determine trace metal- nanoparticle associations in riverbed sediment. Environmental Chemistry, 7(1):82-93.

[70]Robichaud, C.O., Uyar, A.E., Darby, M.R., et al., 2009. Estimates of upper bounds and trends in nano-TiO₂ production as a basis for exposure assessment. Environmental Science & Technology, 43(12):4227-4233.

[71]Schmid, K., Riediker, M., 2008. Use of nanoparticles in Swiss industry: a targeted survey. Environmental Science & Technology, 42(7):2253-2260.

[72]Schmid, T., Burkhard, J., Yeo, B.S., et al., 2008. Towards chemical analysis of nanostructures in biofilms I: imaging of biological nanostructures. Analytical and Bioanalytical Chemistry, 391(5):1899-1905.

[73]Shi, H., Magaye, R., Castranova, V., et al., 2013. Titanium dioxide nanoparticles: a review of current toxicological data. Particle and Fibre Toxicology, 10(1):15.

[74]Stiles, P.L., Dieringer, J.A., Shah, N.C., et al., 2008. Surface-enhanced Raman spectroscopy. Annual Review of Analytical Chemistry, 1(1):601-626.

[75]Stone, V., Nowack, B., Baun, A., et al., 2010. Nanomaterials for environmental studies: classification, reference material issues, and strategies for physico-chemical characterisation. Science of the Total Environment, 408(7):1745-1754.

[76]Surugau, N., Urban, P.L., 2009. Electrophoretic methods for separation of nanoparticles. Journal of Separation Science, 32(11):1889-1906.

[77]Thang, N.M., Knopp, R., Geckeis, H., et al., 2000. Detection of nanocolloids with flow-field flow fractionation and laser-induced breakdown detection. Analytical Chemistry, 72(1):1-5.

[78]Thieme, J., McNulty, I., Vogt, S., et al., 2007. X-ray spectromicroscopy—a tool for environmental sciences. Environmental Science & Technology, 41(20):6885-6889.

[79]Tiede, K., Boxall, A.B.A., Tear, S.P., et al., 2008. Detection and characterization of engineered nanoparticles in food and the environment. Food Additives & Contaminants: Part A, 25(7):795-821.

[80]Tiede, K., Hassellöv, M., Breitbarth, E., et al., 2009. Considerations for environmental fate and ecotoxicity testing to support environmental risk assessments for engineered nanoparticles. Journal of Chromatography A, 1216(3):503-509.

[81]Tiede, K., Boxall, A.B.A., Wang, X.M., et al., 2010. Application of hydrodynamic chromatography-ICP-MS to investigate the fate of silver nanoparticles in activated sludge. Journal of Analytical Atomic Spectrometry, 25(7):1149-1154.

[82]Tsao, T.M., Chen, Y.M., Wang, M.K., 2011. Origin, separation and identification of environmental nanoparticles: a review. Journal of Environmental Monitoring, 13(5):1156-1163.

[83]van Broekhuizen, P., van Broekhuizen, F., Cornelissen, R., et al., 2011. Use of nanomaterials in the European construction industry and some occupational health aspects thereof. Journal of Nanoparticle Research, 13(2):447-462.

[84]van Broekhuizen, P., van Broekhuizen, F., Cornelissen, R., et al., 2012. Workplace exposure to nanoparticles and the application of provisional nanoreference values in times of uncertain risks. Journal of Nanoparticle Research, 14(4):770.

[85]von der Kammer, F., Legros, S., Larsen, E.H., et al., 2011. Separation and characterization of nanoparticles in complex food and environmental samples by field-flow fractionation. TrAC Trends in Analytical Chemistry, 30(3):425-436.

[86]Walther, C., Cho, H.R., Fanghanel, T., 2004. Measuring multimodal size distributions of aquatic colloids at trace concentrations. Applied Physics Letters, 85(26):6329- 6331.

[87]Weinberg, H., Galyean, A., Leopold, M., 2011. Evaluating engineered nanoparticles in natural waters. TrAC Trends in Analytical Chemistry, 30(1):72-83.

[88]Weir, A., Westerhoff, P., Fabricius, L., et al., 2012. Titanium dioxide nanoparticles in food and personal care products. Environmental Science & Technology, 46(4):2242-2250.

[89]Westerhoff, P., Song, G.X., Hristovski, K., et al., 2011. Occurrence and removal of titanium at full scale wastewater treatment plants: implications for TiO₂ nanomaterials. Journal of Environmental Monitoring, 13(5):1195-1203.

[90]Windler, L., Lorenz, C., von Goetz, N., et al., 2012. Release of titanium dioxide from textiles during washing. Environmental Science & Technology, 46(15):8181-8188.

[91]Wyatt, P.J., 1993. Light-scattering and the absolute characterization of macromolecules. Analytica Chimica Acta, 272(1):1-40.

[92]Xiao, Y., Wiesner, M.R., 2012. Characterization of surface hydrophobicity of engineered nanoparticles. Journal of Hazardous Materials, 215-216:146-151.

[93]Yotsumoto, H., Yoon, R.H., 1993. Application of extended DLVO theory: I. Stability of rutile suspensions. Journal of Colloid and Interface Science, 157(2):426-433.

[94]Zänker, H., Schierz, A., 2012. Engineered nanoparticles and their identification among natural nanoparticles. Annual Review of Analytical Chemistry, 5(1):107-132.