title: Application of cotton as a solid phase extraction sorbent for on-line preconcentration of copper in water samples prior to inductively coupled plasma optical emission spectrometry determination.
abstract: Copper, as a heavy metal, is toxic for many biological systems. Thus, the determination of trace amounts of copper in environmental samples is of great importance. In the present work, a new method was developed for the determination of trace amounts of copper in water samples. The method is based on the formation of ternary Cu(II)-CAS-CTAB ion-pair and adsorption of it into a mini-column packed with cotton prior applying inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental parameters that affected the extraction efficiency of the method such as pH, flow rate and volume of the sample solution, concentration of chromazurol S (CAS) and cethyltrimethylammonium bromide (CTAB) as well as type and concentration of eluent were investigated and optimized. The ion-pair (Cu(II)-CAS-CTAB) was quantitatively retained on the cotton under the optimum conditions, then eluted completely using a solution of 25% (v/v) 1-propanol in 0.5 mol L(-1) HNO(3) and directly introduced into the nebulizer of the ICP-OES. The detection limit (DL) of the method for copper was 40 ng L(-1) (V(sample)=100mL) and the relative standard deviation (R.S.D.) for the determination of copper at 10 microg L(-1) level was found to be 1.3%. The method was successfully applied to determine the trace amounts of copper in tap water, deep well water, seawater and two different mineral waters, and suitable recoveries were obtained (92-106%).
authors.affiliation: Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Faraji
authors.forename: Yadollah
authors.initials: Y
authors.lastname: Yamini
authors.forename: Shahab
authors.initials: S
authors.lastname: Shariati
mesh_terms: D000327:Adsorption; D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D003300:Copper / Q000032:analysis*; D032561:Cotton Fiber; D005618:Fresh Water / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates; D012623:Seawater / Q000032:analysis; D052616:Solid Phase Extraction / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002593:Cetrimonium Compounds; D062385:Hydroxybenzoates; D014874:Water Pollutants, Chemical; C015076:chrome azurol S; D003300:Copper; D000077286:Cetrimonium