This chapter deals with carbon and carbon nanotubes. Copper is one of a relatively small group of metallic elements that are essential for human, plant, and animal enzymes. Copper ions are introduced into human and animal bodies by food, water, air, etc. Copper enters the marine environment primarily from riverine transport and aerosols. Anthropogenic and geothermal sources can also be included. Depending on its concentration, copper may be a hazard to aquatic organisms. Nanomaterials based on only saturated carbon atoms, also known as carbon nanotubes, in both single-walled carbon nanotubes and multiwalled carbon nanotubes (MWCNTs), are becoming potential sorbents for metal ions due to their unique electronic, mechanical, and chemical properties. The aim of this work is to develop a reliable flow injection preconcentration system coupled to UV-V is molecular spectrophotometry for copper determination using MWCNT as sorbent.This system is the first one that demonstrates the powerful application of MWCNT in the field of solid-phase preconcentration using spectrophotometric determination, a technique naturally less selective than atomic absorption spectrometry. © 2010 Elsevier B.V. All rights reserved. 177198(2002) Toxicological profile for copper draft for public comment, , Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services, Public Health Service, Atlanta (GA)Merian, E., Anke, M., Ihnat, M., Stoeppler, M., (2004) Elements and their compounds in the environment, , John Wiley, WeinheimFleming, C.A., Trevors, J.T., Copper toxicity and chemistry in the environment a review (1989) Water Air Soil Pollut, 44, pp. 143-158Tarley, C.R.T., Dos Santos, W.N.L., Dos Santos, C.M., Ferreira, S.L.C., Arruda, M.A.Z., Factorial design and Doehlert matrix in optimization of flow system for preconcentration of copper on polyurethane foam loaded with 4-(2-pyridylazo)-resorcinol (2004) Anal. Letters, 37, pp. 1437-1455de Peña, Y.P., López, W., Burguera, J.L., Burguera, M., Gallignani, M., Brunetto, R., Synthetic zeolites as sorbent material for on-line preconcentration of copper traces and its determination using flame atomic absorption spectrometry (2000) Anal Chim Acta, 403, pp. 249-258Sweileh, J.A., Sorption of trace metals on human hair and application for cadmium and lead pre-concentration with flame atomic absorption determination (2003) Anal Bioanal Chem, 375, pp. 450-455Anthemidis, A.N., Zachariadis, G.A., Farastelis, C.G., Stratis, J.A., On-line liquid-liquid extraction system using a new phase separator for flame atomic absorption spectrometric determination of ultra-trace cadmium in natural waters (2004) Talanta, 62, pp. 437-443Lemos, V.A., Santos, E.S., Santos, M.S., Yamaki, R.T., Thiazolylazo dyes and their application in analytical methods (2007) Microchim Acta, 158, pp. 189-204Akl, M.A., An improved colorimetric determination of lead(II) in the presence of nonionic surfactant (2006) Anal Sci, 22, pp. 1227-1231Bonifácio, V.G., Figueiredo-Filho, L.C., Marcolino Jr, L.H., Fatibello-Filho, O., An improved flow system for chloride determination in natural waters exploiting solid-phase reactor and long pathlength spectrophotometry (2007) Talanta, 72, pp. 663-667Bashammakh, A.S., Bahaffi, S.O., Al-Sibaai, A.A., Al-Wael, H.O., El-Shahawi, M.S., Extractive liquid-liquid spectrophotometric procedure for the determination of thiocyanate ions employing the ion pair reagent amiloride monohydrochloride (2007) Anal Chim Acta, 592, pp. 16-23Figueiredo, E.C., Tarley, C.R.T., Kubota, L.T., Rath, S., Arruda, M.A.Z., On-line molecularly imprinted solid phase extraction for the selective spectrophotometric determination of catechol (2007) Microchem J, 85, pp. 290-296Filik, H., Tayman, A., A new cloud-point preconcentration approach for the spectrophotometric determination of p-aminophenol in the presence of paracetamol with 2-(2-hydroxyphenyl)-1H-benzimidazole as a coupling reagent (2007) J Anal Chem, 62, pp. 530-535Gama, E.M., da Silva Lima, A., Lemos, V.A., Preconcentration system for cadmium and lead determination in environmental samples using polyurethane foam/Me-BTANC (2006) J Hazard Mater, 136, pp. 757-762Bilba, D., Bejan, D., Tofan, L., Chelating sorbents in inorganic chemical analysis (1998) Croat Chem Acta, 71, pp. 155-178Liu, G., Wang, J., Zhu, Y., Zhang, X., Application of multiwalled carbon nanotubes as a solid-phase extraction sorbent for chlorobenzenes (2004) Anal Lett, 14, pp. 3085-3104Liang, P., Shi, T., Jing, L.I., Nanometer-size titanium dioxide separation/preconcentration and FAAS determination of trace Zn and Cd in water sample (2004) Int J Environ Anal Chem, 84, pp. 315-321Hang, C., Hu, B., Jiang, Z., Zhang, N., Simultaneous on-line preconcentration and determination of trace metals in environmental samples using a modified nanometer-sized alumina packed micro-column by flow injection combined with ICP-OES (2007) Talanta, 71, pp. 1239-1245Chiang, I.W., Brinson, B.E., Smalley, R.E., Margrave, J.L., Hauge, R.H., Purification and characterization of single-wall carbon nanotubes (2001) J Phys Chem B, 105, pp. 1157-1161Liang, P., Liu, Y., Guo, L., Zeng, J., Lu, H., Multiwalled carbon nanotubes as solid-phase extraction adsorbent for the preconcentration of trace metal ions and their determination by inductively coupled plasma atomic emission spectrometry (2004) J Anal At Spectrom, 19, pp. 1489-1492Tarley, C.R.T., Barbosa, A.F., Segatelli, M.G., Figueiredo, E.C., Luccas, P.O., Highly improved sensitivity of TS-FF-AAS for Cd(II) determination at ng L-1 levels using a simple flow injection minicolumn preconcentration system with multiwall carbon nanotubes (2006) J Anal At Spectrom, 11, pp. 1305-1313Barbosa, A.F., Segatelli, M.G., Pereira, A.C., Santos, A.S., Kubota, L.T., Luccas, P.O., Solid-phase extraction system of Pb (II) ions enrichment based on multiwall carbon nanotubes couple on-line to flame atomic absorption spectrometry (2007) Talanta, 71, pp. 1512-1519Duran, C., Gundogdu, A., Bulut, V.N., Soylak, M., Elci, L., Sentürk, H.B., Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS) (2007) J Hazard Mater, 146, pp. 347-355dos Santos, W.N.L., Santos, C.M., Ferreira, S.L.C., Application of three-variables Doehlert matrix for optimisation of an on-line pre-concentration system for zinc determination in natural water samples by flame atomic absorption spectrometry (2003) Microchem J, 75, pp. 211-221Long, G.L., Winefordner, J.D., Limit of detection (1983) Anal Chem, 55, pp. 712-715Yamini, Y., Tamaddon, A., Solid-phase extraction and spectrophotometric determination of trace amounts of copper in water samples (1999) Talanta, 49, pp. 119-124de Moraes, S.V.M., Brasil, J.L., Milcharek, C.D., Martins, L.C., Laranjo, M.T., Gallas, M.R., Use of 1,3-diaminepropane-3-propyl grafted onto a silica gel as a sorbent for flow-injection spectrophotometric determination of copper (II) in digests of biological materials and natural waters (2005) Spectro. Chim. Acta A, 62, pp. 398-406Castilho, E., Cortina, J.L., Beltrán, J.-L., Prat, M.-D., Granados, M., Simultaneous determination of Cd(II), Cu(II) and Pb(II) in surface waters by solid phase extraction and flow injection analysis with spectrophotometric detection (2001) Analyst, 126, pp. 1149-1153Lee, T., Choi, H., Determination and preconcentration of Cu(II) after adsorption of its cupferron onto benzophenone (2002) Bull Korean Chem Soc, 23, pp. 861-864(2005), CONAMA. National Council of Environment. Resolution number 357