Sorbenti u hromatografiji na tankom sloju

Thin-layer chromatography (TLC) is a simple, rapid, sensitive and inexpensive analytical method for the separation and identification of various substances. During the chromatographic process components to be separated are distributed between two phases one of which is stationary while the other is mobile phase. The mobile phase in TLC is a liquid, containing a single solvent or a mixture of solvents. The stationary phase is a porous solid, known as the sorbent, which is situated as a thin layer on the surface of a flat plate. Numerous inorganic and organic sorbents are available, such is silica, alumina, cellulose, polyamides, chemically modified sorbents. In this paper some commonly used sorbents are described.Hromatografija na tankom sloju, zbog svoje jednostavnosti, brzine izvođenja i niske cene potrebne opreme, predstavlja široko primenjivanu metodu za odvajanje, dokazivanje i određivanje najrazličitijih organskih i neorganskih supstanci. Pored toga, ova metoda se koristi i za predviđanje ponašanja supstanci pri uslovima tečne hromatografije u koloni pod visokim pritiskom (HPLC - High Perfomace Liquid Chromatography)

Modern analytical techniques in the assessment of the authenticity of Serbian honey

Food authenticity in a broader sense means fulfilling chemical and physical criteria prescribed by the proposed legislation. In the case of honey authenticity, two aspects are of major concern: the manufacturing process and the labelling of final products in terms of their geographical and botanical origin. A reliable assessment of honey authenticity has been a long-term preoccupation of chemists-analysts and it usually involves the use of several criteria and chemical markers, as well as a combination of analytical and statistical (chemometric) methods. This paper provides an overview of different criteria and modern methods for the assessment of honey authenticity in the case of a statistically significant number of authentic honey samples of several botanical types from various regions of Serbia

Thin-layer chromatography on polyacrylonitrile. IV. Investigation of the separation mechanisms for tris-(alkylxanthato)cobalt(III) complexes

The chromatographic behaviour of six tris(alkylxanthato)cobalt(III) complexes on polyacrylonitrile sorbent thin layers was investigated using four non-aqueous and two aqueous solvent systems. It was assumed that their separation under normal-phase conditions was achieved by the mechanism of hydrogen-bond formation between highly electronegative sorbate oxygen and/or sulphur atoms and sorbent methyne group hydrogens. In contrast, it was assumed that under reversed-phase conditions the separation was based on non-specific hydrophobic interactions. Finally, the linear dependence between the number of carbon atoms in the ligands and the corresponding RM values of the investigated complexes of a homologous series was confirmed. © 1992

Razlikovanje komercijalnih uzoraka vina korišćenjem fluorescentne spektroskopije i multivarijacione analize

Steady state fluorescence spectroscopy in combination with Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) for spectral analysis has been applied to differentiate commercial samples of wines available on the market. We have chosen the wine trade marks from the two Serbian producers that contain only one wine type, since such approach is a starting step for further analyses of the more complex samples containing different wine types. We also studied changes of the emission spectra of these samples during seven days after opening of the wine bottle. The emission spectra were recorded in the wavelength range 275 - 500 nm, after excitation in the range 255 - 300 nm. The spectra of the wine samples obtained from the same producer are very similar, i.e. contain the same components in the similar ratios. The changes of spectral components at 315 nm and 430 nm were the basis for differentiation of the wine samples from the two producers, as well as for estimation of the wine stability in time after the bottle opening. The results indicate that this may be a useful approach in fingerprinting wines from various producers, as well as in screening the stability of wine.Fluorescentna spektroskopija u kombinaciji sa metodom Multivarijaciona Rezolucija Krivih - Naizmenični Najmanji Kvadrati (Multivariate Curve Resolution - Alternating Least Squares, MCR-ALS), je primenjena za razlikovanje komercijalnih uzoraka vina dostupnih na tržištu. Odabrali smo trgovačke marke vina od dva srpska proizvođača koje sadrže samo jednu vrstu vina, jer je ovakav pristup početni korak za kasnije analize složenijih uzoraka koji sadrže različite vrste vina. Takođe smo proučavali promene emisionih spektara ovih uzoraka u toku sedam dana posle otvaranja boce. Emisioni spektri su mereni u opsegu talasnih dužina 275 - 500 nm, posle pobuđivanja u opsegu 255 - 300 nm. Spektri uzoraka vina od istog proizvođača su veoma slični, to jest sadrže iste komponente u sličnom međusobnom odnosu. Promene komponenata spektara na 315 nm i 430 nm bile su osnova za razlikovanje uzoraka vina od dva proizvođača, kao i za procenu stabilnosti vina u vremenu posle otvaranja boce. Rezultati ukazuju da ovo može biti koristan pristup u razlikovanju vina od različitih proizvođača, kao i u praćenju stabilnosti sastava vina

Supplementary data for the article: Šegan, S.; Opsenica, I.; Zlatović, M.; Milojković-Opsenica, D.; Šolaja, B. Quantitative Structure Retention/Activity Relationships of Biologically Relevant 4-Amino-7-Chloroquinoline Based Compounds. Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences 2016, 1012–1013, 144–152. https://doi.org/10.1016/j.jchromb.2016.01.033

Supplementary material for: [https://doi.org/10.1016/j.jchromb.2016.01.033]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2059

Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites

The separation and chromatographic behaviour of five ACE (angiotensin converting enzyme) inhibitors and their four active metabolites were investigated by normal-phase thin-layer chromatography on silica using several mono- and binary non-aqueous solvent systems. The linear relationship between the RM values and the composition of employed mobile phase was obtained. The hydrophobicity parameters RM0 and C0 were determined from the regression data of the plots, analogous to reversed-phase chromatography. The chromatographically obtained hydrophobicity parameters were correlated with the calculated log P values. The current results were correlated with the lipophilicity of the studied ACE inhibitors and their metabolites, previously estimated by reversed-phase chromatography

Sugar profile as a tool for the assesment of influence of tetraoxanes on germination and starting growth phase of maize seeds

U ovom radu ispitan je uticaj serije 1,2,4,5-tetraoksana na metabolizam klijanja u ranim fazama rasta i razvića kukuruza. Primenom visoko-efikasne jonske hromatografije sa amperometrijskom detekcijom analiziran je sadržaj šećera u korenu i izdanku kukuruza, čija semena su bila potopljena u rastvore tetraoksana koncentracija 1×10-6 M, 1×10-9 M i 1×10-12 M. Sadržaj analiziranih šećera ukazuje na različit odgovor biljke na prisustvo svakog od ispitivanih tetraoksana. Uočeno je da dolazi do povećanja sadržaja gotovo svih šećera u tretiranim uzorcima, u odnosu na kontrolne, a naročito šećera koji povećavaju toleranciju biljke na abiotski stres, kao što su glukoza, saharoza, rafinoza, trehaloza i arabinoza. Za svaki od ispitivanih tetraoksana mogu se definisati optimalne koncentracije koje bi imale najveći uticaj na pravilan rast i razviće kukuruza.The influence of the series of 1,2,4,5-tetraoxanes on metabolism of germination and starting growth phase of maize seeds was examined. Sugar content in shoot and root of seeds immersed in tetraoxane solution of different concentration, 1×10-6 M, 1×10-9 M i 1×10-12 M, were determined by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection. The content of all analysed sugars revealed different responce of the plant to the presence of each of the tested tetraoxanes. It has been observed a higher content of almost all sugars in the treated samples, compared to control, and especially sugars which increase the tolerance of the plant to abiotic stress, such as glucose, sucrose, raffinose, trehalose and arabinose. The optimal concentration of each tested compound that would have the greatest effect on proper growth and development of maize, could be defined

Thin-layer chromatography on polyacrylonitrile. V. Consideration of separation mechanisms of some aliphatic and aromatic amines

The chromatographic behaviour of ten aliphatic and aromatic amines on thin layers of polyacrylonitrile sorbent was investigated using seven aqueous solvent systems. It was established that an increase in the hydrophobic part of the amines results in their increased retention on this sorbent. A positive linear depencence between the number of carbon atoms in the n-alkyl groups of primary aliphatic amines and the corresponding RM values was also established. The separation of the investigated amines was assumed to be based on non-specific hydrophobic interactions between their non-polar parts and the hydrocarbon chains of the sorbent. © 1992

Supplementary data for the article: Šegan, S.; Opsenica, I.; Zlatović, M.; Milojković-Opsenica, D.; Šolaja, B. Quantitative Structure Retention/Activity Relationships of Biologically Relevant 4-Amino-7-Chloroquinoline Based Compounds. Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences 2016, 1012–1013, 144–152. https://doi.org/10.1016/j.jchromb.2016.01.033

Supplementary material for: [https://doi.org/10.1016/j.jchromb.2016.01.033]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2059

Kvantitativna analiza arbutina i hidrokinona u listovima obične planike (Arbutus unedo L., Ericaceae) plinskokromatografskom metodom uz detekciju masenim spektrometrom

The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R2>0.9987) in the tested concentration range (0.5-200 μg mL-1), as well as good precision (RSD0,9987) u ispitivanom koncentracijskom rasponu (0,5-200 μg mL-1), kao i dobru preciznost (RSD<5 %), analitički povrat (96,2-98,0 %) i osjetljivost (granica detekcije=0,009 μg mL-1 za arbutin i 0,004 μg mL-1 za hidrokinon). Rezultati dobiveni validiranom GC-MS metodom u dobroj su suglasnosti s rezultatima dobivenim metodom tekućinske kromatografije visoke učinkovitosti (HPLC). Predložena metoda je primijenjena za određivanje sadržaja arbutina i hidrokinona u metanolnom ekstraktu lišća. Sadržaj arbutina određen u lišću obične planike prikupljenom na otoku Koločepu (6,82 mg g-1 suhe mase) bio je veći u usporedbi sa sadržajem arbutina u lišću prikupljenom na otoku Malom Lošinju (2,75 mg g-1 suhe mase). Hidrokinon nije detektiran ni u jednom uzorku. Analitičke značajke predložene GC-MS metode pokazale su da se arbutin i hidrokinon mogu alternativno određivati plinskom kromatografijom. S obzirom na široki koncentracijski raspon, metoda je pogodna za analizu arbutina i hidrokinona, ne samo u lišću obične planike, nego također i u lišću biljaka drugih porodica (Rosaceae, Lamiaceae, itd.)