Microsoft Word - 96-106 Chemistry | 96 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Spectrophotometric Determination of Cu(II) by Complex with Ethyl Cyano(2-Methyl Carboxylate Phenyl Azo Acetate) (ECA) Elham Nghaimesh Mezaal Kawther Ahmad Sadiq Asmaa Nihad Zaki Rasmia Mahmood Rumez Dept. of Chemistry/ College of Education for Pure Sciences (Ibn-Al- Haitham)/ University of Baghdad Received in:24/February/2016,Accepted in:11/May/2016 Abstract A new simple and sensitive spectrophotometric method for the determination of trace amount of Cu(II) in the ethanol solution have been developed. The method is based on the complexation of Cu(II) with ethyl cyano(2-methyl carboxylate phenyl azo acetate) (ECA) in basic medium of sodium hydroxide givining maximum absorbance at (λmax = 521 nm). Beer's law is obeyed over the concentration range (5-50) (μg / ml) with molar absorptivity of (3.1773 × 102 L mol-1 cm-1) and correlation coefficient (0.9989). The optimum conditions for the determination of Cu(II)-complex and have been studied and applied to determine Cu(II) in synthetic water sample using simple and standard addition methods. Keywords: Spectrophotometric, determination, copper, complex. Chemistry | 97 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Introduction Copper has Cu symbol, atomic number 29 and atomic mass 63.54 gm mol-1. Copper is a reddish metal with a face centered cubic crystalline structure[1,2]. It is one of the several metals that play an important role in the biological systems, it occurs naturally which in many vegetables, meat and grains [3,4]. Copper is a mineral that nowadays possess few problems. It is widely distributed, as a component of various enzymes in foodstuffs of all kinds, at levels between 1 and 5 ppm. Milk is notably low in copper, at a round 2 ppm and mammalian liver is exceptionally high, at a round 80 ppm. The daily in take in normal adult diets is between 1 and 3 mg [5]. Methods for determination of copper were studied spectrophotometric in synthetic mixture and water samples[6], natural waters and pharmaceutical samples with chloro(pheny) glyoxime[7], determination of micro amount of copper(II) in different environmental and vital samples by new organic reagent[8], determination of micrograms of copper(II) and platinum(II)[9], complexation of cefixime with copper(II) using acetate NaOH buffer in water:methanol[10], determination of copper(II) using 5-nitrosalicyldehyde semicarbazone (NSS) as an analytical reagent[11], with 2-hydroxy-1-naphthalene carboxaldehyde phenyl hydrozone as an analytical reagent[12]. Synthesis of the ligand ethyl cyano(2-methyl carboxylate phenyl azo acetate) (ECA) and the structure of (ECA) in Figure (1) [13]. In this work a sensitive and simple method for the determination of trace amounts of Cu(II) by UV-Vis spectrophotometry was described based on the formation of the Cu(II)- ECA complex and the influences of some parameters. Experimental Apparatus - UV-Vis spectrophotometer A shimadzu double beam UV-Vis spectrophotometer model UV-1601 (Kyoto, Japan) working at wavelength of 190-1100 nm. -Digital balance Digital analytical-Sartorius (Bp 3015-Germany). Reagents Copper chloride Fluka AG Buchs SG. Sodium hydroxide Fluka AG Buchs SG. Hydrochloride acid Riedel-Dehaen AG. Ethyl cyano(2-methyl carboxylate phenyl azo acetate) (ligand) (1000 μg / ml) The ligand was prepared as same in paper [13]. A stock solution of (1000 μg / ml) of ligand was prepared by dissolving (0.1 gm) in ethanol absolute and then made up to (100 ml) in a volumetric flask and was kept ambient bottle a way from sun light. Copper(II) (1000 μg / ml) A stock solution of (1000 μg / ml) of Cu(II) was prepared by dissolving (0.2682 gm) of copper chloride dihydrate (CuCl2.2H2O) in ethanol absolute and diluted to (100 ml) in a volumetric flask by absolute ethanol. Working solution of (500 μg / ml) was prepared by simple dilution of stock solution with ethanol absolute. Chemistry | 98 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Sodium hydroxide ≈ (0.1 M) This solution was prepared by dissolving (0.4 gm) of sodium hydroxide in ethanol absolute and diluted to (100 ml) in a volumetric flask by the same solvent. Hydrochloric acid ≈ (0.1 M) This solution was prepared by diluting of (1.54 ml) of concentrated hydrochloric acid (37%) and diluted to (250 ml) in a volumetric flask by ethanol absolute. Results and discussion Absorption spectra The complex is produced from the reaction between (0.5 ml) of Cu(II) (500 μg / ml) with (0.5 ml) of ligand (1000 μg / ml) in a volumetric flask (5 ml) and diluted to ethanol absolute giving maximum absorbance at λmax = 521 nm an in Figure (2). Optimum conditions for regulation reaction There are many parameters affecting on the complexation reaction and absorbance of complex which is produced. Effect of ligand volume When a various volumes of ligand solution (0.05, 0.1, 0.15, …..0.6) ml for (1000 μg / ml) were added to (0.5 ml) of (500 (μg / ml) Cu(II), solution was found that (0.5 ml) of ligand is enough to give a maximum absorption and was considered to be optimum for concentration range of (5-50) (μg / ml) of Cu(II). The results were shown in Table (1). Effect of hydrochloric acid volume Existence of hydrochloric acid (0.1-1) ml of (0.1 M) in reaction solution effect on decreasing the intensity of absorbance for produced complex. The results were shown in Table (2). Effect of sodium hydroxide volume It was found that the presence of base in reaction solution effect on increasing the intensity of absorbance for the produced complex, NaOH was selected and (0.1 ml) of (0.1 M) was found to be the optimum volume. This base gives high sensitivity which was selected in subsequent experiments the results were shown in Table (3). Effect of order of addition To obtain optimum results, the order of addition of base should be the first followed by addition of ligand and Cu(II). The results were shown in Table (4). Effect of temperature The resulting complex of the proposed method was studied at room temperature (25 ˚C), the absorbance values remain constant. The results were shown in Table (5). Effect of time on the complex formation The results show that the complex produced was stable between (5-60) minutes, the absorbance value was stable. The results were shown in Table (6). Chemistry | 99 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Calibration graph The content of series of (5 ml) calibration flasks containing (0.1 ml) of (0.1 M) NaOH and (0.5 ml) of ligand (1000 μg / ml) with different concentrations (5-50) (μg / ml) of Cu(II) (500 μg / ml) were diluted with ethanol absolute. The absorption spectra were recorded against blank at temperature 25 ˚C. A linear calibration graph for Cu(II)-complex is obtained (Figure 3), which shows that Beer's law is obeyed. Precision and accuracy Under the optimum condition, the precision and accuracy of the method was calculated. The results were shown in Table (7). Structure of the complex The stoichciometry of the complex between Cu(II) and ligand was investigated using Job's method and mole ratio method; the results show that 1:2 Cu(II) to ligand complex was formed. The formation of the complex produced suggest occurring as follows, Figure (4)[14]. Effect of interference elements We have studied the effect of interference elements (Zn(II), Na(I), K(I), Mg(II), Ca(II)), on the complexation of Cu(II). A stock solution of each element (10000 μg / ml) was prepared by dissolving (2.0845 gm) ZnCl2, (2.5421 gm) NaCl, (1.9067 gm) KCl, (2.7691 gm) CaCl2 and (3.9173 gm) MgCl2 in ethanol absolute and then made up to (100 ml) in volumetric flask with the same solvent working solution of (1000, 500, 50) μg / ml of each element was prepared by simple dilution for primary stock solution (10000 μg / ml) in a volumetric flask (5 ml) which contains (0.1 ml) NaOH, (0.1 M), (0.5 ml) ligand (1000 μg / ml) and (0.5 ml) Cu(II) (500 μg / ml) diluted up to the mark with ethanol absolute. Taken absorbance of each solution in (λmax = 521 nm) against blank. The results showed that interference elements are not affected on to determination of Cu(II) as ECA complex, Table (9). Application Two methods were successfully applied, (simple method and standard addition method) for determination of Cu(II) in synthetic a river water. The sample Cu(II) in synthetic a river water (1000 μg / ml) was prepared by taking (0.2682 gm) of CuCl2.2H2O dissolving in a river water and transferred in a volumetric flask (100 ml) diluted up to the mark with same solvent. Simple method transferred (0.25 ml) of Cu(II) in synthetic a river water (1000 μg / ml) to a volumetric flask (5 ml) contains (0.1 ml) NaOH (0.1 M) and (0.5 ml) ligand (1000 μg / ml) diluted up to mark with ethanol absolute. Taken absorbance of solution in (λmax = 521 nm) against blank. The results were shown in Table (10). Standard addition method transferred (0.25 ml) of Cu(II) in synthetic a river water (1000 μg / ml) to each volumetric flask (5 ml) contains (0.1 ml) NaOH (0.1 M) and (0.5 ml) ligand (1000 μg / ml) and various concentrations of Cu(II) solution (5-50) μg / ml diluted up to the mark with ethanol. Taken absorbance of each solution in (λmax = 521 nm) against blank. The results were shown in Figure (5) and Table (10). Conclusion A new simple and sensitive spectrophotometric method for the determination of trace amount of Cu(II) in the ethanol solution. The method is based on the complexation of Cu(II) with ethyl cyano(2-methyl carboxylate phenyl azo acetate) (ECA). Chemistry | 100 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 References 1. Lim and Zinkle, S.J. (2012) “Physical and mechanical properties of copper and copper alloys”, Comprehensive Nuclear Materials, 4, Elsevier, Amsterdam, 667-690. 2. Zaki, A.N. (2015) “Spectrophotometric determination of copper ion by direct method and indirect cloud point using the amino acid methionine”, M. Sc. Thesis, College of Education for Pure Sciences -Ibn-Al- Haitham, University of Baghdad. 3. Smith, W.F. and Javad, H. (2003) “Foundations of materials science and engineering”, MC Graw-Hill professional, 223. 4. Kavitha, C.; Babu, S.M. and Saraswathi, K. (2013) “Spectrophotometric determination of copper as copper piperazine”, International Letters of Chemistry, Physics and Astronomy, 8 (3): 205-209. 5. Coultate, TP. Food (1996) “The chemistry of its components”, the Science park: Cambridge; 314. 6. Fullah, L.; Sharma, S.;Rahman, N.; Najmul, S.;Iqbal, B., Ismail, M. and Al-Barwani, Z. (2010) “UV spectrophotometric determination of Cu(II) in synthetic mixture and water samples”, Journal of the Chinese Chemical Society, 57: 622-631. 7. Turkoglu, O. and Soylak, M. (2005) “Spectrophotometric determination of copper in natural waters and pharmaceutical samples with chloro(phenyl) glyoxime”, Journal of the Chinese Chemical Society, 52: 575-579. 8. Jawad, S.K.; Ali, S.K. and Hameed, S.M. (2011) “Spectrophotometric determination of micro amount of copper(II) in different environmental and vital samples by new organic reagent”, Iraqi National of Chemistry, 43: 299-309. 9. Taha, D.N.; Abdul Ridha, H.S.; Mohammed, H.S. and Hufdhi, R. (2012) “A rabid and sensitive spectrophotometric determination of copper(II) and platinium(II) of 5-[(4-hydroxy phenyl)azo]-4,6-dihydroxy-2-mercaptopyrmidine”, The First Scientific Conference the Collage of Education for Pure Sciences, 1: 294-302. 10. Ramadan, A. A., Manadil, H. and Dahha, M. (2013) “UV-Vis spectrophotometric study for determination of cefixime in pure from and in pharmaceuticals through complexation with Cu(II) using acetate NaOH buffer in water:methanol”, International Journal of Pharmacy and Pharmaceutical Sciences, 5 (1): 428-433. 11. Lokhande, R.S., Khadke, L., and Patankar Jain, K.N. (2014) “Liquid extraction and spectrophotometric determination of Cu(II) using 5-nitrosalicylaldehyde semicarbazone (NSS) as an analytical reagent”, Asian Journal of Research in Chemistry, 7 (11): 81-83. 12. Sonawane, R.P.; Lokhande, R.S. and Chavan, U.M. (2013) “Development of method for extraction spectrophotometric determination of Cu(II) with 2-hydroxy-1-naphthalene carboxaldehyde phenyl hydrozone as an analytical reagent”, International Letters of Chemistry Physic and Astronomy, 9 (1): 1-6. 13. Hassan, H. A. (2013) “Synthesis and characterization of some new 1,2,3-triazole, pyrazoline-5-one and thiazolidinone derivatives”, Journal of Al-Nahrain University, 16 (1): 53-59. 14. Sarhan, B. M.; Rumez, R. M. and Hassan, H. A. (2013) “Synthesis and characterization of some new metal complexes of ethyl cyano(2-methyl carboxylate phenyl azo acetate)”, Ibn Al-Haitham Journal for Pure and Applied Sciences, 26 (2): 178-187. Chemistry | 101 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Table (1) Effect of ligand volume of absorbance value of complex at temperature (22 ˚C) Vol. of ligand (ml) Absorbance 0.05 0.039 0.10 0.075 0.15 0.101 0.20 0.110 0.25 0.113 0.30 0.125 0.35 0.137 0.40 0.140 0.45 0.147 0.50 0.149 0.55 0.148 0.60 0.147 Table (2) Effect of hydrochloric acid volume on absorbance value of complex at temperature (20 ˚C) Vol. of hydrochloric acid (0.1M) (ml) Absorbance 0.0 0.145 0.1 0.103 0.2 0.101 0.3 0.098 0.4 0.090 0.5 0.088 0.6 0.086 0.7 0.085 0.8 0.083 0.9 0.075 1.0 0.070 Table (3) Effect of sodium hydroxide volume on absorbance value of complex at temperature (20 ˚C) Vol. of sodium hydroxide (0.1 M) (ml) Absorbance 0.0 0.145 0.1 0.219 0.2 0.199 0.3 0.198 0.4 0.196 0.5 0.193 0.6 0.187 0.7 0.184 0.8 0.180 0.9 0.175 1.0 0.170 Chemistry | 102 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Table (4) Effect of order of addition on absorbance value of complex at temperature (21 ˚C) Order of addition Absorbance Cu(II) + ligand + NaOH 0.220 Cu(II) + NaOH + ligand 0.201 Ligand + NaOH + Cu(II) 0.090 Ligand + Cu(II) + NaOH 0.100 NaOH + Ligand + Cu(II) 0.245 NaOH + Cu(II) + Ligand 0.180 Table (5) Effect of temperature on absorbance value of complex Temp. (˚C) Absorbance 20 0.240 25 0.251 30 0.245 35 0.221 40 0.200 45 0.187 Table (6) Effect of time on the complex formation at temperature (20 ˚C) Time (min.) Absorbance 0 0.238 5 0.241 10 0.242 15 0.241 20 0.242 25 0.242 30 0.241 40 0.242 50 0.241 60 0.242 Table (7) Precision and accuracy of the method Element Taken (μg / ml) Found (μg / ml) RE % RSD % n = 5 Recover % Cu(II) 05 05.0 0.000 0.00000 100.0 20 20.0 0.000 0.31494 100.0 50 50.2 -0.400 0.12577 100.4 Chemistry | 103 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Table (8) Method validation of the spectrophotometery determination of Cu(II) with ligand in ethanol absolute Parameter Value λmax (nm) 521 slope 0.0050 intercept 0.0000 R2 0.9980 r 0.9989 εmax (L mol -1 cm-1) 3.1773 × 102 sandell index (μg cm-2) 2.0000 × 102 Table (9) Effect of interference elements on the determination of Cu(II) as (ECA) complex Element of interference Conc. element interference (μg / ml) Found as Taken of Cu(II) (μg / ml) Found of Cu(II) (μg / ml) RE % Recover % Zn(II) 50 ZnCl2 50 49.8 0.040 99.6 500 50 50.0 0.000 100.0 1000 50 49.6 0.080 99.2 Na(I) 50 NaCl 50 50.0 0.000 100.0 500 50 49.6 0.800 99.2 1000 50 49.6 0.800 99.2 K(I) 50 KCl 50 50.2 -0.400 100.4 500 50 50.0 0.000 100.0 1000 50 50.0 0.000 100.0 Ca(II) 50 CaCl2 50 49.8 0.040 99.6 500 50 49.8 0.040 99.6 1000 50 49.6 0.080 99.2 Mg(II) 50 MgCl2 50 50.2 -0.400 100.4 500 50 49.6 0.800 99.2 1000 50 49.6 0.800 99.2 Table (10) Results for analysis of Cu(II) in a river water by two methods Element Method of analysis Taken (μg / ml) Found (μg / ml) Regression equation R2 r RE % Recover % RSD % n = 5 Cu(II) Simple method 50 50.2 y=0.0050x+0.0000 0.9980 0.9989 -0.400 100.4 0.12577 standard addition method 50 50.0 y=0.0050x+0.2500 0.9980 0.9989 0.000 100.0 0.00000 Chemistry | 104 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 COOCH3 N N CH C COOC2H5 N Figure (1) Structure of (ECA) Figure (2) Absorption spectra of (a) 50 (μg / ml) of Cu(II) (b) 100 (μg / ml) of ligand (c) 50 (μg / ml) of Cu(II) with 100 (μg / ml) of ligand against reagent blank Figure (3) Calibration graph of Cu(II)-complex y = 0.0050x + 0.0000 R² = 0.9980 r = 0.9989  0 0.05 0.1 0.15 0.2 0.25 0.3 0 10 20 30 40 50 60 A b so rb a n ce Conc. Cu(II) (μg / ml) Chemistry | 105 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 C N N CH OCH3O Cu Cl2 [Cu(ECA)2]Cl2 C N NCH O OCH3 C O OC2H5 C N N C O C2H5O C COOCH3 N N CH COOC2H5 NC CuCl2.2H2O + (ECA) 2 + 2H2O Figure (4) Suggest product formation pathway Figure (5) Results for analysis of Cu(II) in a river water by two methods y = 0.0050x + 0.0000 R² = 0.9980 y = 0.0050x + 0.2500 R² = 0.9980 ‐0.2 ‐0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 ‐70 ‐60 ‐50 ‐40 ‐30 ‐20 ‐10 0 10 20 30 40 50 60 A b so rb a n ce Conc. Cu(II) (μg / ml) Chemistry | 106 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 مثيل -2(اثيل سيانو التقدير الطيفي للنحاس الثنائي بوساطة تكوين معقد مع )كاربوكسليت فنيل ازو خالت الھام نغيمش مزعل أحمد صادقكوثر أسماء نھاد زكي رسمية محمود رميز قسم الكيمياء/ )ابن الھيثم (كلية التربية للعلوم الصرفة / جامعة بغداد 2016/أيار/11:،قبل في2016/شباط/22:استلم في الخالصة تعتمد . تم تطوير طريقة طيفية جديدة بسيطة وحساسة لتقدير كميات قليلة من النحاس الثنائي في المحلول الكحولي في وسط قاعدي من )مثيل كاربوكسليت فنيل ازو خالت -2(اثيل سيانو الطريقة على تكوين معقد بين النحاس الثنائي و وجد انه يطيع قانون بير ظمن ". نانوميترا 521عند الطول الموجي ھيدروكسيد الصوديوم الذي يعطي اعظم امتصاص ومعامل االرتباط 1- سم 1-لتر مول) 102 × 3.1773(مللتر وقيمة االمتصاصية الموالرية / مايكروغرام ) 50- 5(التراكيز تم دراسة الظروف المثلى لتقدير المعقد وطبقت الطريقة لتقدير النحاس في نموذج مصنع من الماء وباستعمال ). 0.9989( .الطريقة االعتيادية وطريقة اضافات القياس .طيفي، تقدير، نحاس، معقد :الكلمات المفتاحية