Este trabalho descreve a otimização e validação de um método analítico para a análise de hidrocarbonetos policíclicos aromáticos (PAHs) em água usando uma interface SPME/LC/DAD. Parâmetros como tipos de fibra, tempo de extração, temperatura e força iônica foram estudados no modo \"off line\" e a influência destes na eficiência de extração foi avaliada. Os melhores resultados foram obtidos com a fibra Carbowax/templeted resin. Uma interface \"lab made\" foi utilizada para a etapa de validação e as curvas de calibração mostraram boa linearidade (r>0,99) para a maioria dos compostos analisados, tanto na linearidade da amostra como na linearidade do padrão. Os dados de precisão obtidos na concentração de trabalho variaram de 1 a 3%, aproximadamente, e os valores de recuperação se mantiveram na faixa de 4 a 27%. Os PAHs foram determinados na faixa de 0,025 micro g até 0,5 micro g. Pode-se considerar os valores obtidos nos itens de precisão e linearidade satisfatórios para a análise dos PAHs, considerando-se os critérios internacionais estabelecidos para esta classe de compostos, mas o método não atende as especificações relacionadas a recuperação e faixa de concentração. / This work describes the optimization and validation of an analytical method to determine Polycyclic Aromatic Hydrocarbons (PAHs) in water using a SPME/LC/DAD interface. Parameters as fibers kind, sampling time, temperature and ionic strength were studied and their influence on the extraction efficiency were evaluated. The best results were obtained with the Carbowax/templeted resin fiber. A \"lab made\" interface was used to validate the method and the calibration curves showed good linearity (r > 0,99) to almost all the compounds analyzed, considering both the sample linearity and the standard linearity. The data obtained for precision showed a variation from 1 to 3 % and the recovery values were bellow 27%. The PAHs analysis was performed for concentrations from 0,025 micro g/fiber to 0,5 micro g/fiber. The method does not show good recoveries values but the data obtained for precision and linearity can be considered satisfactory according to international criteria established for theses compounds.

Este trabalho descreve a otimização e validação de um método analítico para a análise de hidrocarbonetos policíclicos aromáticos (PAHs) em água usando uma interface SPME/LC/DAD. Parâmetros como tipos de fibra, tempo de extração, temperatura e força iônica foram estudados no modo \"off line\" e a influência destes na eficiência de extração foi avaliada. Os melhores resultados foram obtidos com a fibra Carbowax/templeted resin. Uma interface \"lab made\" foi utilizada para a etapa de validação e as curvas de calibração mostraram boa linearidade (r>0,99) para a maioria dos compostos analisados, tanto na linearidade da amostra como na linearidade do padrão. Os dados de precisão obtidos na concentração de trabalho variaram de 1 a 3%, aproximadamente, e os valores de recuperação se mantiveram na faixa de 4 a 27%. Os PAHs foram determinados na faixa de 0,025 micro g até 0,5 micro g. Pode-se considerar os valores obtidos nos itens de precisão e linearidade satisfatórios para a análise dos PAHs, considerando-se os critérios internacionais estabelecidos para esta classe de compostos, mas o método não atende as especificações relacionadas a recuperação e faixa de concentração. / This work describes the optimization and validation of an analytical method to determine Polycyclic Aromatic Hydrocarbons (PAHs) in water using a SPME/LC/DAD interface. Parameters as fibers kind, sampling time, temperature and ionic strength were studied and their influence on the extraction efficiency were evaluated. The best results were obtained with the Carbowax/templeted resin fiber. A \"lab made\" interface was used to validate the method and the calibration curves showed good linearity (r > 0,99) to almost all the compounds analyzed, considering both the sample linearity and the standard linearity. The data obtained for precision showed a variation from 1 to 3 % and the recovery values were bellow 27%. The PAHs analysis was performed for concentrations from 0,025 micro g/fiber to 0,5 micro g/fiber. The method does not show good recoveries values but the data obtained for precision and linearity can be considered satisfactory according to international criteria established for theses compounds.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / To evaluate the effects of the environmental on the content of secondary metabolites in the genotypes of Lippia gracilis Schauer, a high-performance liquid chromatographic-photodiode array detection (HPLC-DAD) method was developed to obtain the chemical profiles (fingerprints) of infusions from leaves of seven genotypes of L. gracilis originated from two locations (Sergipe and Bahia state) and collected in different seasons: summer (with and without irrigation) and winter. In order to compare the fingerprints chromatograms, it was applied chemometric tools for exploratory analysis (PCA). The results of these analyses showed that 108 and 202 genotypes collected in summer and grown without irrigation are significantly different from other genotypes under the same conditions. Moreover, knowing that this species is drought-resistant and can withstand high temperatures, we can propose that the 107, 108 and 110 genotypes are more resistant to drought conditions because there were no differences between samples collected in summer and grown with or without irrigation. All samples was submitted to antioxidant activity by DPPH method (2,2-diphenyl-1-picrylhydrazyl). The samples of 201 genotype collected in summer with and without irrigation, 201vc and 201vs (30 μg/mL; 60 min), respectively, exhibited more than 90% DPPH scavenging activities, displaying similar response to the positive control, gallic acid (92.06%, 30 mg/mL, 60 min). / Para avaliar os efeitos do meio ambiente no conteúdo de metabólitos secundários em genótipos de Lippia gracilis Schauer, um método por cromatografia líquida de alta eficiência com detector por arranjo de diodos (CLAE-DAD) foi desenvolvido para obter os perfis cromatográficos (fingerprint) de chás das folhas secas de sete genótipos desta espécie provenientes de duas localizações (Sergipe e Bahia) e coletadas em diferentes estações do ano: verão (com e sem irrigação) e inverno. Para comparar os cromatogramas fingerprints foi aplicado ferramentas quimiométricas de análise exploratória (ACP). Os resultados destas análises mostraram que os genótipos 108 e 202 coletados no verão e cultivados sem irrigação são significativamente diferentes dos demais genótipos da mesma coleta. Além disso, sabendo que esta espécie possui grande resistência à seca e a altas temperaturas, pode-se propor que os genótipos 107, 108 e 110 apresentaram maior resistência ao stress hídrico, pois não foi observada diferenciação entre as amostras coletadas no verão cultivadas com e sem irrigação. Os chás das amostras de L. gracilis foram também submetidos ao teste de atividade antioxidante pelo método DPPH (2,2 difenil-1-picril hidrazil). As amostras do genótipo 201, verão com irrigação e verão sem irrigação [(201 vc e 201 vs); 30 μg/mL; 60 min)] consumiram mais de 90% do radical DPPH, apresentando uma resposta similar ao controle positivo ácido gálico (92,06%, 30 μg/mL, 60 min).

<p>Kao &scaron;to je poznato, RS-2-(4-hlor-o-toliloksi)propionska kiselina (MCPP),&nbsp;(4-hlor-2-metilfenoksi)sirćetna kiselina (MCPA) i 3,6-dihlorpiridin-2-karboksilna kiselina &nbsp;(klopiralid) su herbicidi sa veoma &scaron;irokim spektrom dejstva, a pored toga su rastvorljivi u&nbsp;vodi, te&scaron;ko biorazgradljivi i prema literaturnim podacima su, nažalost, veoma često prisutni&nbsp;herbicidi u pijaćoj vodi. Proces heterogene fotokatalize uz primenu TiO₂i UV zračenja se&nbsp;pokazao kao veoma pogodan način za njihovo uklanjanje iz vode. Međutim, zbog velikog&nbsp;energetskog procepa od 3,2 eV (anataze-oblik), odnosno, 3,0 eV (rutil-oblik), veoma mali&nbsp;udeo bliskih UV zraka iz sunčeve svetlosti (oko 3&minus;4%) biva iskori&scaron;ćen u toku&nbsp;fotokatalitičkog procesa, &scaron;to ukazuje na to da je TiO_2&nbsp;praktično neaktivan u prisustvu&nbsp;sunčeve svetlosti. Na osnovu literaturnih podataka je zapaženo da postoji mogućnost&nbsp;fotorazgradnje pojedinih supstrata u prisustvu TiO_2&nbsp;primenom vidljive svetlosti. Na&nbsp;primeru MCPP je ispitana aktivnost TiO_2&nbsp;Degussa P25 kao fotokatalizatora u prisustvu&nbsp;vidljive svetlosti. Na osnovu refleksionih spektara je utvrđeno da MCPP adsorbovan na&nbsp;TiO_2&nbsp;Degussa P25 apsorbuje vidljivi deo spektra (&lambda; &ge;400 nm). Nastali prelazni kompleks&nbsp;je potvrđen FTIR merenjima. Efikasnost TiO2Degussa P25 primenom vidljive svetlosti je&nbsp;upoređena sa sunčevim i UV zračenjem, kao i direktnom fotolizom u prisustvu pomenutih&nbsp;izvora zračenja. Brzina fotokatalitičke razgradnje MCPP primenom vidljive svetlosti iznosi&nbsp;0,86 &mu;mol dm^&minus;3min^&minus;1, &scaron;to je oko 4 puta brže u poređenju sa direktnom fotolizom. Nadalje&nbsp;je ustanovljena optimalna masena koncentracija katalizatora od oko 8 mg cm^&minus;3, koja je&nbsp;znatno vi&scaron;a u poređenju sa primenom UV zračenja. Razlog je najverovatnije različit&nbsp;mehanizam fotorazgradnje koji se odvija primenom vidljivog i UV zračenja. Naime,&nbsp;prisustvo 2-metil-2-propanola (poznatog hvatača&nbsp;^&bull;OH-radikala) praktično ne utiče na&nbsp;brzinu fotokatalitičke razgradnje MCPP p rimenom vidljive svetlosti, &scaron;to ukazuje da se&nbsp;mehanizam razgradnje MCPP primenom &nbsp;vidljive svetlosti ne odvija posredstvom&nbsp;^&bull;OH-radikala, za razliku od onog uz primenu UV zračenja.</p><p>S obzirom da se katalizator TiO_2&nbsp;Degussa P25 uz primenu vidljive svetlosti nije&nbsp;<br />pokazao kao naročito efikasan kada je u pitanju razgradnja sva tri herbicida i imajući u&nbsp;vidu da se u poslednje vreme iz razloga praktične primene sve vi&scaron;e pribegava procesu dopovanja TiO_2&nbsp;različitim tipovima metala (alkalnih, zemnoalkalnih, prelaznih i dr.) i nemetala (halogenida, halkogenida i dr.), u okviru ove doktorske disertacije je ispitana aktivnost N-TiO₂(sintetisanih mokrim i suvim putem) i TiO_2&nbsp;(rutil) dopovanog sa različitim količinama Fe³⁺-jona (0,13&minus;1,48 at.%) pri razgradnji herbicida MCPP i MCPA primenom vidljive svetlosti. Pored toga je ispitana efikasnost TiO_2&nbsp;(anataze) takođe dopovanog sa različitim količinama Fe³⁺-jona (0,71&minus;1,80 at.%) na primeru MCPP.&nbsp;</p><p>Poredeći N-TiO_2&nbsp;(sintetisan mokrim putem) i N-TiO_2&nbsp;(sintetisani suvim putem), primećeno&nbsp;je da je u drugom slučaju efikasnost katalizatora veća oko 2 puta. Isto tako je zapažena u&nbsp;slučaju MCPP ne&scaron;to veća fotokatalitička aktivnost N-TiO_2&nbsp;(sintetisani suvim putem) u&nbsp;poređenju sa TiO_2&nbsp;(anataze). Kada je u pitanju MCPA aktivnost sva tri katalizatora je&nbsp;veoma slična. Pored toga je zapažena veća efikasnost N-TiO_2&nbsp;(sintetisan mokrim putem) u&nbsp;poređenju sa TiO_2&nbsp;Degussa P25 (oko 1,5 puta) i oko 5 puta u odnosu na direktnu fotolizu,&nbsp;dok su N-TiO_2&nbsp;(sintetisani suvim putem) oko 3 puta efikasniji u poređenju sa TiO_2&nbsp;Degussa P25 i oko 10 puta u &nbsp;poređenju sa direktnom fotolizom. Brzina solarne razgradnje&nbsp;je preko 100 puta manja nego primenom vidljivog i UV zračenja, &scaron;to je posledica različitih&nbsp;intenziteta pomenutih izvora ozračivanja i različitih uslova pri kojima je vr&scaron;ena razgradnja. &nbsp;Ustanovljena je optimalna masena koncentracija N-TiO_2&nbsp;(sintetisan mokrim putem) od&nbsp;4 mg cm^&minus;3.</p><p>Prilikom razgradnje MCPP i MCPA je nađeno da je brzina veća kada se kao&nbsp;katalizator &nbsp;koristi TiO_2&nbsp;(rutil) u poređenju sa Fe-TiO_2&nbsp;i da sa povećanjem količine Fe³⁺-jona fotokatalitička aktivnost uglavnom opada. Kada je kao fotokatalizator kori&scaron;ćen TiO_{2 &nbsp;}<br />(anataze) dopovan različitim količinama Fe³⁺-jona (od 0,71 do 1,80 at.%), razgradnja&nbsp;<br />MCPP je u svim slučajevima znatno sporija u odnosu na TiO_2&nbsp;(anataze).</p><p>S obzirom da su prema literaturnim podacima kinetika i mehanizam fotokatalitičke&nbsp;<br />razgradnje klopiralida nepoznati, ispitana je njegova stabilnost pri različitim&nbsp;eksperimentalnim uslovima. Tokom ispitivanja uticaja pH kako u prisustvu, tako i u&nbsp;odsustvu dnevne svetlosti u intervalu pH od 1,0&minus;9,0, nađeno je da ni u jednom slučaju ne&nbsp;dolazi do razgradnje supstrata u periodu od sedam meseci koliko je proces praćen. Takođe&nbsp;je ispitana kinetika fotokatalitičke razgradnje klopiralida primenom UV i vidljivog&nbsp;zračenja u prisustvu TiO_2&nbsp;Degussa P25, kao i direktna fotoliza primenom oba izvora&nbsp;zračenja. Nađeno je da je brzina fotokatalitičke razgradnje primenom UV zračenja veća&nbsp;oko 5 puta u odnosu na direktnu fotolizu. Za praćenje toka fotokatalitičke razgradnje&nbsp;klopiralida je izabrana pH-vrednost od 3,2. Nadalje je zapaženo da se u ispitivanom opsegu početnih koncentracija supstrata (0,5&ndash;3,0 mmol dm^&minus;3) kinetika fotokatalitičke razgradnje klopiralida može opisati pseudo-prvim redom. Pri ispitivanju uticaja masene koncentracije katalizatora (0,5&ndash;8 mg cm^&minus;3) na brzinu razgradnje klopiralida, ustanovljena je optimalna masena koncentracija primenjenog fotokatalizatora od oko 4 mg cm^&minus;3. Izračunata ukupna &nbsp;prividna energija aktivacije iznosi 7,74 kJ mol^&minus;1. Pored toga, prisustvo kiseonika ubrzava reakciju 2 puta, dok dodatak elektron-akceptora kao &scaron;to su (NH₄)₂S₂O₈, H₂O_2&nbsp;i KBrO_3&nbsp;pokazuje značajan i različit efekat na kinetiku fotokatalitičke razgradnje klopiralida. Pri ispitivanju uticaja etanola, kao hvatača slobodnih radikala, nađeno je da se heterogena fotokataliza odvija uglavnom preko ^&bull;OH-radikala.</p><p>Na osnovu LC&ndash;MS/MS (ESI+) merenja ustanovljeno je prisustvo nekoliko&nbsp;intermedijera: 3,6-dihlor-piridin-2-ol, 3,6-dihlor hidroksipiridin-2-karboksilna kiselina i&nbsp;3,3&#39;,6,6&#39;-tetrahlor-2,4&#39;-bipiridin-2&#39;-karboksilna kiselina. Na osnovu identifikovanih&nbsp;intermedijera, kao i kinetičkih rezultata, predložen je mogućput mehanizma fotokatalitičke&nbsp;razgradnje klopiralida.</p><p>Prilikom ispitivanja uticaja strukture molekula na brzinu razgradnje, konstatovano&nbsp;<br />je da u slučaju klopiralida praktično ne dolazi do fotokatalitičke razgradnje u prisustvu&nbsp;TiO_2&nbsp;(anataze) i N-TiO_2&nbsp;(sintetisani suvim putem) uz primenu vidljive svetlosti, kao i u&nbsp;slučaju TiO_2&nbsp;Degussa P25. Pored toga, primenom TiO_2&nbsp;(rutil) i Fe-TiO_2&nbsp;kao&nbsp;fotokatalizatora, sa povećanjem količine Fe³⁺-jona od 0,13 do 1,27 at.% raste brzina&nbsp;razgradnje klopiralida, ukazujući da strukturne osobine supstrata utiču na brzinu njihove&nbsp;razgradnje.</p> / <p>It is well known that RS-2-(4-chloro-o-tolyloxy)propionic acid (MCPP), (4-chloro-2- methyl-phenoxy)acetic acid (MCPA) and 3,6-dichloropyridine-2-carboxylic &nbsp;acid&nbsp;(clopyralid) are herbicides of wide activity spectrum. They are soluble in water, hardly&nbsp;biodegradable and, unfortunately, often present in drinking water.</p><p>Heterogeneous photocatalysis by application of TiO_2&nbsp;and UV radiation proved to&nbsp;be very suitable for their removal from water. However, due toits large energy gap, i.e.&nbsp;3.2 &nbsp;eV (anatase-form) and 3.0 eV (rutile-form), a very small fraction of sunlight in the near&nbsp;UV range (about 3&ndash;4%) is used during photocatalytic process, which is an indication of&nbsp;TiO_2&nbsp;inactivity in the presence of this light source. Some literature data report on the&nbsp;possibility of photodegradation of certain substrates by visible light in the presence of&nbsp;TiO₂. MCPP served as substrate for testing TiO_2&nbsp;Degussa P25 &nbsp;photocatalytic activity in the&nbsp;presence of visible light. On the basis of reflection spectra it was established that MCPP&nbsp;adsorbed on TiO_2&nbsp;Degussa P25 was absorbing visible spectrum radiation (&lambda; &ge;400 nm).&nbsp;The existence of thus formed &nbsp;charge-transfer complex was confirmed with FTIR analysis.&nbsp;The efficiency of &nbsp;TiO_2&nbsp;Degussa P25 with application of visible light was compared to&nbsp;sunlight and UV radiation, as well to directphotolysis in the presence of these light&nbsp;sources. The rate of MCPP photocatalytic degradation by means of visible light is&nbsp;0.86 &mu;mol dm^{&minus;3&nbsp;}min^&minus;1, which is about 4 times faster than direct photolysis. In addition, the&nbsp;optimal &nbsp;catalyst concentration of about 8 mg cm^&minus;3, much higher than using UV radiation,&nbsp;<br />was established. The reason is, probably, a different mechanism of &nbsp;hotodegradation &nbsp;in the&nbsp;presence of visible and UV irradiation. Namely, the presence of 2-methyl-2-propanol&nbsp;(well-known&nbsp;^&bull;OH radical scavenger) has practicallyno effect on the rate of &nbsp;MCPP&nbsp;photocatalytic degradation using visible light, which points that this degradation&nbsp;mechanism does not involve&nbsp;^&bull;OH radicals, in contrast to that established &nbsp;for UV radiation.</p><p>Since the catalyst TiO_2&nbsp;Degussa P25 with application of visible light was not very&nbsp;<br />efficient in degradation of all three herbicidesand in view that nowadays is very &nbsp;popular&nbsp;doping process of TiO₂ with different types of metals (alkali, alkaline-earth, transition, etc.)&nbsp;and non-metals (halogen, chalcogen, etc.), in the scope of this Ph.D. &nbsp;thesis activities of N-TiO_2&nbsp;(synthesized by wet and dry procedure) and TiO_2&nbsp;(rutile) doped with various amounts&nbsp;of Fe^3+&nbsp;(0.13&ndash;1.48 at.%) in degradation processes of &nbsp;herbicides MCPP and MCPA using&nbsp;visible light were studied. In addition, the efficiency of TiO_2&nbsp;(anatase) doped with various&nbsp;amounts of Fe^3+&nbsp;(0.71&ndash;1.80 at.%) was also tested for MCPP degradation. When comparing&nbsp;N-TiO_2&nbsp;(synthesized by wet procedure) and N-TiO₂ (dry procedure), it was observed that&nbsp;in the latter case the catalyst efficiency was about two times higher. In this case for MCPP&nbsp;was also observed somewhat higher photocatalytic activity of N-TiO₂ (synthesized by dry&nbsp;procedure) in comparison with TiO₂. When activities of all three catalysts towards MCPA&nbsp;are compared, the results are very alike. In addition, higher efficiency of N-TiO_{2 &nbsp;}(wet&nbsp;procedure) comparing to TiO_2&nbsp;Degussa P25 (about 1.5 times) and about 5 times in&nbsp;comparison to direct photolysis were recorded, while N-TiO₂ (dry procedure) was about 3&nbsp;times more efficient than TiO_2&nbsp;Degussa P25 and about 10 times in comparison with direct&nbsp;photolysis. The rate of solar degradation is about 100 times lower than by application of&nbsp;UV and visible radiation, as a consequence of various intensities of the mentioned light&nbsp;sources and different conditions of photodegradation. An optimal concentration of N-TiO₂&nbsp;(wet procedure) of 4 mg cm^&minus;3<br />&nbsp;was established.</p><p>During degradation of MCPP and MCPA it was observed that the rate is higher if&nbsp;TiO₂(rutile) was applied comparing to Fe-TiO_2&nbsp;and with increasing amount of Fe^3+&nbsp;photocatalytic activity mostly decreases. When TiO₂ (anatase) doped with various amounts&nbsp;of Fe^3+&nbsp;(0.71 to 1.80 at.%) was applied for MCPP degradation, the process was much&nbsp;slower than with undoped catalyst.</p><p>Since we have not found relevant literature data on kinetics and mechanism of&nbsp;photocatalytic degradation of clopyralid, its stability in different experimental conditions&nbsp;was tested. In investigating of influences of pH (1.0&ndash;9.0) both in presence and in absence&nbsp;of daylight, in no cases decomposition was observed during seven months experiments.&nbsp;Also, the kinetics of photocatalytic degradation of clopyralid using UV and visible&nbsp;irradiation in the presence of TiO_2&nbsp;Degussa P25 and in direct photolysis by application of&nbsp;both irradiation sources was studied. It was found that the &nbsp;rate of photocatalytic&nbsp;decomposition using UV radiation was 5 times higher comparing to direct photolysis. For&nbsp;clopyralid photocatalytic monitoring a pH value of &nbsp;3.2 was chosen. In addition, in the investigated concentration range (0.5&ndash;3.0 mmol &nbsp;dm^&minus;3) the photocatalytic degradation kinetics of clopyralid in the first stage of the reaction follows approximately a pseudo-first kinetic order. In investigation of influence of catalyst concentration (0.5&ndash;8 mg cm^&minus;3) on the rate of clopyralid degradation the highest reaction rate was observed at 4 mg cm^{&minus;3&nbsp;}of catalyst concentration The apparent activation energy of the reaction being 7.74 kJ mol^&minus;1. The absence of molecular oxygen resulted in a significant decrease (about 2 times) in the rate of clopyralid photodegradation. The effect of the presence of (NH₄)₂S₂O₈, H₂O_2&nbsp;and KBrO₃, acting as electron acceptors along with molecular oxygen affects clopyralid photocatalytic degradation considerably and indifferent ways. By studying the effect of ethanol as a hydroxyl radical scavenger it was shown that the heterogeneous catalysis takes place mainly via ^&bull;OH radicals.</p><p>LC&minus;MS/MS (ESI+) monitoring of the process showed that several pyridine-containing intermediates are formed: 3,6-dichloropyridin-2-ol, 3,6-dichloro&nbsp;hydroxypyridine-2-carboxylic acid and 3,3&#39;,6,6&#39;-tetrachloro-2,4&#39;-bipyridine-2-carboxylic&nbsp;acid. Based on the identified intermediates and overall kinetic results, a probable&nbsp;photocatalytic degradation mechanism was proposed.&nbsp;</p><p>Finally, in the case of clopyralid it was established that practically no degradation&nbsp;<br />occurs in the presence of TiO_2&nbsp;(anatase) and N-TiO₂ (dry procedure) with visible light &nbsp;and&nbsp;also with TiO_2&nbsp;Degussa P25. Besides of that, by using TiO_2&nbsp;(rutile) and Fe-TiO_2&nbsp;as&nbsp;photocatalysts it was noted that increasing the concentration of Fe^3+&nbsp;from 0.13 to 1.27 at.%&nbsp;comes to increasing photodegradation rate of clopyralid. Results indicate that differences&nbsp;in molecular structure of chosen compound, influence obtained photocatalytic activity to a&nbsp;great extent.</p>

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The methodology developed in the present work, through chromatographic fingerprint by LC-DAD and Principal Component Analysis (PCA), was adequate for the chemical differentiation of Lippia alba (Mill) NE Brown accessions, considering the extraction method (infusion and maceration hydroalcoholic) and the collection season (summer and winter), allowing to evaluate the influence of these variables on the chemical composition of extracts obtained. In addition, all extracts were submitted to cytotoxic tests against two tumor cell lines, HL-60 (human leukemia) and HepG2 (human hepatocellular carcinoma), and to inhibition tests against the enzyme acetylcholinesterase (AChE) in order to evaluate the form of extraction and which access is the most promising from a pharmacological point of view. Among the extracts analyzed against tumor cells, eight of them, two from the infusion: 01IW and 02IW and six from the hydroalcoholic extraction: 02HW, 24HW, 39HW, 54HW, 01HS and 24HS, presented better cell inhibition performances against HL-60, with percentage of inhibition between 40.0 and 52.0%, suggesting that these extracts are potentially promising against this lineage. With respect to the anticholinesterase tests, all extracts studied had low AChE inhibitory effect when compared to galantamine (87.4%), highlighting only the samples 01HW (28.4%), 02HW (27.2%), 54HW (29.3%), 01HS (32.7%), 02HS (27.4%) and 24HS (30.3%). Through the analyzes performed by Nuclear Magnetic Resonance (NMR) it was possible to identify the structures of some compounds isolated from this species: flavone tricin and phenylpropanoid verbascoside/isoverbascoside. In addition, the classes of three other metabolites were proposed: two phenylpropanoid derivatives and one flavonoid diglucoside. / A metodologia desenvolvida no presente trabalho, utilizando fingerprint cromatográfico por CL-DAD e Análise de Componentes Principais (PCA), se mostrou adequado para a diferenciação química de acessos de Lippia alba (Mill) N. E. Brown, considerando o método de extração (infusão e maceração hidroalcoólica) e a época de coleta (verão e inverno), permitindo, ainda, avaliar a influência destas variáveis na composição química dos extratos obtidos. Adicionalmente, todos os extratos foram submetidos a testes citotóxicos frente a duas linhagens de células tumorais, HL-60 (leucemia humana) e HepG2 (carcinoma hepatocelular humano), e de inibição enzimática frente a acetilcolinesterase (AChE) com o intuito de avaliar qual a forma de extração e qual acesso é o mais promissor do ponto de vista farmacológico. Entre todos os extratos analisados frente as células tumorais, dois provenientes da infusão: 01II e 02II e seis da extração hidroalcoólica: 02HI, 24HI, 39HI, 54HI, 01HV e 24HV, apresentaram melhores desempenhos de inibição frente a HL-60, com percentual de inibição entre 40,0 e 52,0%, sugerindo que estes extratos são potencialmente promissores contra esta linhagem. Com relação aos testes anticolinesterásicos, todos os extratos estudados apresentaram baixo efeito inibidor da AChE quando comparados a galantamina (87,4%), com destaque para os extratos 01HI (28,4%), 02HI (27,2%), 54HI (29,3%), 01HV (32,7%), 02HV (27,4%) e 24HV (30,3%). Através das análises realizadas por Ressonância Magnética Nuclear (RMN) foi possível identificar as estruturas de alguns dos compostos isolados a partir desta espécie: a flavona tricina e o fenilpropanóide verbascosídeo/isoverbascosídeo. Além disso, foram propostas as classes de outros três metabólitos: dois derivados de fenilpropanóides e um flavonóide diglicosilado. / São Cristóvão, SE