Nitrilo triasetik asit uç gruplu poliakrilamidin eser element analizinde kullanımı
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Fen Bilimleri Enstitüsü
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Bu çalışmada bakır (II)» krom (III), mangan (II), çinko (II) metallerinin» Nitrilotriasetikasit (MTA) üç grüplu poliakrilamid kullanarak» ayırma Ve önzenginleştirilmesi ile Grafit Fırınlı Atomik Absorpsiyon Spektrofotometresinde (GFAAS) tayinleri incelenmiştir. BU amaçla Cu(II), Cr(III)» Mri(II), Zn(İI)*nin çalkalama ve kolon yöntemleriyle NTA üç gruplü ı poliakrilamid üzerinde alıkonması ve geri kazanılması incelenmiştir. Elementlerin alıkonması ve geri j kazanılması için en uygun deneysel koşullar. [ belirlendikten sonra> gerçek Örneklerde en çok ] bulunan matriks olan MâCl varlığihda çalışarak bu ] elementlerin Önzenginleştirilmesi Ve girişime. nedeh ' olan bileşenlerden ayrılması sağlanmış ve Grafit ; Fırınlı Atomik Absorpsiyon Spektrofotometresinde - tayinleri yapılmıştır.
The concentration of many trace elements in different media are below the detection limit. In addition» because of the matrix interferences, it ia hardly possible to obtain the true concentrations. In the determination of trace elements, the use of separation and preconcentratioh technique is a necessity when the concentration of the ahalyte is too low to be determined directly as weli aş interferences due to matrix can not be eliminated. Various analytical techniques, such as extract ion > ion Exchange, coprecipitation etc. With numerous1 tnetarials haVe been widely applied for this purpose * Polymers having chelating groups are recommended as the appropriate collectors for the preconcentration and separation of ahalyte elements prior to their determination by instrumental methods. The properties of the different resins have been investigated with respect to recoveries at different pM values* the choice of appropriate eluent, the rate of retention and elution, capacity, the case of the preconcentratioh and separation procedure, reproducibility, blank values and the effect of different matrices on recoveries. In this study, the synthesis of polyacrylamid having Nitriiotriaceticacid (NTA) groups and its Sorption properties for the preconcentration of Cu(IIh Cr(III), Mn(IIh ahd Zn(IÎ) prior to their determination by Graphite Furnace Atotoic Absorption Spectophotometry (GFAAS) is described. For thiâ purpose, the retention percent of the elements and recovery of the retained elements at different experimental conditions Were investigated by Using batch and column methods. By this means, ultra-trace V Özet Bu çalışmada bakır (II)» krom (III), mangan (II), çinko (II) metallerinin» Nitrilotriasetikasit (MTA) üç grüplu poliakrilamid kullanarak» ayırma Ve önzenginleştirilmesi ile Grafit Fırınlı Atomik Absorpsiyon Spektrofotometresinde (GFAAS) tayinleri incelenmiştir. BU amaçla Cu(II), Cr(III)» Mri(II), Zn(İI)*nin çalkalama ve kolon yöntemleriyle NTA üç gruplü ı poliakrilamid üzerinde alıkonması ve geri kazanılması incelenmiştir. Elementlerin alıkonması ve geri j kazanılması için en uygun deneysel koşullar. [ belirlendikten sonra> gerçek Örneklerde en çok ] bulunan matriks olan MâCl varlığında çalışarak bu ] elementlerin Önzenginleştirilmesi Ve girişime. neden ' olan bileşenlerden ayrılması sağlanmış ve Grafit ; Fırınlı Atomik Absorpsiyon Spektrofotometresinde - tayinleri yapılmıştır. ıV- nRS03~H+ 4- Mn+ «.... l- (RSO3~)nMn+ -l- nH+ nRC02~Hf + Mnl j * (RC02-)nMrı+ + nHf (2) where Mn+ and RC02~H"f represent metal ion and ion exchange resin, respectively [1]. in the pr«paration of the polyacrylamide modified with NTA; Acrylamide, Nitrilotriaceticacid, Cerlum Sulphate, Sulphurid acid which were ali Merck reagent grade chemicals were used. Polymerization was carriöd out at 55°C in the presence of air in a two-necked round bottomed flask equipped with a stirrer. The polymerizatlon reaction Was studied at 0.03 mol/L ceriüm sulphate^ 0.02 mol/L MTA^ 0.2 mol/L acrylamid^ 0.75 mol/L sulphuric acid cohcentrations. After an öne hour shakihg* the polymers v;ere precipitated in about 10 vol. of acetone for the removal of any resiudal monomer and initiator and then drled in vacuum at 25°C. The resin was ground to a partide size in the range between 50 and 60 mesh sieve. in the synthesis of polyacrylamide modified with NTA> the mechanism of initiation and propagation steps may be represented as follows [2]; R K R H+ J l R- M -f Ce(IV) j «. R-.N-CH2 4 » CH2 Ce(IV) XC^=0 C=O ^^^0 l o" R Kd R ı ^ / R-^tt f » R-M + Ce(III) (3) u/ \ , \ M CH2 -C02 -H4" CH2 Ce(IV) C =0 ~z£&~ ' ^^^0 vıı R ki R l l R-N-ÇH2 + CH2=CH t R-N-CH2-CH2-CH (4) C=0 OO l l HH2 NH2 (R=CH2-COOH) Chemical bonds (as coordlnation bonds) between metal ions and O ör M atoms on the polymer may be formed as follows [3J; -CH2-CH-CH2-CH-CH2-CH~ O, C=0 C=0 C II / \ NH2.NH2 O CH2 ^ M ör M- N-CHo ^ \ / f NH? NHp O CHo 1^1^ \ / c=o oo c ı ı n -CH2-CH-CH2-CH-CH2-CH- O in the experimental study; both batch and column methods wete used. in batch method* the effects of pHj shaking time and retention of Cu(II), Cr(III)^ Zn(II) and Mn(II) were investigated. For this pürpose» pH of the mixture containing 10 mi of sample solution (0.2 mg/L Cu(II), Cr(III)*Mn(II)and 3 mg/L Zn(II)) and O.lg of resin was adjusted to preselected value with 0.1 mole/L Hd ör HaOH in a polyethylene Ydssel.The mixhm:e wa3 shaken f ör l to 60 tnin. Using a shaker and the concentration of analytes on the supernetant vere deterınined by GFAAŞ. The analytes were eluted f rom the resin by 10 mi 2 M HCl and determined by GFAAS. The maximum loading capâcity of the resin was determined using the batch procedure as well 0.1 g of resin was dispefsed in 10 mi 100 mg/L CU(II) solution. The pM of solution was adjusted to 6 at which maxlmum retention is reached. After shaking' f ör 60 min-i Cu(II) conce,ntration in the supernatânt was determined vııı in colutnn procedure the effect of MaCl on the recovery was investigated. A small polyethylene colurnn with a porous frih v/as filled with the sugpension of 0.1 g.of resin. The pH of the sample solution cohtain (0.2 mg/L Cu(II), Cr(III),Mn(II)and 3,0 mg/L Zn(II)) in the presence of %0> 5 NaCl was adjusted to 6. The sample was passed through the column, then the elements collected on the resin vere eluted with 10 mi 2 M HC1 and determined by GFAAS. The elements studied were quantitatively (>%90) retaihed on the resin in the pH range of 4.5 to 7. The optimum working pH was chosen as 6 for the ali other procedures. The elements collected were eluted quantitatively after treating the loaded resin with 2M HC1. The contact time between sample solution and resin for the completatlon of the quantitative retention as well as between eluent and loaded resin for the quantitative elution were less than öne ttıinute. The elements studied weire also determined,in the presence of sodiumchloride which was present as the majör matrix in many samples (sea water>serum ete*) and causes severe intefferences.. A quantitative separation could be succesfully achieved in the samples containing even %0,5 NaCl as the matrix. As a result, it can be concluded that polyacrylamide containing nitrilotriaceticacid groups is an appropriated collector for the preconcentration and separâtion of Cu(II), Cr(III)»Mn(II)ahd Zn(II) prior to their determination by GFAAS because of its high capacity, very fast iretention and elution rate.for quantitative recovery^ free of interferertce. in the presence of high NaCl concentrations and quite good reproducibility.
The concentration of many trace elements in different media are below the detection limit. In addition» because of the matrix interferences, it ia hardly possible to obtain the true concentrations. In the determination of trace elements, the use of separation and preconcentratioh technique is a necessity when the concentration of the ahalyte is too low to be determined directly as weli aş interferences due to matrix can not be eliminated. Various analytical techniques, such as extract ion > ion Exchange, coprecipitation etc. With numerous1 tnetarials haVe been widely applied for this purpose * Polymers having chelating groups are recommended as the appropriate collectors for the preconcentration and separation of ahalyte elements prior to their determination by instrumental methods. The properties of the different resins have been investigated with respect to recoveries at different pM values* the choice of appropriate eluent, the rate of retention and elution, capacity, the case of the preconcentratioh and separation procedure, reproducibility, blank values and the effect of different matrices on recoveries. In this study, the synthesis of polyacrylamid having Nitriiotriaceticacid (NTA) groups and its Sorption properties for the preconcentration of Cu(IIh Cr(III), Mn(IIh ahd Zn(IÎ) prior to their determination by Graphite Furnace Atotoic Absorption Spectophotometry (GFAAS) is described. For thiâ purpose, the retention percent of the elements and recovery of the retained elements at different experimental conditions Were investigated by Using batch and column methods. By this means, ultra-trace V Özet Bu çalışmada bakır (II)» krom (III), mangan (II), çinko (II) metallerinin» Nitrilotriasetikasit (MTA) üç grüplu poliakrilamid kullanarak» ayırma Ve önzenginleştirilmesi ile Grafit Fırınlı Atomik Absorpsiyon Spektrofotometresinde (GFAAS) tayinleri incelenmiştir. BU amaçla Cu(II), Cr(III)» Mri(II), Zn(İI)*nin çalkalama ve kolon yöntemleriyle NTA üç gruplü ı poliakrilamid üzerinde alıkonması ve geri kazanılması incelenmiştir. Elementlerin alıkonması ve geri j kazanılması için en uygun deneysel koşullar. [ belirlendikten sonra> gerçek Örneklerde en çok ] bulunan matriks olan MâCl varlığında çalışarak bu ] elementlerin Önzenginleştirilmesi Ve girişime. neden ' olan bileşenlerden ayrılması sağlanmış ve Grafit ; Fırınlı Atomik Absorpsiyon Spektrofotometresinde - tayinleri yapılmıştır. ıV- nRS03~H+ 4- Mn+ «.... l- (RSO3~)nMn+ -l- nH+ nRC02~Hf + Mnl j * (RC02-)nMrı+ + nHf (2) where Mn+ and RC02~H"f represent metal ion and ion exchange resin, respectively [1]. in the pr«paration of the polyacrylamide modified with NTA; Acrylamide, Nitrilotriaceticacid, Cerlum Sulphate, Sulphurid acid which were ali Merck reagent grade chemicals were used. Polymerization was carriöd out at 55°C in the presence of air in a two-necked round bottomed flask equipped with a stirrer. The polymerizatlon reaction Was studied at 0.03 mol/L ceriüm sulphate^ 0.02 mol/L MTA^ 0.2 mol/L acrylamid^ 0.75 mol/L sulphuric acid cohcentrations. After an öne hour shakihg* the polymers v;ere precipitated in about 10 vol. of acetone for the removal of any resiudal monomer and initiator and then drled in vacuum at 25°C. The resin was ground to a partide size in the range between 50 and 60 mesh sieve. in the synthesis of polyacrylamide modified with NTA> the mechanism of initiation and propagation steps may be represented as follows [2]; R K R H+ J l R- M -f Ce(IV) j «. R-.N-CH2 4 » CH2 Ce(IV) XC^=0 C=O ^^^0 l o" R Kd R ı ^ / R-^tt f » R-M + Ce(III) (3) u/ \ , \ M CH2 -C02 -H4" CH2 Ce(IV) C =0 ~z£&~ ' ^^^0 vıı R ki R l l R-N-ÇH2 + CH2=CH t R-N-CH2-CH2-CH (4) C=0 OO l l HH2 NH2 (R=CH2-COOH) Chemical bonds (as coordlnation bonds) between metal ions and O ör M atoms on the polymer may be formed as follows [3J; -CH2-CH-CH2-CH-CH2-CH~ O, C=0 C=0 C II / \ NH2.NH2 O CH2 ^ M ör M- N-CHo ^ \ / f NH? NHp O CHo 1^1^ \ / c=o oo c ı ı n -CH2-CH-CH2-CH-CH2-CH- O in the experimental study; both batch and column methods wete used. in batch method* the effects of pHj shaking time and retention of Cu(II), Cr(III)^ Zn(II) and Mn(II) were investigated. For this pürpose» pH of the mixture containing 10 mi of sample solution (0.2 mg/L Cu(II), Cr(III)*Mn(II)and 3 mg/L Zn(II)) and O.lg of resin was adjusted to preselected value with 0.1 mole/L Hd ör HaOH in a polyethylene Ydssel.The mixhm:e wa3 shaken f ör l to 60 tnin. Using a shaker and the concentration of analytes on the supernetant vere deterınined by GFAAŞ. The analytes were eluted f rom the resin by 10 mi 2 M HCl and determined by GFAAS. The maximum loading capâcity of the resin was determined using the batch procedure as well 0.1 g of resin was dispefsed in 10 mi 100 mg/L CU(II) solution. The pM of solution was adjusted to 6 at which maxlmum retention is reached. After shaking' f ör 60 min-i Cu(II) conce,ntration in the supernatânt was determined vııı in colutnn procedure the effect of MaCl on the recovery was investigated. A small polyethylene colurnn with a porous frih v/as filled with the sugpension of 0.1 g.of resin. The pH of the sample solution cohtain (0.2 mg/L Cu(II), Cr(III),Mn(II)and 3,0 mg/L Zn(II)) in the presence of %0> 5 NaCl was adjusted to 6. The sample was passed through the column, then the elements collected on the resin vere eluted with 10 mi 2 M HC1 and determined by GFAAS. The elements studied were quantitatively (>%90) retaihed on the resin in the pH range of 4.5 to 7. The optimum working pH was chosen as 6 for the ali other procedures. The elements collected were eluted quantitatively after treating the loaded resin with 2M HC1. The contact time between sample solution and resin for the completatlon of the quantitative retention as well as between eluent and loaded resin for the quantitative elution were less than öne ttıinute. The elements studied weire also determined,in the presence of sodiumchloride which was present as the majör matrix in many samples (sea water>serum ete*) and causes severe intefferences.. A quantitative separation could be succesfully achieved in the samples containing even %0,5 NaCl as the matrix. As a result, it can be concluded that polyacrylamide containing nitrilotriaceticacid groups is an appropriated collector for the preconcentration and separâtion of Cu(II), Cr(III)»Mn(II)ahd Zn(II) prior to their determination by GFAAS because of its high capacity, very fast iretention and elution rate.for quantitative recovery^ free of interferertce. in the presence of high NaCl concentrations and quite good reproducibility.
Açıklama
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1995
Konusu
Asitler, Eser elementler, Poliakrilamid, Acids, Trace elements, Polyacrylamide