ANALYTICAL STUDIES ON CHROMATOGRAPHIC SEPARATION AND DETERMINATION OF SOME ORGANIC AND INORGANIC COMPOUNDS

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1 Umm Al-Qura University Faculty of Applied Science Chemistry Department ANALYTICAL STUDIES ON CHROMATOGRAPHIC SEPARATION AND DETERMINATION OF SOME ORGANIC AND INORGANIC COMPOUNDS by Gharam Ibrahim Mohammed Abolkair (B.Sc.in Chemistry) A Thesis Submitted in partial Fulfillment of the Requirements of The Master Degree of Science(Analytical Chemistry) SUPERVISORS Dr/ Shaker.J. Azhari Associate. Prof. of Analytical Chemistry Chemistry Department Faculty of Applied Science Umm Al-Qura University Prof/ Mohamed.M. El-Defrawy Professor of Analytical Chemistry Chemistry Department Faculty of Applied Science Umm Al-Qura University

2 جامعة أم القرى كلية العلوم التطبيقية قسم الكيمياء دراسات تحليلية للفصل الكروماتوجرافي وتقدير بعض المركبات العضوية وغير العضوية رسالة مقدمة من غرام إبراهيم محمد ابوالخير بكالوريوس علوم في الكيمياء كجزء من المتطلبات للحصول على درجة الماجستير في العلوم)كيمياء تحليلية( المشرفون الدكتور/ شاكر جميل أزهري أستاذ الكيمياء التحليلية المشارك كلية العلوم التطبيقية - قسم الكيمياء األستاذ الدكتور/ محمد محمد الدفراوي أستاذ الكيمياء التحليلية كلية العلوم التطبيقية - قسم الكيمياء

3 1-1- NON SUPPRESSED ION CHROMATOGRAPHY METHOD TO SEPARATE AND DETERMINATE : : INORGANIC ANIONS: A very large number of inorganic anions have been separated successfully by ion chromatography (IC ) with non-suppressed conductivity detector (CDD). There are many applications in these context,e.g. determination of inorganic anions in honey. The chemical composition of honey has been treated for along time. The determination of anions has not been described for honey, perhaps due to the problem associated with great matrix influence,mainly in the oxalate analysis. Determination of organic acids in honey usually oxalic acid does not apear (1,2) probably due to its lower retention. Recently, a method for determinated oxalate in honey by ion exclusion chromatography with mass spectrometry (MS) detection has been proposed (3),the same technique but with ion trap detection was used to determine phosphoric acid in honey (4). Obviously a lot of options have been proposed to evaluate those anions in many different matrixes, among them the most used are capillary electrophoresis and IC. To isolate the anions solid-phase 12

4 extraction on anionic cartridges has been selected, the best conditions to make the extraction and the elution have been proposed by Nozal et al (5). The authors used a mixture of lithium borate-gluconate ( 2% ), n-butanol ( 2% ), acetonitrile (ACN) ( 12% ) and water( 84.6% ) as eluent to separate and determine anions, such as, ( nitrate, phosphate, sulfate and oxalate ) in honey and honeydew samples on a column,(150x4.6 mm i.d.) ICpak A-HC from waters packed with 10µM particles. These anions were separated within 50 min with limit of detection ( LOD ) between µg/g. IC has been recognized to be very useful approach for the determination of inorganic anions in several kinds of environmental sample (6,7,8). Because of the capacity of several columns to operate without suppressor column devices simpliftes equipment requirements and enhance case of use compared to suppressed IC. Single column ion chromatography ( SCIC ) (9) was used to separate and determine inorganic anions in drainage water and soil solution. A low conductivity eluent M sodium borate M gluconate in ( 12% ) ACN ( v/v ) were used to separate anions,such as,(cl, NO 2,NO 3,HPO 4,SO 2 4 ) on column packed with polymethacrylate resin with a quaternary ammonium functional group with sep- aration time of 10 min and the LOD were mg/l. The result of anions separation were compared with those 15

5 obtained by tradit-ional methods. This method had the advantage of being a rapid and sensitive. A number of alternative methods have been reported in the literature,all of which use analytical separator column without suppressor. These methods differ from each other in the mode of det-ection employed. Compared to non-chromatography technique,ic has the advantages of separation before detection, increase sensitivity,simple sample preparation and faster analysis time (10,11). Bolance et al (12) improved performance characteristic of this method by using optimization of chromatographic parameters (eluent flow rate,mobile phase composition) in order to be applied to the routine analysis of drinking water. The authors separated and determined six inorganic anions, such as,(f, Cl, NO 2, Br, NO 3, SO 2 4 ) in drinking water by using 1.8mmol/L phthalic acid (H 2 ph), 2 amino-2-hydroxymethyl-1,3 propendiol and 8.1 mmol/l ACN as eluent with CDD. The separation column was a metrohm IC anion column super sep(100x4.6mm i.d.) packed with polymerth-acrylate with quaternary ammonium group. The separation time was 8 min with LOD of mg/l. The detection sensitivity for analyte ions depends on the detection system,the eluent composition(acid or salt) and their elution position relative to the second system peak. In previous study (13), 0.2mM 1,2-dihydroxybenzoic-3,5-disulfonic acid was 16

6 used as an eluent for the separation of inorganic anions. Since sulfate ion,one of the important common anions,eluted on the front shoulder of the second system peak,its determination was difficult. It is necessary to select some other compound that can elute sulfate ion faster than the second system peak. Also,since the acid eluents have high background conductivity in comparison with the neutralized eluents,the signals from the detector cannot be amplified electrically as sensitively as in supperssed IC. So that, A non-suppressed IC system for the high sensitivity detection of anions,such as,(phosphate,chloride,bromide,nitrate and sulfate )was developed using 0.5mM 5-sulfoiso phthalic acid as eluent (14).The separation was achieved on separator column (250x 4.6 mm.i.d) in 10min with LOD between 2.1x10 8-4x 1 8 M. The detection sensi-tive was ten time higher than that using conventional non supperssed IC with sodium phthalate as eluent and was almost the same as the using conventional suppressed IC with carbonate- hydrog-encarbonate as eluent under the same electrical condition with a CDD. There was overlapped between the peak of nitrite and chloride ions.the separation of these ions will be improved by using another stationary phase of different selectivity in the ion exchang reaction : ORGANIC ACIDS : Organic acids are very important because they can provide 11

7 ARABIC SUMMARY 412

8 الملخص العربي تشتتتما الاراستتة علتتى جزجتتة أجتتزاء. الجتتزء ال ل يشتتتما علتتى تريقتتة تحليليتتة بستتيطة ع ا لي تت ة ا لح س ا س تتية ل لو ص تتا ل لتق تت اير ا ن تتي ل س تتت ة م تتن النيون تت ات ا لةي تتر ع تتوي ة ا لت ا لي تتة )الولوريا الكلوريا البر ميا النيترات اليوديا الستتتتتتلوات( باستتتتتتتقاام تقنيتتتتتتة اليتتتتتتو كر متتتاتوجرافي الةيتتتر متتتانو لقتتتا تتتتم طنجتتتام وتتتاس الطريقتتتة المطتتتور باستتتتقاام تتتورمتحرك مكتتو متتن 4.4mM متتن ضمتتف الوكاليتتو مقلتتو متتن 4.1mM متتن التترس)ويار كستي ميكيتا (أمينتو ميكتا 0.2mM+ متن N- {[)ايكيتا أمينتو(جايوكستو ميكيا]ويارامينو كاربونيا ميكيا}تراي ميكيا امنيوم كلوريا) ETHTC ( الهتا متن واا العما وو تطوير تريقة ذات مزايا معينة للتقاير ا ني لألنيونات الةير ع وية فتي بع تتف ا لنب ات تت ات ا لطبي تتة بو ا س تتطة تقني تتة الي تتو كر م تت اتوجر ا في ا لةي تتر م تت انو ب ا س تتتقا ام اإلجراءات التي تزيا من فعالية النظام ذلو من أجا تطبيقها على التحاليا الر تينية. لقتا تميتزت الطريقتة المقترضتة بعتا مزايتا وامتة مكتا الحساستية العاليتة قصتر قت التحليا كميات صةير للتحليا تحايا ضا د الكشف للتقاير ذلو في مستوى الجزء متن المليو عز على التطبيق الواسو. لقا تم تطبيق و تا س ا لطريق تة بنج ت ال ع ل تى ف ص تا تق ت اير و تا س النيون ت ات ا ل س تتة ف تي بع تف النباتتتات الطبيتتة التتتي تنمتتو فتتي أمتتاكن مقتلوتتة متتن المملكتتة العربيتتة الستتعودية مكتتا النعناع الحبو الا ش العطر. 415

9 اما الجزء الكاني فيحتوي على تريقة مقترضة لوصا تقاير الضماض الع توية التاليتة )ضمتتتف الوورميتتتو ضمف السيتستتتو ضمف اإلستتتكوربيو ضمف السكستتتنيو ضمف الزكتيتتتو ضمف الستتتتريو ضمف الطرتريتتتو ضمف ال كستتتاليو( باستتتتقاام تقنيتتتة اليتتتو كر متتتاتوجرافي الةيتتتر متتتانو لقتتتا تتتتم طستتتتقاام وتتتاس الطريقتتتة باستتتتقاام تورمتحرك يحتوي على 4.25mM من ضمف الوكاليو مقلتو متن 4.35mM متن التترس)ويار كستي ميكيتا (أمينتو ميكتا 0.2mM+ متن N- {[)ايكيتا أمينتو(جايوكستو ميكيا]ويارامينو كاربونيا ميكيا}تراي ميكيا امنيوم كلوريا) ETHTC (. ا له ا م تن و ت ا ا ا لعم تا و تو تط توير تريق ت ة ذ ا ت مز اي ت ا معين تة ل لتق تاير ا ن تي ل ألضم ت اض الع وية باستقاام تقنية اليو كر ماتوجرافي الةير مانو ذلو للتحاليا الر تينية. لق تتا تمي تتزت ا لطريق تتة بع تتا مز اي تت ا مك تتا ق ص تتر ق تت ا لتح ليا ا س تتتقا ام كميتتات صتتةير تح اي ت تا ض ت تا د ا لك ش ت ت ف ذ ل ت تو ف ت تي م س ت ت توى ا لج ت تزء م ت تن ا لم لي ت ت و عز ع ل ت تى ا لتطبي ت ت ق الواستو مما عتزم مزايتا وتاس الطريقتة المصتااقية الاقة القطية ضا د الكشتف تحايتا الكمية المستقامة للتقاير. لقتا تتم تطبيتق الطريقتة المقترضتة بنجتال علتى فصتا تقتاير الضمتاض الع توية فتي بعف النباتات الطبية مكا النعناع الحبو الا ش العطر. أم ا ا لجز ء ا لك ا ل ث فيحتو ي ع لى ت أ س تي تريق ت ة س تريع ة ض س ا س تة ل لو ص تا ل لتق ت اير ا ن تي لتتبعف النيونتتات الةيتتر الع تتوية الضمتتاض الع تتوية )ضمتتف السيتستتو ضمتتف السكستتتنيو الولوريتتتا ضمتتتف الزكتيتتتو ضمتتتف الستتتكوربيو ضمتتتف الوورميتتتو 416

10 الكلوريتتتتتا البر ميتتتتتا النيترات ضمف السترستتتتتو ضمتتتتتف الطرتريتتتتتو ضمتتتتتف ال كستاليو الستلوات اليوديتتا( باستتقاام تقنيتة اليتتو كر متاتوجرافي الةيتر متتانو. لقتا تتم طنجتام الطريقتة المقترضتة باستتقاام تتورمتحرك يحتتوي علتى 4.4mM متن ضمتتف الوكاليتتو مقلتتو متتن 4.1mM متتن التتترس)ويار كستتي ميكيتتا (أمينتتو ميكتتا 0.2Mm+ من N- {[)ايكيا أمينتو(جايوكستو ميكيتا]ويتارامينو كاربونيتا ميكيتا}تتراي ميكيا امنيوم كلوريا) ETHTC (. لقتا أرهترت الاراستة المتاى القطتي الواستو للعزقتة متا بتين مستاضة التار تركيتز اليو في م س تتو ى ا لج تز ء م تن ا لم ليو لق ت ا ت تم تطبي تق و ت ا س ا لطريق تة بنج ت ال ع ل تى ف ص تا تقتاير النيوتتات الةيتر ع توية الضمتاض الع توية الموجتود فتي بعتف النباتتات الطبية مكا ا لنعن اع ا لحبو ا ل ا ش ا لعط تر ا لت تي تنم تو ف تي من ت اتق مقت لو تة م تن ا لمم لك تة العريبة السعودية. 411

11 SUMMARY This study consists of three main sections. The first involves: A sensitive and simple analytical method for simultaneous separation and determination of common six inorganic anions, fluoride, chloride, bromide,nitrate, iodide and sulfate was developed by non suppressed ion chromatography. The separation was achieved with mobile phase consisting of 2.2 mm phthalic acid,2.7 mm tris (hydroxymethyl) aminomethane and 0.2 mm N-{[( (ethylamino) thioxomethyl] hydrazinocarbonylmethyl} trimethyl ammonium chloride (ETHTC). The aim of this work to improve and characterize the method for simultaneous determination of six inorganic anions in medicinal plants by non suppressed ion chromatography, using optimization procedures, in order to applied to the routine analysis. The proposed method has numerous advantages over the other widely used non suppressed ion chromatography methods, higher sensitivity, shorter analysis time,lower quantization and detection limits. The performance characteristics parameters : precision, accuracy,linearity and detection limits. Also, the proposed method was successfully applied for the separation and determination of some inorganic anions from some medicinal plants including : mentha vridis, mentha longifolia, origanum majorana and cymbopogon winterianus which are existing in different places at kingdom of Saudi Arabia. 6

12 The second involves : a non suppressed ion chromatogramphy for the determination of some organic acids is proposed. Eight organic acids including,formic,acetic,ascorbic,succinic,lactic,citric,tartaric and oxalic acids were separated and identified. The separation was achieved with mobile phase consisting of 2.45mM phthalic acid,2.35 mm tris (hydroxymethyl) aminomethane and 0.2 mm N-{[( (ethylamino) thioxomethyl] hydrazinocarbonylmethyl} trimethyl ammonium chloride (ETHTC). The purpose of this work is to improve and characterize the simultaneous determination of organic acids by non suppressed ion chromatography to routine analysis. The proposed method has numerous advantages over the other widely used :shorter analysis time,lower quantization and detection limits. The performance characteristics of the method were established by determining the following validation parameters:precision,accuracy,linearity, detection and quantization limits. Also, the proposed method was successfully applied for the separation and determination of some organic acids from some medicinal plants including:mentha vridis,mentha longifolia,origanum majorana and cymbopogon winterianus. The third establishes a very rapid and sensitive method by using a non suppressed conductimetric detection ion chromatography for the simultaneous separation and determination of com- 1

13 mon organic acids and inorganic anions. The separation was performed with mobile phase consisting of 2.2 mm phthalic acid and aqueous mixture of 2.7 mm tris (hydroxymethyl) aminomethane and 0.2 mm N-{[( (ethylamino) thioxomethyl] hydrazinocarbonylmethyl} trimethyl ammonium chloride (ETHTC). The results revealed a wide range of linear relationship between peak area and ion concentration in ppm. The method is successfully applied for the analysis of some medicinal plants grown in Kingdom of Saudi Arabia. All the four species of the medicinal plants are varied in concentration of organic acids and inorganic anions. 8

14 CONTENTS Page CHAPTER 1: INTRODUCTION 1-1 Non suppressed ion chromatography method Inorganic anions Organic acids i The role of using eluent in organic acid separation Mixture of inorganic acids and inorganic anions Suppressed ion chromatography method Inorganic anions i Method for improving detection limits ii Effect of efficiency on resolution iii Optimization of chromatographic method Organic acids Mixture of inorganic anions and organic acids 34 CHAPTER 2 : HPLC INSTRUMENTATION 2-1 INTRODUCTION 2-2 HPLC equipments Pumps Mobile phase reservoirs Proportioning valve Sample injector system Solvent degassing procedure Line filters Column

15 2-2-8 Guard column Column thermostats Detectors Data systems Pressure measurement 55 CHAPTER 3 : EXPERMENTAL 3-1 Materials and method Preparation of ligand Chemicals Stock solution i Inorganic anions ii Organic acids Preparation of content of mobile phase i- The eluent for the separation of inorganic anions ii The eluent for the separation of organic acids iii The eluent for the separation of organic acids and inorganic 60 anions Equipments i Ion chromatography system ii ph meter iii Conductivity detector iv Micropipet Sample preparation i For the analysis of inorganic anions ii For the analysis of organic acids iii For the analysis of mixture of 62 11

16 organic acids and inorganic anions Optimum conditions i Optimum condition for the separation of Inorganic anions ii Optimum condition for the separation of Organic acids iii Optimum condition for the separation of inorganic anions 64 and organic acids CHAPTER 4 : RESULT AND DISCUSSION 4-1 Separation and determination of inorganic anions Effect of phthalic acid concentration The effect of flow rate on the retention time The effect of eluent ph on the retention behaviour of 71 inorganic anions The effect of column temperature and eluent 74 strength on the retention time The effect of ETHTC on retention time tr and sensitivity Application Separation and determination of organic acids Effect of phthalic acid concentration The effect of flow rate on the retention time The effect of eluent ph on the

17 retention behaviour of organic acids The effect of column temperature and eluent strength 110 on the retention time The effect of ETHTC on retention time tr and sensitivity Application Separation and determination of inorganic anions and organic acids Effect of phthalic acid concentration The effect of flow rate on the retention time The effect of eluent ph on the retention behaviour of inorganic anions and organic 153 acids The effect of column temperature and eluent 156 strength on the retention time The effect of ETHTC on 163 retention time tr and sensitivity Analysis of medicinal plants 176 Conclusion References Arabic summary