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Xylan is one of the major hemicelluloses present in plant cell wall matrix, where it is closely associated with other cell wall components, cellulose and lignin. Xylan has enormous potential as a renewable biopolymer and recently, research in the direction of isolation and utilization of xylan is gaining lot of research attention. Extraction of xylan from the plant cell walls involves the hydrolysis of xylan and its transfer from the plant cell wall matrix to the hydrolyzing media. Current process of extraction involves prolonged heating of the biomass with the hydrolysis media at high temperature and/or pressure that leads to molecular degradation of xylan and limits its high potential polymeric applications. In this research, microwave assisted alkaline extraction of polymeric xylan from birch wood is investigated as an alternative to the time intensive conventional extraction. The hypothesis to be tested is that the microwave’s selective heating ability leads to the generation of hot spots through its interaction with the alkali present in the fibers and the resulting "explosion effect" loosen the recalcitrant fiber structure network thereby facilitating the hydrolysis of xylan and its dissolution before undergoing significant degradation. Effect of microwave extraction on the yield of xylan and wood solubilization, physico-chemical properties of wood fibers and of isolated xylan were investigated in comparison with conventional extraction. Low power input microwave (110 W) alkaline extraction was found to be an efficient alternative to the conventional extraction. FTIR and chemical composition of wood fibers after extraction demonstrated an increased removal of xylan from the wood fibre using microwave extraction. SEM, X-ray microtomography, and X-ray crystallinity studies of wood fibers demonstrated a porous and loosened fibre structure after microwave extraction confirming the hypothesis. Molecular weight of the isolated xylan using microwave extraction was found to be higher compared to the xylan isolated using conventional extraction indicating less molecular degradation. About 75% of xylan present in birch wood could be extracted using a low power input microwave heating under optimized extraction conditions of 8wt% NaOH solution, 1:8 (g:mL) solid to liquid ratio, and 25 minutes of extraction time.

<p>U okviru doktorske disertacije razvijena je brza i selektivna metoda za<br />određivanje i praćenje ostataka herbicida na bazi sulfonilurea (nikosulfuron,<br />oksasulfuron, tribenuron metil, tritosulfuron, triasulfuron, rimsulfuron i<br />prosulfuron) u zemlji&scaron;tu primenom visoko pritisne tečne hromatografije sa<br />UV detektor sa nizom fotoosetljivih dioda (HPLC-UV-DAD). Razdvajanje<br />sulfonilurea je izvedeno uz primenu Zorbax Eclipse XDB-C18 kolone. U cilju<br />definisanja odgovarajućih uslova analize, ispitan je i definisan uticaj<br />najznačajnijih eksperimentalnih faktora. Usvojeni su sledeći optimalni uslovi<br />gradijentne elucije: mobilna faza acetonitril (A) i 0,1% sirćetna kiselina (B) t<br />= 0 min, 52% A; t = 2-2,5 min, 47% A; t = 2,5-5 min, 52% A, pri konstatnom<br />protoku od 1 mL min-1 i temperaturi kolone od 250C. Na osnovu odziva<br />analitičkog signala, njegove reproduktivnosti i linearnosti, talasna dužina od<br />240 nm je usvojena kao odgovarajuća. Utvrđeno je da je uticaj matriksa bio<br />izražen te je stoga za kvantitativno određivanje sadržaja SU u uzorcima<br />zemlji&scaron;ta primenom HPLC-UV-DAD metode kori&scaron;ćena MMC kalibraciona<br />kriva. Pri analizi ekstrakata nekontaminiranog zemlji&scaron;ta ostvarena je granica<br />kvantitativnog određivanja za nikosulfuron, oksasulfuron, tribenuron metil,<br />tritosulfuron, triasulfuron, rimsulfuron i prosulfuron od 3,16 &mu;g kg-1, 3,40 &mu;g<br />kg-1, 3,76 &mu;g kg-1, 4,13 &mu;g kg-1, 3,60 &mu;g kg-1, 3,04 &mu;g kg-1 i 2,97 &mu;g kg-1,<br />redom. Za potrebe osetljivijih, selektivnijih i tačnijih određivanja SU u<br />zemlji&scaron;tu, definisana je metoda uz primenu tečne hromatografije sa<br />tandemskom masenom spektrometrijom (HPLC-MS-MS). HPLC-MS-MS je<br />kori&scaron;ćena kao referntna tehnika za proveru rezultata koji su dobijeni<br />primenom HPLC uz UV-DAD detektor. Definisan je efikasan postupak za<br />pripremu uzoraka zemlji&scaron;ta u cilju hromatografskog određivanja SU.<br />Najefikasnija ekstrakcija ostvarena je primenom sme&scaron;e dihlormetanacetonitril<br />(2:1, v/v), zaki&scaron;eljene sirćetnom kiselinom (0,8%, v/v), uz dodatak<br />uree (0,3 g/ 10g zemlji&scaron;ta). Postupak mikrotalasne estrakcije u zatvorenom<br />sistemu omogućio je najbolje uslove za ekstrakciju SU. U cilju izdvajanja SU,<br />iz matriksa ekstrakata zemlji&scaron;ta, primenjena je ekstrakcija na čvrstoj fazi (SPE) sa silika gelom kao adsorbensom. Definisana metoda za određivanje<br />ispitivanih SU, kao i razvijeni postupak pripreme uzoraka, uspe&scaron;no je<br />primenjen u analizi realnih uzoraka zemlji&scaron;ta. Veoma dobre vrednosti testa<br />povrata ostvarene pri analizi primenom HPLC-UV-DAD metode, potvrdile su<br />pre svega ispravnost postupka pripreme uzoraka, a delom i kompletne<br />metode. Tačnost razvijene metode za određivanje SU u zemlji&scaron;tu potvrđena je<br />paralelnim analizama uzoraka zemlji&scaron;ta kori&scaron;ćenjem HPLC-MS-MS.<br />Primenom Studentovog t-testa (upareni), utvrđeno je da se rezultati paralelnih<br />analiza statistički značajno ne razlikuju (P=95%). Istraživanja u okviru<br />disertacije obuhvatila su i praćenje disipacije nikosulfurona, rimsulfurona,<br />oksasulfurona i prosufurona u različitim komercijalnim dozama primene<br />tokom 50 dana u polju na tri različite dubine (0-15 cm, 15-30 cm i 30-45 cm),<br />kao i laboratorijskim uslovima na dve temperature (250C i 300C). Vreme<br />polurazgradnje (DT50) ispitivanih SU (nikosulfuron, oksasulfuron i<br />prosulfuron) definisano Mitttag-Lefler-ovom funkcijom u ogledima u<br />laboratorijskim uslovima na 250C iznosilo je 0,65 dana (50 g ha-1 a.k.), 0,64<br />dana (160 g ha-1 a.k.) i 0,66 dana (30 g ha-1 a.k.), redom, a na 300C za<br />nikosulfuron 0,20 dana (50 g ha-1 a.k.) i prosulfuron 0,49 dana (50 g ha-1 a.k.).<br />DT50 za ispitivane SU u polju, takođe definisano Mitttag-Lefler-ovom<br />funkcijom, iznosilo je 72 minuta (0,05 dana), 0,23 dana, 0,12 dana i 0,15<br />dana, za nikosulfuron, rimsulfuron, oksasulfuron i prosulfuron, redom.<br />Značajno veća disipacija koja je utvrđena istraživanjima u okviru ove<br />disertacije najverovatnije je uzrokovana uticajem abiotičkih i biotičkih<br />procesa, kao i faktora spolja&scaron;nje sredine.</p> / <p>In this thesis a fast and selective method for determination and monitoring<br />of residues sulfonylurea herbicides (SU) (nicosulfuron, oxasulfuron,<br />tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and prosulfuron)<br />in soil, by applying high-performance liquid chromatography with UV<br />detector with diode array diodes (HPLC-UV-DAD) was developed. The<br />separation of the sulfonylurea was performed by use of a Zorbax Eclipse<br />XDB-C18 column. In order to define appropriate conditions of analysis,<br />the influence of the most significant the experimental factors was<br />investigated and defined. The following optimal conditions for gradient<br />elution: mobile phase acetonitrile (A) and 0.1% acetic acid (B) t = 0 min,<br />52% A; t = 2-2.5 min, 47% A; t = 2.5-5 min, 52% A were adopted at a<br />constant flow rate of 1 mL min-1 and column temperature of 250C. On<br />basis of the response of the analytical signal, its reproducibility and<br />linearity, the wavelength of 240 nm was adopted as an appropriate. The<br />influence of the matrix was expressed and therefore for the quantitative<br />determination of investigated SU in soil samples application of HPLCUV-<br />DAD methods was used MMC calibration curve. In the analysis of<br />extracts of nocontaminated soil limits of quantitation for nicosulfuron,<br />oxasulfuron, tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and<br />prosulfuron was achieved 3.16 &mu;g kg-1, 3.40 &mu;g kg-1, 3.76 &mu;g kg-1, 4.13 &mu;g<br />kg-1, 3.60 &mu;g kg-1, 3.04 &mu;g kg-1 and 2.97 &mu;g kg-1, respectively. The method<br />by using liquid chromatography-tandem mass spectrometry (HPLC-MSMS)<br />was defined in order to find more sensitive, more selective and more<br />accurate way to determine concentration SU in soil. HPLC-MS-MS was<br />used as the reference technique for checking results that have been<br />obtained by HPLC with UV-DAD detector. An efficient procedure<br />preparation of soil samples for the purpose chromatographic determination<br />of SU was defined. Using a mixture of dichloromethane-acetonitrile (2: 1,<br />v / v), acidified with acetic acid (0.8%, v / v), with the addition of urea (0.3<br />g / 10 g soil) was applied as the most effective way for extraction SU.<br />Microwave extraction process in a closed system allowed the best<br />conditions for the extraction of SU. In order to extract SU from matrix<br />exctracts soil the solid phase the extraction (SPE) with silica gel as an<br />adsorbent was used. The defined method for determination of investigated SU, as well as the developed procedure of sample preparation, was<br />successfully applied in the analysis of real samples of soil. The correctness<br />of procedure of sample preparation was confirmed with very good values<br />of recovery test which was applied in the analysis by using HPLC-UVDAD.<br />The accuracy of the developed method for determination of SU was<br />confirmed by coupled analysis soil samples using HPLC-MS-MS. The<br />results of parallel analysis does not differ significantly at 95% confidence<br />level. It was obtained using Student t-test (paired). The method developed<br />in this thesis was used for monitoring the dissipation of nicosulfuron,<br />rimsulfuron, oxasulfuron prosufuron, in different commercial doses of<br />application during 50 days in field at three different depths (0-15 cm, 15-<br />30 cm and 30-45 cm) and for laboratory conditions at two temperatures<br />(25&ordm;C and 30&ordm;C). The half-life time (DT50) of investigated SU were<br />calculated by use of Mitttag-Lefler function in experiments under<br />laboratory conditions at 25&ordm;C. The values of DT50 for nicosulfuron,<br />prosufuron and oxasulfuron read: 0.65 days (50 g ha-1 a.k.), 0.64 days (160<br />g ha-1 a.k.) and 0.66 days (30 g ha-1 a.k.), respectively. In the same type of<br />experiments at 30&ordm;C we get DT50 for nicosulfuron equals 0.20 days (50 g<br />ha-1 a.k.) and for prosulfuron equals 0.49 days (50 g ha-1 a.k.). The values<br />of DT50 on experiments in field were obtain also by use of Mitttag-Lefler&#39;s<br />function, and half-life times for nicosulfuron, rimsulfuron, oxasulfuron and<br />prosufuron from the commercially recommended doses, equal 72 minutes<br />(0.05 days), 0.23 days, 0.12 days and 0.15 days, respectively. Significantly<br />greater dissipation which was determined in this thesis was probably<br />caused by the influence of abiotic and biotic processes as well as<br />environmental factors.</p>

The main objective of this study was to extract phenolic compounds from caper and oleaster by using microwave. The effects of microwave power (400 and 700 W), extraction time (5-20 min), solid to solvent ratio (1:10, 1:20 and 1:30) and solvent type (water, ethanol and different ratios of ethanol-water mixture) on total phenolic content, antioxidant activity and concentration of the phenolic compounds in the extracts were investigated. In conventional extraction, extraction time and solvent type were used as independent variables. Microwave extraction was compared with conventional extraction. In caper and oleaster extracts that were obtained by using microwave, total phenolic compounds ranged between 5.0-52.4 and 2.6-43.0 mg GAE/g dry material while the antioxidant activity were between 0.5-2.0 and 0.2-3.7 mg DPPH/g dry material, respectively. Higher total phenolic content was observed with increasing solvent amount. The highest total phenolic content was obtained when 50% ethanol-water mixture was used as solvent. Microwave power did not affect total phenolic content significantly. The highest total phenolic contents were obtained when 400 W microwave power, 50% ethanol-water mixture and solid to solvent ratio of 1:30 were used in the extraction from both caper and oleaster. The best extraction time for caper was 5 min while it was 15 min for oleaster. The main constituents were rutin and kaempferol for both caper and oleaster extracts. For caper and oleaster there was no difference between extraction methods in terms of concentration of phenolic compounds. However, extraction time decreased significantly by using microwave, as compared to conventional extraction.

Les avancées scientifiques dans les plantes, les technologies de transformation, les biotechnologies permettent d’envisager à terme que des produits de la chimie verte du carbone renouvelable, substituables et compétitifs, remplaceront ceux issus des matières fossiles. En effet, l’un des grands thèmes de recherche actuelle en chimie est la chimie dite "propre". Dans ce cadre, le projet proposé vise une double valorisation de déchets issus de la filière "bois". La première valorisation concerne l’isolation de molécules extractibles, qui sont présentes en très faible quantité dans les matériaux lignocellulosiques, donc des produits à forte valeur ajoutée. La seconde valorisation concerne la transformation du résidu, après isolation des extractibles, en charbon actif, autre matériau à forte valeur ajoutée. Le procédé proposé concerne donc le secteur de la « chimie verte » avec une approche intégrée de « valorisation des déchets ». Nous avons utilisé comme matière première des déchets de pin maritime des Landes sous forme de sciure, à partir desquels nous avons extrait les composés volatils à partir de différents procédés intensifiés tels que les microondes et les ultrasons. L’huile obtenue a été caractérisée en déterminant sa quantité (rendement), sa composition, sa capacité antioxydante, la quantité en polyphénols qu’elle renferme, sa microstructure, etc. Afin que la valorisation de ces déchets soit totale, les résidus solides ont subi une pyro-activation physique avec du CO2 et de la vapeur d’eau comme agents activants pour produire du charbon actif. Une optimisation a été effectuée à partir des réponses suivantes : la surface BET, la taille des pores par adsorption d’azote à 77 K et les propriétés d’adsorption du charbon actif en phase aqueuse (paramètres de Langmuir et Freundlich). / The scientific advances in plants, processing technologies, biotechnology allow considering that the products of renewable carbon green chemistry, substitutable and competitive will replace the products issued from fossil material. In this framework, this project concerned a double valorization of waste from wood sector. The first valorization concerned the isolation of extractable compounds which are present in low quantities and could be considered as a high added value product. The second valorization deals with the transformation of the residue in another high added value product : the activated carbons. Thus, the proposed process concerns the sector of "green chemistry" with an integrated approach of "waste valorization". In the framework of this study, we used as raw material sawdust of maritime pine (pinus pinaster) from Landes area from an isolation of volatiles extracted by some intensified processes such as microwave and ultrasounds. The obtained oil was characterized by determining the quantity (yield), the composition, the antioxidant capacity, the polyphenols content and by studying the microstructure. To achieve a total valorization the residues were submitted to a pyro-activation with CO2 and water vapor as activating agents to produce an activated carbon. An optimization was carried out according to different responses as the BET surface, the pores size by nitrogen adsorption at 77 K and the adsorption properties of activated carbon in aqueous phase (Langmuir et Freundlich parameters).

<p>U okviru doktorske disertacije optimizovani su uslovi određivanja<br />metilestara masnih kiselina, uključujući i trans izomere, primenom<br />kapilarne gasne hromatografije&ndash;masene spektrometrije, na<br />kapilarnoj koloni SP-2560 (dužina x unutra&scaron;nji prečnik: 100 m x<br />0,25 mm, debljina sloja stacionarne likvidne faze 0,20 &mu;m,<br />biscijanopropil polisiloksan). Kori&scaron;ćenjem standarnih rastvora<br />metilestara masnih kiselina optimizovani su temperaturni program,<br />odnos razdeljivanja i uslovi akvizicije podataka SCAN tehnikom.<br />Razvijena je metoda za pripremu uzoraka u cilju određivanja sastava<br />masnih kiselina u prehrambenim proizvodima gasnom<br />hromatografijom&ndash;masenom spektrometrijom zasnovana na<br />istovremenoj mikrotalasnoj ekstrakciji i esterifikaciji (SMEE).<br />Validacija metode je izvedena poređenjem sa rezultatima dobijenim<br />gasnom hromatografijom&ndash;masenom spektrometrijom nakon<br />ekstracije po Soxhlet-u i derivatizacije masnih kiselina u metilestre<br />masnih kiselina. Rezultati dobijeni primenom razvijene i referentne<br />metode bili su statistički isti, kako u pogledu sastava masnih<br />kiselina, tako i efikasnosti ekstrakcije. Rezultati su pokazali da su<br />prednosti SMEE u odnosu na konvencionalnu metodu: kratko vreme<br />pripreme uzoraka i samim tim manja potro&scaron;nja energije, kao i<br />upotreba malih količina skupih organskih rastvarača. Dobro slaganje<br />rezultata dobijenih primenom referentne i metode zasnovane na<br />istovremenoj mikrotalasnoj ekstrakciji i esterifikaciji pokazuje da bi<br />se SMEE mogla primeniti kao rutinska metoda za pripremu uzoraka<br />prehrambenih proizvoda u cilju određivanja trans masnih kiselina<br />(TFA). Određen je sastav masnih kiselina, sa posebnim akcentom na<br />trans masne kiseline, u 273 uzoraka prikupljenih sa na&scaron;eg trži&scaron;ta u<br />periodu od juna 2006. do juna 2009. godine. Sadržaj trans masnih<br />kiselina u analiziranim uzorcima prehrambenih proizvoda, sirovina i<br />međuproizvoda koji se koriste u pekarskoj i konditorskoj industriji,<br />kretao se u veoma &scaron;irokom intervalu, od 0,0% do čak 48,7%.<br />Prosečan sadržaj trans masnih kiselina iznosio je 0,2% u uljima,<br />6,5% u jestivim margarinima, 19,9% u margarinima za domaćinstvo,<br />9,8% u industrijskim margarinima, 24,3% u namenskim mastima,<br />10,8% u masnim punjenjima, 1,6% u mlečnim proizvodima, 10,9%<br />u slanom trajnom pecivu, 10,2% u čajnom pecivu, 6,3% u tvrdom<br />keksu, 11,0% u vafel proizvodima, 10,6% u čokoladnim<br />proizvodima i 9,2% u karamelama. Od ukupno 124 analizirana<br />uzorka, koja se ne koriste za direktnu upotrebu u ishrani (namenske<br />masti, masna punjenja, industrijski i margarini za domaćinstvo) 86<br />uzoraka (69,3%) sadrži vi&scaron;e od 5% trans masnih kiselina, 25<br />(20,2%) sadrži manje od 5% TFA, dok u 13 uzoraka (10,5%) nije<br />detektovano prisustvo trans izomera. Od ukupno 140 analiziranih<br />uzoraka, koji se koriste za direktnu upotrebu u ishrani 74 uzoraka<br />(52,8%) sadrži vi&scaron;e od 2% trans masnih kiselina, 20 (14,3%) sadrži<br />manje od 2% TFA, dok u 46 uzoraka (32,9%) nije detektovano<br />prisustvo trans izomera.</p> / <p>In this thesis, operating conditions for fatty acids determination,<br />including trans isomers, by capillary gas chromatography&ndash;mass<br />spectrometry, on capillary column SP-2560 (100 m x 0.25 mm, with<br />a 0.20 &mu;m film thickness of biscyanopropyl polysiloxane liquid<br />phase) were optimized. Temperature program, split ratio and<br />condition of data acquisition by SCAN technique were optimized<br />using standard solutions of fatty acid methyl esters. A sample<br />preparation method based on simultaneous microwave assisted<br />extraction&ndash;esterification (SMEE) was developed for the<br />determination of the fatty acid composition of foodstuffs by gas<br />chromatography&ndash;mass spectrometry. The proposed sample<br />preparation method was validated by comparison with the reference<br />Soxhlet extraction method followed by derivatisation by methyl<br />ester formation and the same determination step. The fatty acid<br />compositions, as well as extraction efficiencies obtained by the use<br />of the proposed SMEE method and reference method were<br />statistically similar. The results showed that compared to the<br />conventional method, SMEE method offer the advantages of short<br />sample preparation time, low consumption of expensive organic<br />solvents and less energy consumption. This good agreement between<br />results provided, both by the SMEE and reference method,<br />demonstrates the usefulness of the former as the routine method for<br />the treatment of food samples prior to trans fatty acid analysis. The<br />fatty acid composition, and trans fatty acid content of 273 samples<br />collected from June 2006 to June 2009 year were determined. Trans<br />fatty acid content in the analysed samples of food products, raw<br />materials and intermediate products used in bakery and<br />confectionery industry was ranged in a very wide interval, from<br />0.0% to 48.7%. The average contents of trans fatty acids were 0.2%<br />in oils, 6.5% in the edible margarines, 19.9% in cooking margarines,<br />9.8% in industrial margarines, 24.3% in shortenings, 10.8 % in fat<br />fillings, 1.6% in dairy products, 10.9% in crackers, 10.2% in tea<br />cookies, 6.3% in biscuits, 11.0% in wafer products, 10.6% in<br />chocolate products and 9.2% in the caramels. From the total of 124<br />analysed samples, which are not used for direct human consumption<br />(shortenings, fat fillings, industrial and cooking margarines) 86<br />samples (69.3%) contained more than 5% trans fatty acids, 25 (20.2<br />%) contained less than 5% TFA, while 13 samples (10.5%) had an<br />undetectable levels of trans isomers. From a total of 140 analysed<br />samples, which are used for direct human consumption 74 food<br />samples (52.8%) contained more than 2% trans fatty acids, 20<br />(14.3%) contained less than 2% TFA, while 46 samples (32.9%) had<br />an undetectable levels of trans isomers.</p>

This thesis deals with optimization of conditions for the determination of platinum by electrothermal atomic absorption spectrometry. The theoretical part describes the occurrence of platinum in different part of the environment, its physical and chemical properties, transport and bioavailability. There is also evaluated appropriate method for determination and preconcentration of platinum. The experimental part describes advance of optimize the measurement conditions for ETA-AAS, further is describes optimization of condition for SPE and work with real samples on which are applied this conditions.

ABSTRACT SOLVENT-FREE MICROWAVE EXTRACTION AND MICROWAVEASSISTED HYDRODISTILLATION OF ESSENTIAL OILS FROM SPICES Bayramoglu, Beste M.S., Department of Food Engineering Supervisor: Assoc. Prof. Dr. Serpil Sahin Co-Supervisor: Assoc. Prof. Dr. S. G&uuml / l&uuml / m S&uuml / mn&uuml / September 2007, 130 pages The undesirable effects of conventional methods generated the need for economical and safe techniques in the extraction of essential oils. Microwave-assisted hydrodistillation (MAHD) and solvent-free microwave extraction (SFME) are recently developed techniques, which are thought to overcome this problem. Oregano (Origanum vulgare L.), laurel (Laurus nobilis L.) and rosemary (Rosmarinus officinalis L.) were chosen in this study since they have high antimicrobial and antioxidant effects and are widely grown and consumed in Turkey. The objectives of this study were to examine the applicability of SFME in the extraction of essential oils from oregano and laurel, and MAHD in the extraction of rosemary essential oil. The effects of microwave power and extraction time on the yield, composition, and other quality parameters of the extracts were also investigated. Hydrodistillation was performed as control. SFME offered significantly higher essential oil yields (0.054 mL oil/g oregano) from oregano as compared to hydrodistillation (0.048 mL oil/g oregano). Conventional process time was reduced by 80%. Main aroma compound was thymol (650-750 mg thymol/mL oil). For laurel, no significant differences were obtained in yields (about 0.022 mL oil/g laurel) obtained by SFME and hydrodistillation. Process time was reduced by 55-60%. Main aroma compound was 1,8-cineole (630-730 mg 1,8-cineole/mL oil). In the case of rosemary, no significant differences were obtained in yields (about 0.026 mL oil/g rosemary) obtained by MAHD at 622 W and hydrodistillation. The process time was reduced by about 65%. Main aroma compounds were 1,8-cineole (430-500 mg 1,8-cineole/mL oil) and camphor (150-210 mg camphor/mL oil). Keywords: Solvent-free microwave extraction (SFME), Microwave-assisted hydrodistillation (MAHD), Origanum vulgare L., Laurus nobilis L., Rosmarinus officinalis L.

Cette étude présente une dimension économique, sociale et environnementale très importante. Elle rentre dans le cadre du projet Franco-Marocain PHC Toubkal (Ecopama, Volubilis 2012). Son objectif majeur est de valoriser les écorces Marocaine d’Acacia mollissima par une extraction verte permettant l’obtention des produits réactifs, des tanins condensés, qui seront utilisés dans le collage des panneaux de contreplaqués. Trois méthodes d’extraction ont été étudiées. Deux sont conventionnelles, une macération et une infusion ; ces deux techniques d’extraction sont simples, peu coûteuses. La troisième est une extraction assistée par micro-ondes ; c’est une technique innovante, rapide et peu consommatrice en solvant. La méthodologie des plans d’expériences est utilisée dans cette étude pour déterminer les facteurs les plus significatifs pour l’amélioration du rendement d’extraction des tanins condensés, optimiser les conditions d’extractions, réduire la proportion de solvant utilisé ainsi que le temps d’extraction. L’impact des conditions d’extraction et des méthodes d’extraction sur la teneur des tanins condensés sont étudiés pour la première fois pour les écorces d’Acacia mollissima du Maroc. Les extraits ont été caractérisés par des dosages colorimétriques, par des analyses structurales et thermiques. Les trois méthodes d’extraction ont été comparées. La teneur des extractibles est affectée par la proportion de solvant utilisé et le temps d’extraction. L’extraction assistée par micro-onde présente des teneurs en tanins condensés supérieure à l’extraction par des méthodes conventionnelles mais la teneur en sucre extraits est aussi élevée. Des formulations de colles à base de tanin et de lignosulfonate ont été élaborées en utilisant l’hexamine comme durcisseur. La colle biosourcée et ses constituants ont été caractérisés par analyse thermogravimétrique (ATG), et par calorimétrie différentielle à balayage (DSC). Les propriétés thermomécaniques et mécaniques des colles élaborées sont évaluées. L’optimisation des conditions de pressage des panneaux de contreplaqués, ainsi que le ratio tanin-lignosulfonate glyoxalé, ont été réalisées. La résistance des panneaux à l’eau froide et chaude est améliorée par l’addition de la résine époxy aux formulations de colle. Les propriétés mécaniques des panneaux de contreplaqués encollés ont été évalués par des tests normatifs et ont été comparés à celle des résines synthétiques commerciales (urée formaldéhyde et phénol formaldéhyde). La qualité de collage des panneaux élaborés a été évaluée. Les différentes colles présentent des caractéristiques physiques et thermiques satisfaisantes et acceptables pour les industries de collage des panneaux de bois. Des panneaux de contreplaqués avec de bonnes performances mécaniques et une excellente résistance à l’eau froide et bouillante ont été fabriqués. Ces colles présentent une qualité de collage qui se rapproche de celle des résines phénol-formaldéhyde, et peuvent être utilisées avec succès, pour une application industrielle des panneaux de contreplaqués, en milieu sec, humide et extérieur. / This study has an important economical, social and environmental dimension. It was conducted within the framework Franco-Moroccan PHC Toubkal "Ecopama, Volubilis 2012". The desire to enhance Moroccan bark of Acacia mollissima by the use of green extraction and also to obtain reagent products, condensed tannins, was the main objective of this study. These tannins will be used in the bonding of plywood panels. Three extraction methods were studied. Two are conventional, maceration and infusion; witch is simple and cheap extraction method. The third is microwave assisted extraction which is a fast, innovative method using a small amount of solvent. The experimental design methodology was used to identify the significant factors to improve yield extraction of condensed tannins, to optimize extraction process, to reduce solvent proportion and time extraction. The impact of extraction conditions and extraction process were studied for the first time on condensed tannins contents extracted from Moroccan bark of Acacia mollissima. The extracts were characterized using colorimetric assays, structural and thermal analysis.The three types of extraction were compared. The extractibles contents were affected by solvent proportion and also time extraction. Microwave assisted extraction produced a higher condensed tannins than the conventional method but in the other hand the sugars extracted is more important. Tannin-lignosulfonate adhesives were produced using hexamine as a hardener. The biobased adhesive formulations and their compounds were compared using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and by determining the thermal and mechanical proprieties of the adhesives. Optimal tannin-glyoxalated lignosulfonates ratio and pressing conditions of plywood panels were measured. The resistance of plywood panels to the cold and hot water was improved by the addition of epoxy resin in adhesive formulations. Mechanical properties of plywood panels made with tannin-lignosulfonates-epoxy adhesives were evaluated using normative standard and compared to those of panels made with a commercial resins (urea formaldehyde and phenol formaldehyde). The bonding quality of plywood panels elaborated was evaluated. The various adhesives elaborated have satisfactory and acceptable physical and thermal characteristics for bonding panels used in wood industries. Plywood panels with good mechanical performance, good resistance to cold water and to boiling water, were produced. The bonding quality of the adhesives elaborated in laboratory scale presented approximate proprieties than the phenol-formaldehyde resins which can use with successfully in dry, wet and exterior industrial application of plywood panels.

This work is based on the occurrence of drug residues in the environment. This study is focused on the development and optimization methods for determination of selected drugs in the surface water, aquatic sediment and sewage sludge from waste water treatment plant. From the group of drugs were chosen antibiotics. Antibiotics presented in the environment can cause adverse effects including toxic effects, immunity disorders and indirect bioalteration effects. Sulfonamide antibiotics, which are used in the treatment of urinary and respiratory tract infections as well as in the treatment of other infectious diseases, were chosen as a target compounds. Three optimized analytical methods for determination of sulfonamide antibiotics were developed. For the optimization of extraction were tested: solid phase extraction, pressurized solvent extraction, microwave extraction and ultrasonic extraction. For the final analysis was used liquid chromatography with two detectors - diode array detector and mass spectrometer. These optimized methods were applied for the analysis of real samples. The surface water and sediment samples were collected from two Moravian rivers (the Svratka river and the Svitava river). Samples of sewage sludge were collected from waste water treatment plant Brno-Modřice. Fish samples from the Svratka river were also collected. It was observed that all the selected sulfonamide antibiotics are present in real sediment samples (ug.kg-1). Simultaneously presence of some target analytes in real surface water (ug.l-1) and in sewage sludge (ug.kg-1) samples has been confirmed. In samples of surface water from the Svitava river and in fish samples sulfonamide antibiotics were not detected or their concentrations were below the limit of detection.