Separation and Micro Determination of Magnesium in Different Environmental and Vital Sample. Shawket. K.Jawad Fatima .A.Wannas AL-Ghurabi Kufa University. College of education for girls. Abstract 1-(2- Pyridyl azo)-4-Benzene naphthol(PABN) used as Spectrophotometric reagent for determination micro amount of Magnesium(II) in different Environmental and Vital samples, after conversion magnesium cation to anion complex by reaction with oxine, the study show 0.5M NaOH need to prepare oxine anion with concentration of 0.8M,initialy the organic reagent(PABN) must be - react with Nickel(II) to form large cation complex produce ion pair complex with Mg(ox)3 have maximum absorbance at λ=398nm, the study also include organic solvent effect, thermodynamic, stoichiometry, as well micro amount determination of Magnesium(II) in different samples. الخلصة استعمل الكاشف العضوي Pyridyl azo)-4-Benzene naphthol(PABN -2)-1) ككاشف طيفي لتقدير الكميات المايكروئية من المغنسيوم(II) في نماذج حياتية وبيئية مختلفة. بعد تحويل ايون المغنسيوم(II) إلى معقد ايوني سالب من خلل التفاعل مع الوكسين. وقد بينت الدراسة إن (0.5M) من هيدروكسيد الصوديوم (NaOH) هي الوسط الملئم لتحضير المعقد اليوني السالب للمغنسيوم من خلل تفاعل) 0.8M) للوكسين مع ايونات المغنسيوم ( II ). وقد تضمنت الدراسة كخطوة اولى تفاعل الكاشف الطيفي - (PABN) مع النيكل(II) لتكوين معقد ايون موجب كبير يقوم باستخلص المعقد اليوني السالب Mg(ox)3 على هئية معقد ترابط ايوني والذي أعطى قيمة امتصاص ملحوظة عند الطول الموجي λ=398nm . كما شملت الدراسة تأثير المذيب العضوي وتحديد تركيب المعقد المستخلص والجانب الثرموديناميكي لعملية الستخلص.وأخيرا استعمل الكاشف الطيفي (PABN) في تقدير المغنسيوم Mg(II) في مجموعة من النماذج المختلفة. Introduction Magnesium has been shown to be one of the most important and comman elements in our environment. It plays a critical role in photosynthesis as it is metal center in chlorophyll, is the activor of more than 300 enzymes, is critical to glycolysis. Magnesium is also one of the most abundant elements in erath ,s crust and the oceans. Two simple, sensitive and economical Spectrophotometric methods have been developed for the determination esomeprazole magnesium in commercial dosage forms. Method A is band on the reaction of esomeprazole magnesium with 5- sulfosalicylic acid in methanol to form a yellow product, which absorbs maximally at 365nm. Method B utilizes the reaction of esomeprazole magnesium with N-bromo succinmide in acetone- chloroform medium to from α-bromo derivation of the drug pealing at 380nm[1]. Magnesium is extracted with a chloroform solution of N-P- tolyle-2-thenohydroxy acid (PTTHA) form aqueous solution of pH=9.5. Mg-PTTHA complex is colorless and the color is developed by adding quinalizarin into the extract λMax=590nm[2]. Different Spectrophotometric methods for determination of Magnesium have been reported in many journals as simple, sensitive and economical methods[3-10]. This paper describe rapid, simple, sensitive and economical Spectrophotometric method for determination of magnesium(II), after conversion magnesium to anion complex with oxine by use Azo derivative to giving ion pair complex. Experimental All spectrophotometric measurements and absorbance were registered by using a double beam (UV-Vis) spectrophotometer shimadz UV 1700 ( Japan) and a Single beam (UV-Vis) spectrophotometer TRIUP international corp. TRUV 745 ( Italy), PH-meter WTW-INOLAB made in Germany, pye unican SP3-2001 Infrared
224 spectrophotometer (England), HY-4-Vibrator with AD Jurt about speed multiple use age function, E-Germany Electric Balance-Sattorns median.
Materials and solution All materials pure received from commercial sources and used as received with out any additional putrefaction. 1×10-2M organic reagent solution PABN prepared by dissolved 0.0325gm in 10 mL chloroform, other working solution prepared by dilution with chloroform, (1mg/mL )Mg(II) prepared by dissolved 0.6075gm of MgCl2-6H2O in 25mL distilled water contain 1mL conc. HCl,0.2M 8-Hydroxy quinoline prepared by dissolved 3.14gm in 100 mL chloroform. Procedure 5ml of 1×10-4M PABN dissolved in chloroform shaking for 15minutes with 5ml aqueous phase contain 50 μg Ni(II) at pH=8, at last separate aqueous solution from organic solution.5ml of 0.8M 8-Hydroxy quinoline dissolved in chloroform shaking with 5ml aqueous solution contain 50 μg Mg(II) and 0.5M NaOH for(7 min) separate organic phase from aqueous phase at later mixing organic phase in step(1) to organic phase of step(2) and measure the absorbance of ion pair complex formed at λ=398nm. Results and discstion Limitation wave length for maximum absorbance complex extracted λMax. taken 5ml of 1×10-4M PABN dissolved in chloroform[11], shaking with 5ml aqueous solution contain 50 μg Ni(II) at pH=8, this the first step, to prepare cation complex + - [Ni(PABN)m] , second step for prepare oxine anion complex of Mg(II) [Mg(ox)3] by taken 5ml (0.8M) 8-Hydroxy quinoline dissolved in chloroform , shaking with 5ml aqueous solution contain 50 μg Mg(II) and 0.5M NaOH for(5 min), after ward organic phase of step(1) Mixed with organic phase of step(2) to from ion pair complex + - [Ni(PABN)m] [Mg(ox)3] , the spectrum of this ion pair complex against organic). eagent solution in Fig(1) show wave length for maximum absorbance was(λMax =398
A
225 Journal of Babylon University/Pure and Applied Sciences/ No.(2)/ Vol.(21): 213
B Fig (1):UV-Vis spectra for(A): PABN(1×10-4M) & B: Magnesium(II) complex + - with [Ni(PABN)m] [Mg(ox)3]
Calibration Curve for Mg(II) in aqueous phase To deferent conc.Mg(II) in 5ml aqueous phase added ERichrom-B as spectrophotometric reagent and determine absorbance of complex formed at (λMax= 570 ) afterward polt absorbance vis. μg Mg(II) to obtain Calibration Curve in Fig(2). [12]
0.35 0.3 ) A
( 0.25
e c
n 0.2 a b
r 0.15 o s
b 0.1 A 0.05 0 0 10 20 30 40 50 microgram of Mg ion/5 mL
Fig (2)Calibration Curve for Mg(II) in aqueous phase Effect of NaOH Concentration Extracted Mg(II) as in general produce by used aqueous solution contain 50 μg Mg(II) with different concentration of NaOH(0.05-1M) shaking with 5ml (0.8M) 8- Hydroxy quinoline dissolved in chloroform after mixed organic phase contain - + Mg(ox)3 with organic phase contain [Ni(PABN)m] , measure the absorbance of each organic solution at (λMax =398), and polt absorbance vis. concentration of NaOH get Fig(3)
226
1.6 1.5 ) A (
e 1.4 c n
a 1.3 b r
o 1.2 s b
A 1.1 1 0 0.5 1 1.5 M oler conc. of NaOH
Fig (3) Effect of NaOH Concentration
The result show absorbance of ion pair complex extracted increase direct with concentration of NaOH increase to reach maximum and stable absorbance at 0.5M NaOH and more that is mean reaction reached the best equilibrium for high stable and high formation constant of ion pair complex. Effect of 8-Hydroxy quinoline Concentration Extraction experiment of Mg(II) according to general procedure, with different 8- Hydroxy quinoline concentration, after measure the absorbance of ion pair complex extracted at (λMax =398), polt absorbance value against 8-Hydroxy quinoline concentration get Fig(4).
2 )
A 1.5 ( e c a
n 1 a b r o s
b 0.5 A 0 0 0.5 1 1.5 Molar conc.of oxine
Fig (4) Effect of8-Hydroxy quinoline Concentration The result show absorbance of ion pair complex formed in organic solvent increase direct with increase of 8-Hydroxy quinoline concentration to reach maximum - absorbance at 0.8M and more because at this concentration anion complex [Mg(ox)3] reached to high formation stability which contribute to increase ion pair complex stability and formation.
Effect of Shaking Time 5ml of 1×10-4M organic reagent PABN dissolved in chloroform. Shaked with 5ml aqueous phase contain 50 μg Ni(II) at pH=8,for (15min) also 5ml of 0.8M 8-Hydroxy quinoline dissolved in chloroform and 0.5M NaOH Shaked with 5ml aqueous phase contain 50 μg Mg(II) for different time(2-15)minute, at later mixed for organic reagent PABN with , organic phase 8-Hydroxy quinoline and measure the absorbance of (λMax =398nm), against reagent solution as blank, afterward polt absorbance value against shaking time get Fig(5).
227 Journal of Babylon University/Pure and Applied Sciences/ No.(2)/ Vol.(21): 213
1.6
1.5 ) A ( 1.4 e c n
a 1.3 b r
o 1.2 s b
A 1.1
1 0 5 10 15 20 Time(min)
Fig (5) Effect of Shaking Time
The result appear (7)minute shaking time was the best to formation anion complex - magnesium[Mg(ox)3] and this shaking time increase formation equilibrium and stability anion complex as well as increase absorbance of complex, shaking time less than (7)minute not available for complex formation, so shaking for more than (7)minute which affect to increase the rate of dissociation and decline the absorbance of complex, which is mean decrease in ion pair complex formation and stability. effect of Organic Solvent 5ml of organic reagent 1×10-4M PABN dissolved in different organic solvent shaking with 5ml aqueous phase contain 50 μg Ni(II) at pH=8,for (15min) to from +2 [Ni(PABN)m] in organic solvent, as well5ml of 0.8M 8-Hydroxy quinoline dissolved in the same organic solvent shaking with 5ml aqueous phase contain 50 μg Mg(II) - 0.5M NaOH for (7)minute to for anion complex[Mg(ox)3] in organic solvent, at later + - mixed the two organic phase to from ion pair complex [Ni(PABN)m] [Mg(ox)3] ,and measure the absorbance at(λMax =398nm),against organic reagent in the same organic solvent, and we are obtained the results at Table(1).
Table(1) organic solvent effect
organic solvent dielectric Abs.at (λMax =398nm constant(ε) 1 Nitro benzene 35.740 0.630 2 50%Nitro benzene+50%Benzene 15.600 0.751 3 30% Nitro benzene+70%Benzene 10.650 0.450 4 Chloro benzene 5.708 0.550 5 Choroform 4.806 1.545 6 5%Nitro benzene+95%Benzene 3.400 0.830 7 Benzene 2.804 0.300 The result show maximum absorbance for ion pair complex formation was with chloroform, and the result don't show any linear relation between dielectric constants of organic solvents used and ion pair complex formation, but there is an effect for organic solvents structure on ion pair complex formation and stability which is either contoct ion pair or loose ion pair.
Stoichiometry
228 Used slope analysis method for limitation more probable structure of ion pair complex extracted, by extracted 50 μg Mg(II) according to general procedure by use different concentration of organic reagent PABN(1×10-6-1×10-3M) dissolved in chloroform, measure the absorbance of ion pair complex in organic phase at(λMax =398nm), against organic reagent solution as blank, get the result as in Fig(6).
2.2 ) 1.7 A ( e
c 1.2 n
a 0.7 b r
o 0.2 s
b -0.3 A -0.8 -5.5 -4.5 -3.5 -2.5 -1.5 -0.5 0.5 log[PABN]
Fig(6).effect of organic reagent concentration on absorbancen ion pair complex
Also determine remainder quantity of Mg(II) in aqueous phase by Spectrophotometric methods .Eriochrome blank method[12] and returning to Calibration curve Fig(2), at later determine transferred quantity of Mg(II) to organic phase to form ion pair complex and calculate distribution ratio(D) at each conctration of organic reagent PABN, and get the result as in Fig(7)
1.9 Slope=0.8 1.4 0.9 )
D 0.4 ( g
o -0.1 l -0.6 -1.1 -1.6 -10 -5 0 log[PABN]
Fig(7) slope analysis method
The results demonstrate more probable structure of ion pair complex in organic + - phase extracted was (1:1). [Ni(PABN)m] [Mg(ox)3] ,as in Fig(8)
229 Journal of Babylon University/Pure and Applied Sciences/ No.(2)/ Vol.(21): 213
- Mg(ox)3
Effect of Temperature Because solvent extraction is thermodynamic method for extraction and for statement temperature effect on extraction of Mg(II), applicated general method for extraction at different temperature(275-303K) afterword measure the absorbance of ion pair complex in organic phase at(λMax =398nm),as in Fig(9),as well as determine remainder quantity of Mg(II) in aqueous phase by Spectrophotometric methods. Eriochrome blank method[12], and transferred quantity to organic phase, at later calculate distribution ratio(D) and extraction constant(Kex) at each temperature
D Kex ... [canion]aq [ligand]org
From the slope of straight line in Fig (10) enthalpy ∆Hex was determined by the realation:
Hex Solpe 2.303R Free energy of extraction ∆Gex and entropy ∆Sex were calculated according to as in relation below :
Gex RTLnKex
Gex H ex TSex
2 ) A
( 1.5
e c a
n 1 b r o
s 0.5 b A 0 270 280 290 300 310 Temp K
Fig(9) effect of Temperature of absorption of ion pair complex
230
SLOP E=3.5 9 8 x e K
7 g o l 6 5 -3.8 -3.6 -3.4 -3.2 -3 Temp.1/K K
Fig (10) : Temperature effect on extraction constant Kex The result show extraction equilibrium of Mg(II) as ion pair complex was endothermic and thermodynamic data of extraction was -1 -1 - -1 ΔHex=0.0075K. J. mol , ΔGex=-46.6K.J.mol ,ΔSex=149J.K mol
Anion effect - Extracted Mg(II) as [Mg(ox)3] according to general procedure as ion pair + - complex [Ni(PABN)m] [Mg(ox)3] ,in precence of some other anions. Absorbance of ion pair complex extracted at (λMax =398nm), get the result at Table(2)
Table(2):Effect of anion on absorption of ion pair complex
anion Abs.at (λMax =398nm -2 1 C2O4 1.785 -2 2 CrO4 1.783 3 Trartarat 1.774 - 4 MnO4 1.901 -2 5 ClO3 1.822
The results show enhancement the absorption of ion pair complex extracted at - presence of these anions which is more hydrophilic than Mg(ox)3 which increase ionic strength of solution, also these hydrophilic anion destroy the hydration shell of - Mg(II) and increase complexation reaction for formation of anion complex Mg(ox)3 and increase of ion pair complex stability and formation . Calibration curve of complex formation 5ml aqueous solution contain different quantity of Mg(II) (5-50 μg) and 0.5M NaOH shaking with 5ml (0.8M) 8-Hydroxy quinoline, organic phase mixed with + organic phase contain cation complex [Ni(PABN)m] prepare as in general procedure afterword measure the absorbance at (λMax =398) for each Mg concentration afterward polt absorbance values vs. μg Mg(II) get straight line relation as in Fig(11).
231 Journal of Babylon University/Pure and Applied Sciences/ No.(2)/ Vol.(21): 213
2.1
1
8.0
6.0
4.0 A b
2.0s o r b
a 0 n c
e 0 01 02 03 04 05
)
A gMgµ /5lm (
Fig(11) Effect of μgMg(II) on absorbance of ion pair complex extracted to organic phase
Application Determination Magnesium(II) in different samples according to general procedure detailed previously.
Table(3) Magnesium content in agricultural soil Samples ppm Mg 1 AL-Abbasia-1-farm 310 2 AL-Abbasia-2-orahard 260 3 AL-Kufa- agricultural area 450 4 Nurscry-1 350 5 Nurscry-2 540 6 Nurscry-3 445 7 AL-Hurria 330 8 AL-Mushkhab 360 9 AL-Manadira 355 y 2 y 3 a a - r 2 r - f a r - 2 i b - a i ) c u d 1 c r s a s - y a K s 1 i n - r a r - - r o a h 500 1 A d a L b c - i u s M i u ( s s a A b r u s N a r e N n A r - b u L o c M u
b 400 - A H A n N M - L - - L L a A L A
A 300 A b r o
200 s b
100 A 0 1 2 3 4 5 6 7 8 9 10 ppm
Fig (12)Magnesium(II) content in agricultural soil
Table(4) Magnesium(II) content in non- agricultural soil Sample ppm Mg
232 1 Twenty revolt square 180 2 Najaf-kufa street 130 3 AL-Muthanna street 220 4 AL-Hira 370
t - t e a a l a e r f r L i e o n a u 400 r A v n t u k H e s - - a q r f
s h L a t y
j 300 t A u a n e
M N Absorbanc
w 200
T e(A) 100
0 1 2 3 4 ppm
Fig (13)Magnesium content in non-agricultural soil
Table(5):Agricultural crop
Sample ppmMg 1 Potato 410 2 Pepper 260 3 Tomato 320 4 Eggplant 358 5 Banana 355 a t n n a o o a n t t l r a a a p e t B g
m o 500 p g o P p E T e 400 P 300 Absorbance(A) 200 100 0 1 2 3 4 5 ppm
Fig(14):Magnesium quantity in Agricultural crop
Table(6)Water content of Mg Sample ppmMg 1 Irrigation water 65
233 Journal of Babylon University/Pure and Applied Sciences/ No.(2)/ Vol.(21): 213
2 Refuse irrigation 130 water 3 Drinking water 58 4 RO-Water(in home) 55 5 Native RO-Water 45 6 Imparted RO-Water 54
e s u
f
- r e
) r e R O t g n n e e - i t a R n o
( 30 i i O m a r t d k W o R e w a t e n h t 25 i g e a r i
r Absorbace v r i a r t W D 20 p I -
a (A) m O N
I 15 R 10 5 0 1 2 3 4 5 6 ppm
Fig(15) Water content of Magnesium ( Mg)
All the results was identical to quantity measured in previous studies, where international measurements show soil content is 13.4%, 1.3g/L in water of seas and oceans less in rivers as well as 300-500ppm in agricultural crop, all the results show abandunt quantity of magnesium in all sample less than optimum abandunt, as well as increase in magnesium may be effect on crowth of plants and crops quality and may be effect on the general healthy. Referents Nafisur Rahman, Zchra Bano and Syed Najmul Hejaz Azmi, Journel of Chinese chemical society 55,557-566(2008) Dallali, Nasser; Agnawal,. Iron. J. chem. & chem. Eng. 23(1),65-71(2008). Scot,; Dunn,C.J.; Mallarlay,; Sharpe, M. Durgs, 151,456(2007). Behed,R. ; Mohsin. Haz. Mat 54,1511(2007). Rahman,; Rahman,;Azmi,..chin chim. Soc. 54,185(2007). Rahmam,. ; Siddigui,. ; Azmi,. ,.Chin. chim. Soc. 53,735(2006) Li,. ;Yany, ,.Chin. chim. Soc 52,383(2006). Raz,A. ;Ausrari,; Rahman,. ,.Chin. chim. Soc. 52,1055(2005). EL-Wasseef,; Eid, M. ;Belal,.Chin. chim. Soc. 52,507(2005). Guelu,K. ; Sozgen. ;. ; Ozyurelek,M. ; Apak,. ,Talanta, 65,1226(2005). .Fatema.A.Wannas. M.Sc thesis of collage of education for girls kufa university(2010). Z.Marczenko (spectrophotometric determination of elements )All is tlorwoord limited (1986)
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