Simultaneous determination of nickel and copper by H-point standard addition method-first-order derivative spectrophotometry in plant samples after separation and preconcentration on modified natural clinoptilolite as a new sorbent.
For the simultaneous determination of nickel(ll) and copper(ll) in plant samples, a rapid and accurate method was developed. In this method, solid-phase extraction (SPE) and first-order derivative spectrophotometry (FDS) are combined, and the result is coupled with the H-point standard addition method (HPSAM). Compared with normal spectrophotometry, derivative spectrophotometry offers the advantages of increased selectivity and sensitivity. As there is no need for carrying out any pretreatment of the sample, the spectrophotometry method is easy, but because of a high detection limit, it is not so practical. In order to decrease the detection limit, it is suggested to combine spectrophotometry with a preconcentration method such as SPE. In the present work, after separation and preconcentration of Ni(ll) and Cu(ll) on modified clinoptilolite zeolite that is loaded with 2-[1-(2-hydroxy-5-sulforphenyl)-3-phenyl-5-formaza-no]-benzoic acid monosodium salt (zincon) as a selective chromogenic reagent, FDS-HPSAM, which is a simple and selective spectrophotometric method, has been applied for simultaneous determination of these ions. With optimum conditions, the detection limit in original solutions is 0.7 and 0.5 ng/mL, respectively, for nickel and copper. The linear concentration ranges in the proposed method for nickel and copper ions in original solutions are 1.1 to 3.0 x 10(3) and 0.9 to 2.0 x 10(3) ng/mL, respectively. The recommended procedure is applied to successful determination of Cu(ll) and Ni(ll) in standard and real samples.
Shahid Bahonar University of Kerman, Department of Chemistry, PO Box 76175-133, Kerman, Iran.
Rasool
R
Roohparvar
Mohammad Ali
MA
Taher
Alireza
A
Mohadesi
D000327:Adsorption; D001391:Azo Compounds; D002863:Chromogenic Compounds; D031250:Clethraceae / Q000737:chemistry / Q000633:toxicity; D003300:Copper / Q000032:analysis* / Q000592:standards / Q000633:toxicity; D005562:Formazans; D019015:Geologic Sediments / Q000032:analysis; D009532:Nickel / Q000032:analysis* / Q000592:standards / Q000633:toxicity; D010944:Plants / Q000737:chemistry* / Q000633:toxicity; D012015:Reference Standards; D052616:Solid Phase Extraction / Q000379:methods; D013053:Spectrophotometry / Q000379:methods* / Q000592:standards; D017641:Zeolites
D001391:Azo Compounds; D002863:Chromogenic Compounds; D005562:Formazans; C083175:clinoptilolite; D017641:Zeolites; C009809:2-carboxy-2'-hydroxy-5'-sulfoformazylbenzene; D003300:Copper; D009532:Nickel