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Register a new userChoose the optimum conditions for the simultaneous determination of Lead and Cadmium Using Graphite Mercury Film Electrode (GMFE) by voltammetry
اختيار الشروط المثلى للتحديد المتزامن لعنصري الرصاص والكادميوم باستخدام مسرى الغرافيت المغطى بفيلم من الزئبق (GMFE) بالطريقة الفولط أمبيرومترية
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تناول هذا البحث دراسة تأثير أهم الشروط التحليلية والتقنية في المنحنيات الفولط أمبيرومترية للرصاص والكادميوم , وذلك من أجل اختيار الشروط المثلى للتحديد المتزامن لهذين العنصرين بالطريقة الفولط أمبيرومترية التراكمية الأنودية النبضية التفاضلية DPASV , باستخدام مسرى الغرافيت المغطى بفيلم من الزئبق GMFE بصفة مسرى عامل . أظهرت النتائج أن الشروط التحليلية المثلى كانت عند استخدام إلكتروليت خلات الصوديوم – حمض الخل بتركيز 0.05M , حيث pH= 4.6, وتركيز قدره 25mg/l من Hg2+ , ونسبة CCd:CPb حتى 1:10 وبالعكس, أما بالنسبة للشروط التقنية المثلى فكانت بتطبيق مجال مسح كموني من -1200mV إلى -100mV عند كمون تراكم Eacc= -1200mV وزمن تراكم tacc= 120sec, وسرعة مسح 120mV/sec, وسعة نبضة 50mV . أعطت الشروط السابقة عند تطبيقها منحنيات فولط أمبيرومترية مثاليةIp(Cd)= 6.134µA , Ip(Pb)= 4.966µA,Ep(Cd)= -647mV , Ep(Pb)= -473mV. طبقت الشروط السابقة على عيّنة قياسية وتم الوصول إلى حدّ كشف قدره 0.100µg/l (Cd) , 1.000µg/l (Pb) , ومعامل الاسترجاع 100.5% =(Cd)R% و= 97.2%(Pb)R% , والانحراف المعياري 0.020mg/l =(Cd)SD و0.021mg/l =(Pb)SD, وهذا يدل على مدى صحة الطريقة ودقتها. درست صلاحية الطريقة بشروطها الجديدة على عدد من العينات البيئية فأبدت نجاحاً وكفاءة عالية.
This research studying the effect of the most important analytical and technical conditions on the voltammetric curves of lead and cadmium in order to choose the optimal conditions for the simultaneous determination of these two elements by Differential pulse anodic stripping voltammetry (DPASV) using Graphite mercury film electrode(GMFE) as a working electrode. The results showed that the optimum analytical conditions were when using Sodium acetate - acetic acid (0.05M) electrolyte, where pH= 4.6, and a concentration (25mg/l) of Hg2+, CCd:CPb ratio up to 1:10 and conversely, and the optimum technical conditions were when applying scanning field from -1200 to -100mV, accumulation potential Eacc= -1200mV, accumulation time tacc= 120sec, speed rate υ= 120mV/sec, and amplitude pulse ΔE= 50mV. The previous conditions gave ideal voltammetric curves, Ip(Cd)= 6.134µA, Ip(Pb)= 4.966µA, Ep(Cd) = -647 mV, Ep(Pb)= -473 mV. The previous conditions were applied on a standard sample and the limit of detection was (Cd) 0.100µg/l, (Pb) 1.000µg/l, retrieval coefficient R%(Cd)= 100.5%, R%(Pb)= 97.2%, standard deviation SD(Cd)= 0.020mg/l, SD(Pb)= 0.021mg/l; Therefore, that shows the accuracy and precision of the method. The validity of the method under its new conditions was examined on a number of environmental samples and showed success and high efficiency.
References used
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MAHMOOD, A.; MALIK, R.M., Human health risk assessment of heavy metals via consumption of contaminated vegetables collected from different irrigation sources in Lahore, Pakistan. Arabian Journal of Chemistry, 7, Pakistan, (2014), 91–99
KOJUNCU, Y.; BUNDALEVSKA, J.M.; AY, U.; CUNDEVA, K.; STAFILOV, T.; AKCIN, K., Atomic Absorption Spectrometry Determination of Cd, Cu, Fe, Ni, Pb, Zn,and Tl Traces in Seawater Following Flotation Separation. Separation science and technology, Vol. 39, Turkey, (2004), 2751–2765
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The study investigated the possibility of removing heavy metal ions (Cd, Pb) from
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waste available in abundance especially in the Syrian coast as well as easy to
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accurawcy. The results showed that the optimum adsorption conditions were at pH = 5 ,
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The method applied its selected terms to realistic samples of processed and industrial
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The glassy carbon electrode has been used as working electrode,
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stripping voltammetric method (ASV) in acidic media HCl. We
found that The reason for the absence of analytical signal
s
expressed on flow any electrodic process due to reduction
mechanism of Se(IV) on glassy carbon electrode from Se4+to Se2-
and formation H2Se.
This research aims to study the effect of certain analytical conditions to determine the arsenic in aqueous media using a Potentiometric, and then choose and adopt the optimum conditions for this determinism.
We studied the effect of each of the (PH
value, type, concentration puffer, effect of crippling electrolytes) to determine the arsenic in aqueous media and calibration using a standard solution of iodine. We also worked on raising the sensitivity of the method detection limit access to the ppm.
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Due to the absence of operational requirements and its unidentified solutions ,this
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d
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analytical conditions shows that the best response which give the Nernst slope of the
electrode had been obtained by adding 0.5ml of ammonium sulfate (3mol / l), and the
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10-5mol/l or less than that, it was necessary to soak the electrode in solution which has low
concentration for at least one hour, and diluted the taken volumes ten times . These
technical and analytical conditions was applied on standard solutions and environmental
samples(water), which showed the accuracy ,correctly and authenticity of the
measurements.
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