Academic literature on the topic 'Deriváty fenolu'

ANALISIS DISINFEKTAN FENOL SECARA SIKLIK VOLTAMMETRI Pirim Setiarso*, Nita Kusumawati, Lenny Yuanita, Tukiran, Samik Jurusan Kimia FMIPA, Fakultas Matematika dan Ilmu Pengetahuan AlamUniversitas Negeri Surabaya, Jl. Ketintang, Surabaya, 60231e-mail : pirimsetiarso@unesa.ac.id ABSTRAKTelah dilakukan penelitian Analisis Disinfektan Fenol Secara Siklik Voltametri. Fenol merupakan derivat dari benzena yang salah satu atom H diganti dengan gugus OH. Fenol bersifat racun oleh karena itu, fenol digunakan sebagai disinfektan. Beberapa disifektan yang dijual dipasaran mengandung fenol dan harus memenuhi standar kesehatan.Analisis fenol dilakukan dengan siklik voltammetri menggunakan elektroda graphen oksida yang dibuat dari karbon pensil 2B. Elektrada dibuat dengan campuran graphen oksida parafin dengan perbandingan 8:2. Pengukuran fenol pada disinfektan pasaran menggunakan parameter larutan KCl 5000 ppm sebagai elektrolit pedukung, larutan buffer fosfat pH 6,5. Waktu deposisi 5 detik, dan laju pindai 0,3 mV/s.Disinfektan fenol pasaran diukur berdasarkan kurva fenol standar dengan persamaan linier Y = -0.005507-5.00823 10-5 X dengan koefisien regresi linear R = 0.989229. Berdasarkan perhitungan kurva standar didapatkan kadar fenol disinfektan pasaran merek A= 26,48 ppm; B= 38,24 ppm .

Teh (Camellia sinensis L) berpotensi besar sebagai obat dan pengawet bahan pangan karena mengandung zat antioksidan yaitu katekin dan tannin. Kedua senyawa ini merupakan derivat dari flavonoid serta telah dikenal sebagai fenol. Penelitian ini bertujuan untuk mengetahui ada tidaknya fenol dalam produk komersial teh hijau serta mengukur kadar fenol totalnya menggunakan spektofotometer UV-Vis. Sampel yang digunakan adalah 5 macam produk komersial teh hijau yakni (1) Sampel A ; (2) Sampel B ; (3) Sampel C ; (4) Sampel D ; dan (5) Sampel E. Sampel ini diambil secara acak (random) dari berbagai jenis teh hijau produk komersial yang ada di kota Mataram. Berdasarkan hasil penelitian, rata-rata kadar fenol total dari kelima jenis produk teh hijau berturut-turut adalah 4,618 gr/kg; 4,600 gr/kg; 5,012; 4,906; 4,408. Hasil uji statistik dengan ANAVA satu arah menunjukkan bahwa kadar fenol total dari kelima jenis produk teh tersebut tidak berbeda nyata pada α = 5%, yang ditunjukkan oleh Fhitung = 2,943 yang lebih kecil dari Ftabel (5%) = 3,48. Hal ini disebabkan oleh proses pengolahan teh hijau secara umum relatif sama di setiap perusahaan dan varietas teh yang digunakan sebagai produk juga sama yaitu varietas Assamica.

<p>ABSTRAK</p><p>Banyak tanaman yang dilaporkan memiliki kandungan senyawabahan aktif antioksidan dan antibakteri. Salah satu tanaman Indonesia yangmemiliki aktivitas ini adalah gambir (Uncaria gambir). Pada penelitian ini,ekstrak etanol daun gambir diubah menjadi derivat metilnya untukmembuatnya lebih larut dalam lemak dan diamati pengaruh derivatisasitersebut terhadap aktivitas antioksidan di laboratorium kimia organik danpengujian aktivitas antibakteri di laboratorium mikrobiologi UniversitasPadjadjaran. Penelitian ini dilaksanakan di laboratorium Kimia OrganikJurusan Kimia dan laboratorium Mikrobiologi Jurusan Biologi UniversitasPadjadjaran dari bulan Desember 2004 - Juli 2005. Ekstrak gambirdimetilasi menggunakan dimetil sulfat (DMS) dan dimurnikanmenggunakan kromatografi kolom dengan pelarut bergradien (kloroform :metanol = 99:1 ; 98:2 ; 95:5 ; 80:20 ; 70:30; dan 50:50 v/v) dan kemudianmenggunakan kloroform : metanol = 99 : 1 v/v. Aktivitas antioksidanmenunjukkan penurunan yang tampak dari peningkatan, yaitu : IC 50 13,41ppm untuk ekstrak etanol menjadi 121,81 ppm untuk hasil metilasi.Aktivitas antibakteri juga menunjukkan penurunan setelah dimetilasikarena adanya penurunan diameter hambat pertumbuhan bakteri. Duaisolat (isolat 1 dan 2) yang diperoleh dari hasil pemurnian dikarakterisasimenggunakan spektrofotometer UV-Visible dan FT-IR. Hasil yangdiperoleh mengindikasikan adanya senyawa fenolik yang ditunjukkan olehregang –OH pada 3445 dan 3448 cm -1 dan regang CH aromatik pada 3010dan 3030 cm -1 . Isolat 1 memiliki aktivitas antioksidan dan antibakteri yanglebih tinggi dibandingkan isolat 2.</p><p>Kata kunci : Uncaria gambir, derivat metil, antibakteri dan aktivitasantioksidan</p><p>ABSTRACT</p><p>The antioxidant and antibacterial activities of ethanolextract of gambir leaves (Uncaria gambir)</p><p>There are many plants in Indonesia reported to contain antioxidantand antibacterial substances. One of them having these activities is gambir(Uncaria gambir). In this research, ethanol extract of gambir leaves waschanged into its methyl derivate in order to make it more soluble in fats.The effect of the derivatization on antioxidant activity was observed atorganic chemistry laboratory and antibacterial activity was observed atmicrobiology laboratory of the Padjadjaran University. This research wascarried out in December 2004 to July 2005. Gambir extract wasmethylized using dimethylsulphate (DMS) and then purified usingcoloumn chromatography with gradient solvents (chloroform : methanol =99:1; 98:2; 50:50; 80:20; 70:30; and 50:50 v/v), and then with chloroform :methanol = 99:1 v/v. The antioxidant activity showed a decrease indicatedby an increase of IC 50 from 13.41 ppm for ethanolic extract to become121.81 ppm for the methylated compounds. The antibacterial activity alsoshowed a decrease after methylization due to the decrease of inhibitiondiameter of bacteria growth. Two isolates (isolate 1 and 2) obtained fromthe purification steps were characterized using UV-Visiblespectrophotometer and FT-IR. The results indicated the existence ofphenolic compunds showed by -OH stretching in 3,445 and 3,448 cm -1 ;and CH aromatic stretching in 3,010 and 3,030 cm -1 . Isolate 1 was higherin antioxidant and antibacterial activities than isolate 2.</p><p>Key words : Uncaria gambir, methyl derivative, antibacterial, antioxidantactivities</p>

Abstract: Induction of general anesthesia is an action to cause an unconsciousness state of a patient before commencing a surgical operation. Propofol is a phenol derivative which is widely used as an intravenous anesthetic drug. A venous injection of propofol causes pain in the injection site. Lidocaine can reduce pain the on the injection site of propofol. This study aimed to compare the incidence of patients who still experienced pain on the injection site of propofol although had been administered lidocaine 0.50 mg / kg BW or lidocaine 0.70 mg / kg BW. This was an experimental study conducted at the Central Surgical Installation (IBS) and the emergency operative room at Prof Dr. R. D. Kandou General Hospital Manado from November 2012 to December 2012. The result showed that in the lidocaine 0.5 mg/kg BW group there were 8.3% samples with pain and 91.7% without pain. In the lidocaine 0.7% group, there were no samples (0%) with pain hence 100% without pain. The chi-square test showed a P = 0.307. Conclusion: Although not statistically significant, administration of lidocain 0.70 mg/kg BW was more effective in reduction of pain at the injection sites of propofol than that of lidocain 0.50 mg/kg BW. Keywords: propofol, lidocaine Abstrak: Induksi anestesia umum ialah tindakan untuk membuat pasien menjadi tidak sadar sehingga memungkinkan dimulainya tindakan pembedahan. Propofol merupakan derivat fenol yang banyak dipakai sebagai obat anestetik intravena. Penyuntikan propofol lewat vena menyebabkan rasa nyeri pada tempat penyuntikan. Pemberian lidokain merupakan salah satu cara untuk mengurangi rasa nyeri pada penyuntikan propofol. Penelitian ini bertujuan untuk membandingkan insiden pasien yang mengalami nyeri saat penyuntikan propofol kelompok lidokain 0,50 mg/kgBB dan kelompok lidokain 0,70 mg/kgBB. Penelitian ini merupakan penelitian eksperimental. Penelitian dilaksanakan di Instalasi Bedah Sentral (IBS) dan ruang OK CITO RSUP Prof. Dr. R. D. Kandou Manado pada bulan November 2012 sampai Desember 2012. Hasil penelitian menunjukkan bahwa jumlah proporsi sampel yang nyeri pada kelompok lidokain 0,5 mg/kg yaitu 8,3% sedangkan yang tidak nyeri 91,7%. Pada kelompok lidokain 0,7 mg/kg tidak dijumpai sampel dengan keluhan nyeri (0%), yang berarti terdapat 100% sampel yang tidak nyeri. Uji statistik dengan chi-square menunjukkan nilai P = 0,307. Simpulan: Walaupun tidak bermakna secara statistik, pemberian lidokain 0,70 mg/kg lebih efektif menurunkan nyeri pada tempat penyuntikan propofol dibandingkan dengan lidokain 0,50 mg/kg. Kata kunci : propofol, lidokain

U  radu  je  ispitan  uticaj  amida  kao  modela  AOM-a (Algalne organske materije)  na adsorpciju nitrofenola iz vodene  sredine  na  aktivnom  uglju.  Istraţivanje  se sastojalo  iz  tri  faze:  ispitivanje  uticaja  karateristika amida  na  adsorpciju  nitrofenola,  ispitivanje  uticaja granulacije na adsorpciju nitrofenola u prisustvu amida i ispitvanje karakterisitka samih nitrofenola na adsorpciju u  prisustvu  amida.  Pre  ispitivanja  adsorpcije  u dvokomponentnim  sistemima  ispitana  je  adsorpcija jednokomponentnih  sistema  4-nitrofenola,  2,4-dinitrofenola  i  2,4,6-trinitrofenola,  kao  i  amida  Nmetilbenzamid,  nikotinamida  i  N-benzilbenzamida  na komercijalnim  aktivnim  ugljevima  NORIT  SA2  i  dve granulacije  aktivnog  uglja  DARCO.  Aktivni  ugljevi  su ispitani  metodom  FTIR  spektroskopije,  SEM  analizom, analizom  površine  adsorpcijom  azota  na  niskoj temperaturi  i  određivanjem  taĉke  nultog  naelektrisanja. Urađena  je  geometrijska  optimizacija  modela  molekula ispitivanih nitrofenola i amida i izraĉunati su molekulski parametri.  Uticaj  amida  kao  modela  AOM-a  je  ispitan korišćenjem  razliĉitih  ravnotežnih  i  difuzionih adsorpcionih  modela.  Kao  kriterijum  za  određivanje najsporije  adsorpcione  faze  korišćen  je  Biotov  broj.Adsorpcioni  parametri  dobijeni  u  eksperimentima  sa dvokomponentnim  sistemima  su  upoređivani  sa parametrima dobijenim za adsorpciju samih nitrofenola.
In this research influence of selected amides, as a model of  AOM  (Algal  organic  matter),  on  adsorption  of nitrophenols  from  water  on  activated  carbon  has  beeninvestigated.  Research  is  divided  in  three  phases: investigation  of  influence  of  amide  molecule characteristics  on  the  adsorption  of  nitrophenols, investigation  of  granulation  influence  on  nitrophenol adsorption in  the  presence of amide and investigation of nitrophenol characteristics that can influence adsorption in  the  presence  of  amides.  Adsorption  of  nitrophenols and  amides  in  single- component  systems  has  also  been carried  out.  Adsorption  kinetics  of  4-nitrophenol,  2,4-dinitrophenol,  2,4,6-trinitrophenol,  N-methylbenzamide,nicotinamide  and  N-benzylbenzamide  has  also  been investigated. Commercial activated carbons NORIT SA2 and  two  granulations  of  DARCO  were  used.  Activated carbons  were  characterized  using  FTIR  spectroscopy, SEM  analysis,  internal  surface  analysis  using  nitrogen adsorption  on  low  temperature  and  determination  of point  of  zero  charge.  Geometry  optimization  of nitrophenol  and  amide  molecules  has  been  carried  out and different molecular parameters have been calculated. Influence  of  amides  as  AOM  model  has  been investigated by using diffusion and equilibrium models. Biot number has been obtained  in order to establish the limiting  step  in  adsorption  process.   Adsorption parameters  obtained  in  two-component  adsorption systems  were  compared  to  parameters  obtained  for adsorption of nitrophenols alone.

The study deals with the synthesis and biological activity of 4 different antitumours: Tetrahydro-[1,4]-dioxanisoquinolines, combretastatin A-4, dioxancarbazoles and resveratrol analogues. This study describes the synthesis strategy and multi-step synthesis of these potential antitumour compounds. Various tetrahydroisoquinolines were synthesized, five of which were biologically tested and have a promising K-Ras inhibition activity. Two of them show a high antiangiogenesis activity, one of which also presents antiosteoporosis properties. Two pirazolone derivatives were synthetized and biologically tested, one of which shows a very high K-Ras inhibition, antiangiogenesis and antiosteoporosis activity and inhibits the G2 cell cycle phases and subphases. Two azoledione combretastatin A-4 derivatives were also synthesized and will be biologically tested. Two dioxancarbazoles were prepared and biologically tested, one of which shows a high K-Ras and angiogenesis inhibition. Finally, four resveratrol analogues were synthesized and biologically tested. Their biological results show a moderate and selective K-Ras inhibition on the studied cell lines. In the future, the rest of the synthesized compounds are to be biologically tested. Further CDKs and topoisomerase II inhibition trials as well as toxicity studies will be carried out.
El estudio trata de la síntesis y la actividad biológica de 4 antitumorales diferentes: Análogos de tetrahidro-[1,4]-dioxanisoquinolinas, de combretastatina A-4, de dioxancarbazol y del resveratrol. El estudio describe la estrategia sintética y la síntesis multietapas de esos compuestos potencialmente antitumorales. Varias tetrahidroisoquinolinas fueron sintetizadas, cinco de ellas fueron probadas biológicamente y presentan una actividad de inhibición de la proteína K-Ras prometedora. Dos de esos compuestos presentan una actividad anti antiangiogénica elevada y uno presenta actividades de antiosteoporosis. Dos derivados de pirazolona fueron sintetizados y probados biológicamente, uno de ellos muestra una inhibición muy elevada de la K-Ras, de antiangiogénesis y de antiosteoporosis e inhibe la fase G2 del ciclo celular y sus subfases. Se han preparado dos derivados de azolediona combretastatina A-4 que se evaluarán biológicamente. Se sintetizaron dos derivados de dioxancarbazol, uno de ellos presenta una actividad alta de la K-Ras y de antiangiogénesis. Finalmente, se prepararon y evaluaron biológicamente cuatros análogos del resveratrol. Los resultados biológicos muestran una inhibición moderada y selectiva de la K-ras en las líneas celulares estudiadas. Próximamente, el resto de los compuestos sintetizados se evaluarán biológicamente. Ensayos adicionales de inhibición de CDKs, de topoisomerasa II y de toxicidad serán llevados a cabo.

Supportato da una crescente consapevolezza ambientale, il glicerolo carbonato ha guadagnato molto interesse negli ultimi 20 anni grazie alla sua versatile reattività e alla possibilità di valorizzare il glicerolo co-prodotto nella sintesi di biodiesel. Sono stati identificati numerosi percorsi di sintesi per questa molecola, alcuni dei quali molto promettenti e sul punto di essere applicati su scala industriale. Qui, riportiamo uno studio volto a valorizzare il glicerol carbonato come intermedio chimico, in particolare come agente alchilante innovativo del fenolo al fine di sintetizzare aril gliceril eteri. Queste molecole trovano importanti applicazioni come intermedi chiave per la sintesi di un'ampia classe di farmaci e agenti terapeutici. Abbiamo effettuato la reazione in massa senza l’impiego di solventi, con una miscela di glicerolo carbonato e fenolo, in presenza di un catalizzatore basico (omogeneo o eterogeneo). È interessante notare come, nelle condizioni ottimizzate, sia stato possibile ottenere un'alta conversione dei reagenti, unita ad una elevata resa e selettività negli aril gliceril eteri voluti, già dopo poche ore di reazione. Inoltre, è stato proposto un approccio multi-step per la sintesi selettiva di difenil gliceril eteri.

2-Phenoxyethanol (ethylene glycol monophenyl ether) is used as solvent for cellulose acetate, dyes, inks, and resins; it is a synthetic intermediate in the production of plasticizers, pharmaceuticals, and fragrances. Phenoxyethanol is obtained industrially by reaction of phenol with ethylene oxide, in the presence of an homogeneous alkaline catalyst, typically sodium hydroxide. The yield is not higher than 95-96%, because of the formation of polyethoxylated compounds. However, the product obtained may not be acceptable for use in cosmetic preparations and fragrance formulations, due to presence of a pungent “metallic” odor which masks the pleasant odor of the ether, deriving from residual traces of the metallic catalyst. Here we report a study aimed at using ethylene carbonate in place of ethylene oxide as the reactant for phenoxyethanol synthesis; the use of carbonates as green nucleophilic reactants is an important issue in the context of a modern and sustainable chemical industry. Moreover, in the aim of developing a process which might adhere the principles of Green Chemistry, we avoided the use of solvents, and used heterogeneous basic catalysts. We carried out the reaction by using various molar ratios between phenol and ethylene carbonate, at temperatures ranging between 180 and 240°C, with a Na-mordenite catalyst. Under specific conditions, it was possible to obtain total phenol conversion with >99% yield to phenoxyethanol in few hours reaction time, using a moderate excess of ethylene carbonate. Similar results, but with longer reaction times, were obtained using a stoichiometric feed ratio of reactants. One important issue of the research was finding conditions under which the leaching of Na was avoided, and the catalyst could be separated and reused for several reaction batches.

Tot i que el camp de l'acoblament creuat ha desenvolupat increïbles avenços, la gran majoria de processos encara es basen en l'ús d'halurs d'aril. No obstant, aquest tipus d’electròfils presenten una toxicitat intrínseca i, al mateix temps, la seva síntesis resulta tediosa, especialment quan es tracta d'halurs d'aril altament funcionalitzats. A causa d'això, la comunitat sintètica s'ha bolcat en la recerca d'alternatives a l'ús d'halurs d'aril en química d'acoblament creuat. Grans esforços s'han desenvolupat en la última dècada per implementar els derivats del fenol en aquest tipus de transformacions a causa de l'abundància natural i comercial d'aquests compostos i a la seva baixa toxicitat en comparació amb els organohalurs. No obstant, l'alta energia d'activació necessària per trencar els enllaços C-O ha limitat considerablement l'ús de derivats de fenol en reaccions d’acoblament creuat, sobretot si es tracta d'éters de metil. Actualment la gran majoria de mètodes basats en aquesta família d’electròfils s'utilitzen en la formació d'enllaços C-C. Altrament, gairebé no existeixen tècniques per obtenir enllaços Cheteroàtom probablement a causa de la baixa reactivitat dels nucleòfils, on la densitat de càrrega negativa resideix en un heteroàtom. La present tesi doctoral s'ha centrat en el desenvolupament de noves metodologies per a la creació d'enllaços de tipus C-heteroàtom mitjançant l’activació catalítica d'enllaços C-O amb complexes de Ni. S'han descrit nous mètodes de sililació i borilació d'ésters i metil éters d’aril i benzil. Aquests mètodes suposen una via alternativa per a la síntesis de silans i boronats, els quals són intermedis de gran utilitat en síntesis orgànica. A més, el descobriment d'unes condicions totalment inusuals per activar enllaços de tipus C-OMe ha obert noves perspectives sobre la reactivitat d'aquest tipus d'enllaços i, alhora, ha suggerit l'existència de nous mecanismes d'activació.
A pesar de que el campo del acoplamiento cruzado ha desarrollado increíbles avances, la gran mayoría de procesos todavía se basa en el uso de halogenuros de arilo. Sin embargo, este tipo de electrófilos presentan una toxicidad intrínseca y, a su vez, su síntesis resulta tediosa, especialmente cuando se trata de halogenuros de arilo altamente funcionalizados. Debido a ello, la comunidad sintética se ha volcado en la búsqueda de alternativas al uso de halogenuros de arilo en química de acoplamiento cruzado. Un gran esfuerzo se ha desarrollado en la última década para implementar los derivados del fenol en este tipo de transformacions debido a la abundancia natural y comercial de dichos compuestos y a su baja toxicidad en comparación con los organohalogenuros. Sin embargo, la alta energía de activación necesaría para romper los enlaces C-O ha limitado considerablemenete el uso de derivados del fenol en reacciones de acomplamineto cruzado, sobre todo si se trata de éteres de metilo. Actualmente la gran mayoría de métodos basados en esta familia de electrófilos se utilizan en la formación de enlaces C-C. De lo contrario, apenas existen técnicas para obtener enlaces C-heteroátomo probablemente debido a la baja reactividad de los nucleófilos donde la densidad de carga negativa reside en un heteroátomo. La presente tesis docotoral se ha centrado en el desarrollo de nuevas metodologías para la creación de enlaces de tipo C-heteroatomo mediante la activción catalítica de enlaces C-O con complejos de Ni. Se han descrito novedosos métodos de sililación y borilación de ésteres y metil éteres de arilo y bencilo. Dichos métodos suponen una via alternativa para la síntesis de silanos y boronatos, los cuales son intermedios de gran utilidad en síntesis orgánica. Además, el descubrimiento de unas condiciones totalmente inusuales para activar enlaces de tipo C-OMe ha abierto nuevas perspectivas sobre la reactividad de este tipo de enlaces y, a la vez, ha sugerido la existencia de nuevos mecanismos de activación.
While the field of cross-coupling has reached remarkable levels of sophistication, the vast majority of processes are still being conducted with organic halide counterparts. Drawbacks associated to their toxicity and the limited accessibility of densely functionalized aryl halides have prompted chemists to develop powerful, yet practical, alternatives. Among these, the utilization of phenol derivatives as coupling partners via C-O bond cleavage would be particularly rewarding due to their readily availability and benign nature. However, the high activation energy required for effecting C–O bond cleavage has become a daunting challenge when devising catalytic techniques using phenol derivatives, specially always-elusive aryl methyl ethers. At present, the vast majority of cross-coupling reactions using phenol derivatives remains confined to C–C bond formation, whereas the formation of C-heteroatom bonds has been poorly studied, likely due to the less reactivity of heteroatom-based nucleophiles. This doctoral thesis has focused on the development of new methodologies for forging C-heteroatom bonds via Ni-catalyzed C-O bond cleavage. It has been described new protocols for the silylation and borylation of aryl and benzyl esters and methyl ethers. These methodologies can be used as useful alternatives towards the synthesis of aryl and benzyl silanes and boronates, incredible important intermediates in organic synthesis. Furthermore, the discovery of unusual, yet surprising, conditions for the cleavage of C-OMe bonds have opened up new vistas towards the reactivity of aryl and benzyl methyls ethers while suggesting new activation pathways.

Mikroplastika  je  sveprisutna  u  vodenom  ekosistemu  pri  čemu  se  čestoističe značaj ispitivanja njihovog uticaja na ponašanje drugih jedinjenja u vodi.Pod pojmom mikroplastika podrazumevaju se plastične čestice manje od 5 mm.Imajući u vidu potrebu za unapređenjem znanja o štetnom uticaju mikroplastikeu životnoj sredini u ovom radu sproveden je set eksperimenata u kom je ispitivanmehanizam  interakcija  koje  se  uspostavljaju  prilikom  adsorpcije  hlorovanihfenola,  derivata  benzena  i  policikličnih  aromatičnih  ugljovodonika  na mikroplastici  u  vodenom  matriksu.  Kako  bi  se  što  detaljnije  razumeo  uticaj mikroplastike  i  osobina  vodenog  matriksa  na  ponašanje  organskih  polutanata, laboratorijska ispitivanja su sprovedena u sintetičkom i realnom vodenommatriksu.  Takođe  je  sprovedena  optimizacija  izolovanja  i  karakterizacije mikroplastike iz kozmetičkih sredstava u cilju procene uticaja osobina primarne mikroplastike na uspostavljanje interakcija sa organskim polutantima. Na  osnovu  dobijenih  rezultata  istraživanja  može  se  zaključiti  da  se optimalna metoda izolovanja mikroplastike iz kozmetičkih sredstava zasniva na dodatnom  tretiranju  osušenog  materijala  30%  vodonik-peroksidom,  nakon ekstrakcije  sredstva  u  destilovanoj  vodi,  u  cilju  dobijanja  čistijih  uzoraka mikroplastike. Promena brzine mešanja ima znčajan uticaj na promenu stepena adsorpcije ispitivanih grupa organskih jedinjenja.  Uticaj se ogleda u povećanju stepena adsorpcije sa porastom brzine mešanja, a maksimalni procenat adsorpcije postignut  je  pri  brzini  mešanja  od  150  o/min.  Dodatno,  disperzija  praškastih materijala u vodi nema značajan uticaj na promenu stepena adsorpcije hlorovanih fenola,  derivata  benzena  i  policikličnih  aromatičnih  ugljovodonika  na mikroplastici.Ravnotežno  stanje  između  koncentracije  hlorovanih  fenola,  derivatabenzena  i  policikličnih  aromatičnih  ugljovodonika  u  vodi  i  odabranih predstavnika  mikroplastike  (PEp,  PE_PCPs_1,  PE_PCPs_2,  PEg,  PET,  PP  i PLA) uspostavlja se nakon 24 i 48 h kontakta u zavisnosti od vrste jedinjenja. Na promenu  adsorpcionog  afiniteta  hlorovanih  fenola,  derivata  benzena  i policikličnih aromatičnih ugljovodonika prema mikroplastici utiču kako fizičkohemijske  osobine  jedinjenja  tako  i  karakteristike  mikroplastike.  Na  osnovu kinetičkih  eksperimenata, najveći adsorpcioni afinitet ka mikroplastici  ispoljili su  derivati  benzena  (qt=103-350  µg/g),  dok  je  najmanji  uočen  kod  hlorovanih fenola  (qt=25-225  µg/g).  Dobijeni  rezultati  adsorpcije  derivata  benzena  na ispitivanim  česticama  mikroplastike  takođe  su  ukazali  na  veći  afinitet  ovih jedinjenja  ka  mikroplastici,  u  poređenju  sa  jedinjenjima  iz  grupe  policikličnih aromatičnih  ugljovodonika  i  hlorovanih  fenola  sličnih  logKow  vrednosti. Dodatno,  uticaj  vodenog  matriksa  na  adsorpciju  hlorovanih  fenola,  derivata benzena  i  policikličnih  aromatičnih  ugljovodonika  na  mikroplastici  zavisi  od same grupe jedinjenja kao i od vrste mikroplastike pri čemu je najmanje izražen u  slučaju  ispitivanih  policikličnih  aromatičnih  ugljovodonika,  a  najviše  kod hlorovanih fenola.Visoke  vrednosti  koeficijenta  determinacije  kinetičkog  modela  pseudodrugog  reda  za  adsorpciju  hlorovanih  fenola,  derivata  benzena  i  policikličnih aromatičnih ugljovodonika na čestice mikroplastike ukazjuju da je hemisorpcija mogući  mehanizam.  Pored  visokih  vrednosti  koeficijenata  determinacije  u slučaju svih odabranih organskih jedninjenja dobijena konstanta brzine drugog reda  bila  je  manja  od  po četne  brzine  adsorpcije  što  ukazuje  na  znatno  brže odvijanje  adsorpcije  pri  kraćim  vremenima  kontakta  (12-24  h)  nakon  čega  jedolazilo do usporavanja procesa adsorpcije.Mehanizam adsorpcije hlorovanih fenola, derivata benzena i policikličnih aromatičnih ugljovodonika  ispitivan  je primenom Freundlich-ovog, Langmuirovog,  Redlich-Peterson-ovog  i  Dubinine-Radusckevich-evog  adsorpcionog modela. Vrednosti Freundlich-ovog eksponenta za adsorpciju hlorovanih fenola, derivata benzena i  policikličnih aromatičnih ugljovodonika bile su manje od 1,što ukazuje na to da je slobodna energije adsorpcije na mikroplastci opadala sa povećanjem  inicijalne  koncetracije  ispitivanih  polutanata.  Vrednosti maksimalnog adsorpcionog kapaciteta dobijene za  adsorpcione procese PAH  na česticama mikroplastike bile su u opsegu od 29,7-2596,5 µg/g. Visoke vrednosti maksimalnih adsorpcionih kapaciteta dobijene su takođe za adsorpciju derivata benzena na ispitivanim vrstama mikroplastike  39,3-2010,1 µg/g. S druge strane, uočeno  je  različito  adsorpciono  ponšanje  hlorovanih  fenola  u  zavisnosti  od vodenog metriksa u kom su eksperimenti sprovedeni pri čemu su  qmax  vrednosti iznosile 20,00-205,6 µg/g. Značajan uticaj  pH vrednosti vodenog matriksa  utvrđen je  za adsorpciju hlorovanih  fenola  na  mikroplastici,  dok  u  slučaju  derivata  benzena  i  PAH promena pH vrednosti vodenog matriksa nije pokazala značajan uticaj. Rezultati dobijeni  za  adsorpciju  hlorovanih  fenola  na  mikroplastici  ukazuju  na  nižu tendenciju  ka  formiranju  interakcija  hlorovanih  fenola  sa  česticama mikroplastike pri pH 4 i pH 10, pri čemu se stepen adsorpcije kretao u opsegu od 8-35% i 15-35%, respektivno, u odnosu na pH 7 (55-65%). Najniži  adsorpcioni  afinitet  uočava  se  pri  adsorpciji  ispitivanih  grupa jedinjenja na PLA. Može se pretpostaviti da će se organski polutanti,   ukoliko ova vrsta mikroplastike dospe u vodene sisteme, slabo vezivati na ovaj materijal pri čemu će značajno manje uticati na njihov trasport kroz životnu sredinu, u odnosuna druge ispitivane vrste mikroplastike. Na  osnovu  dobijenih  rezultata  istraživanja  može  se  zaključiti  da  na adsorpciju ispitivanih grupa organskih jedinjenja i mikroplastike značajan uticaj imaju  fizičko-hemijske  osobine  ispitivanih  jedinjenja  kao  što  su  kiselinska konstanta, veličina molekula, hidrofobnost, stukturni raspored i dr. Pored toga, karakteristike vodenog matriksa, među kojima je najvažnija pH vrednost, imaju značajan  uticaj  na  adsorpcioni  afinitet  jedinjenja  ka  mikroplastici.  Dodatno,struktura  i  poreklo  polimera  ima  veliki  uticaj  na  formiranje  interakcija  saispitivanim grupama organskih polutanata. Dobijeni rezultati takođe ukazuju nanemogućnost  određivanje  unifomnog  mehanizma  adsorpcije  organskihjedinjenja na česticama mikroplastike u vodi.
Microplastics  are  ubiquitous  in  aquatic  ecosystems,  so  it  is  essential  to study their  impact on the behaviour of other compounds which are commonly present in water. The term microplastics refers to all plastic particles smaller than 5 mm. In order  to address knowledge gaps relating to the potential harmful effects of microplastics in the environment, the experiments conducted during this thesis were designed to investigate the adsorption mechanism of chlorinated phenols, benzene derivatives, and polycyclic aromatic hydrocarbons on microplastics in water.  To  provide  a  more  detailed  understanding  of  the  influence  of  different water  matrices  on  adsorption  properties  of  microplastics,  experiments  were conducted in both synthetic and real water matrices. In the course of this work, methods were optimised for the isolation and characterization of microplastifrom personal care products, in order to allow investigation  of the influence of the  properties  of  primary  microplastics  on  their  interactions  with  organic pollutants.Base on the obtained results, it can be concluded that the optimal method of isolating microplastics from personal care products is based  on treating already dried  material  with  30%  hydrogen  peroxide,  after  extraction  of  the  agent  in distilled water, in order to obtain cleaner microplastic samples. The mixing rate was  found  to  have  a  significant  effect  on  the  degree  of  adsorption  of  the investigated  organic  compounds.  Increasing  the  mixing  speed  led  to  a  higherdegree  of  adsorption,  with  the  maximum  adsorption  percentage  reached  at  amixing speed of 150 rpm. In addition, the dispersion of powdered materials in the  water  had  no  significant  effect  on the  degree  of  adsorption  of  chlorinated phenols,  benzene  derivatives,  and  polycyclic  aromatic  hydrocarbons  on microplastics.The  adsorption  equilibrium  between  the  concentration  of  chlorinated phenols,  benzene derivatives and polycyclic aromatic hydrocarbons in water and selected types of microplastics (PEp, PE_PCPs_1, PE_PCPs_2, PEg, PET, PP, and  PLA) was established after 24 and 48 h of contact time, depending on the selected  group  of  organic  pollutants.  The  adsorption  affinity  of  chlorinated phenols,  benzene  derivatives,  and  polycyclic  aromatic  hydrocarbons  towards microplastics  was  influenced  by  both  the  physicochemical  properties  of  the compounds  and  the  characteristics  of  the  microplastics.  Based  on  the  kinetic experiments,  the  highest  adsorption  affinity  for  microplastics  was  shown  by benzene derivatives (qt=103-350 µg/g), while the lowest was  observed during the adsorption of chlorinated phenols (qt=25-225 µg/g). Benzene derivatives showed higher  adsorption  affinities  for  the  selected  microplastic  particles  than  the polycyclic  aromatic  hydrocarbons  and    chlorinated  phenols  which  had  similar logKow  values. The influence of the water matrix on adsorption of chlorinated phenols,  benzene  derivatives,  and  polycyclic  aromatic  hydrocarbons  on microplastics  depended  on  the  specific  functional  groups  of  the  investigated compounds as well as on the type of microplastics. Water matrix had little impact on  the  adsorption  of  polycyclic  aromatic  hydrocarbons  on  microplastics  but greatly impacted the adsorption of chlorinated phenols. Fitting the pseudo-second order kinetic  model to the  adsorption data of chlorinated phenols, benzene derivatives, and polycyclic aromatic hydrocarbons on microplastic particles resulted in high correlation coefficients, indicating that chemisorption  is  the  likely  adsorption  mechanism.  In  addition  to  the  high correlation coefficients obtained for all the organic pollutants investigated, the pseudo-second order rate constants obtained were lower than the initiaadsorption rate, indicating significantly faster adsorption at shorter contact times (12-24 h), with adsorption slowing down as equilibrium was reached.The adsorption mechanism of chlorinated phenols, benzene derivatives,and  polycyclic  aromatic  hydrocarbons  was  investigated  using Freundlich,Langmuir,  Redlich-Peterson,  Dubinine-Radusckevich,  and  Temkin  adsorption models.  The  Freundlich  exponent  values  for  the  adsorption  of  chlorinated phenols, benzene  derivatives, and polycyclic  aromatic  hydrocarbons were  less than 1 which indicates that the free energy of adsorption of these compounds on microplastics  decreases  as  the  initial  concentration  increases.  The  maximum adsorption capacities of PAHs on microplastic particles were in the range of 29.7-2596.5  µg/g.  High  maximum  adsorption  capacities  were  also obtained  for the adsorption  of  benzene  derivatives  on  the  tested  types  of  microplastics:  39.3-2010.1  µg/g.  The  chlorinated  phenols  behaved  differently,  and  were  more effected by the water matrix, with qmax values in  the range 20.00-205.6 µg/g. The pH of the water matrix was found to have a significant effect on the adsorption  of  chlorinated  phenols  on  microplastics,  whereas  in  the  case  of benzene  derivatives  and  polycyclic  aromatic  hydrocarbons,  the  degree  ofadsorption  was  largely  independent  of  the  water  pH.  For  the  adsorption  of chlorinated  phenols  on  microplastics,  neutral  pH  conditions  resulted  in  the greatest degrees of adsorption (55-65% at pH 7), while adsorption was inhibited under acidic (8-35% at pH 4) and basic (15-35% at pH 10) conditions. The microplastic type with the lowest observed adsorption affinities was PLA. It can be thus be assumed that in the event that this type of microplastic enters water systems, organic pollutants will only adsorb weakly to this material, such  that  it  will  have  significantly  less  impact  on  the  transport  of  the se compounds through the environment, than the other tested  types of microplastics. The results obtained in this research demonstrate that the adsorption of the selected  groups  of  organic  pollutants  on  the  microplastics  investigated  is significantly  controlled  by  the  physicochemical  properties  of  the  tested compounds, such as the dissociation constant, molecule  size, hydrophobicity,structural properties, etc. In addition, the characteristics of the water matrix play an important role in controlling adsorption of organic pollutants on microplastic, especially the water pH. In addition, the structure and aging of the polymers had a major influence  on their interactions with the selected organic pollutants. The obtained  results  also  demonstrate  the  difficulty  in  determining  a  uniform mechanism  of  adsorption  between  the  various  organic  compounds  and microplastic particles in water.

This thesis is devoted to the study of electrochemical oxidation of meta-substituted phenolic substances on a boron-doped diamond electrode. In the first phase, it was studied the effect of pH on their electrochemical oxidation by the methods of classical "direct current" voltammetry (DCV) and differential pulse voltammetry (DPV). The study was performed on three types of boron doped diamond (BDD) surfaces: polished, anodic and cathodically activated. In the second phase, attention was paid to the Hammett correlation to study the effect of the substituent on the potential of electrochemical oxidation of selected phenolic compounds. Among the substituents studied were (-H, -CH3, -OCH3, -(CH2)2COOH, -COOH a -NO2). In general, the oxidation potentials were lower in the basic medium than in the acidic medium on all studied surfaces. An exception was the studied phenolic acids, which could not be detected in an alkaline medium on the O-terminated BDD, probably due to electrostatic repulsion between the partially negative electrode surface and the acid dianion. The highest correlation coefficient for the dependence composed of all studied phenols was obtained for the polished and H-terminated surface at pH 11, ie the dissociated form of phenolic substances. The high electron density leads to easy...

The aim of this thesis is the study of electrochemical oxidation of para-substituted phenol derivates using cyclic voltammetry (CV) and ,,direct current" voltammetry (DCV) on boron-doped diamond electrode (BDD) and comparison with some analogous meta-substituted compounds. Among the studied substances were p-cresol, 4-methoxyphenol, 4-hydroxybenzoic acid, 3-(4-hydroxyphenyl)propionic acid, 4-nitrophenol, 4-chlorophenol and 3-(trifluoromethyl)phenol. The oxidation of the analytes was performed in an acidic (pH 2,0) and basic (pH 11,0) Britton-Robinson buffer on mechanically polished, oxidated and hydrogenated surfaces. Another subject of the thesis is to analyze the influence of different substituents, characterized by the Hammett constant, on the oxidation potential of selected phenols. They are oxidized at more positive redox potentials in acidic media, than in basic media, where they are dissociated. The oxidation on the polished and hydrogenated surfaces were similar, whereas were shifted to higher values on the oxidated surface. Further, the signal intensity decreased on the oxidated one, and the oxidation of phenols was not recognizable in basic media. The passivation of the electrode was less significant in pH 2,0 buffer. The best result of Hammett correlation was achieved on a polished and...