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Simultaneous determination of chemical parameters for wine and cider quality control using HPLC-UV/RI system based on reverse-phase separation capabilities
Mitja Martelanc, 2022, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje)

Ključne besede: HPLC-UV-RI, Cider, Wine, Must, Organic aacids, Ethanol, Glucose, Fructose.
Objavljeno v RUNG: 20.02.2023; Ogledov: 917; Prenosov: 0
Gradivo ima več datotek! Več...

3.
Validacija HPLC metode za določanje organskih kislin in sladkorjev v vinu
Kristjan Mesar, 2022, diplomsko delo

Opis: V tem diplomskem delu smo obravnavali proces validacije dveh analiznih metod za določanje kakovosti vina. In sicer smo določali organske kisline kot so vinska kislina, jabolčna kislina, mlečna kislina, citronska kislina, ocetna kislina, in monosaharide glukozo in fruktozo. Analiza teh parametrov je pomembna pri nadzoru procesa pridelave vina kot tudi spremljanju kakovosti vina. V diplomski nalogi smo pregledali glavne metode za določanje kislin in sladkorjev v grozdju in vinu, v samem poskusu pa smo uporabili kromatografsko tehniko na osnovi tekočinske kromatografijo visoke ločljivosti v kombinaciji z detekcijo v ultravijoličnem (UV) za organske kisline in z detekcijo lomnega količnika (RID) za monosaharidne sladkorje. HPLC-UV/RID sistem omogoča enostavno pripravo vzorca na analizo (samo filtracija, mogoče redčitev, če je potrebna), hitro analizo in omogoča zadovoljive meje detekcije za potrebe določevanja omenjenih parametrov. Obe metodi smo opisali z različnimi parametri, kot je ponovljivost, linearnost, izkoristek v štirih različnih matriksih (dve beli vini, eno rdeče in eno jabolčno vino – cider), meja detekcije in meja kvantifikacije. Rezultate kvantifikacije skupnih sladkorjev in organskih kislin v vzorcih vin smo primerjali z rezultati akreditiranega laboratorija kjer je bilo to mogoče in ugotovili, da kvantifikacija z metodo standardnega dodatka omogoča primerljive rezultate z akreditiranim laboratorijem, predvsem za parameter skupni fermentirani sladkorji (glukoza in fruktoza). Vsebnost skupnih kislin določenih kromatografsko je bila nekoliko manjša od parametra skupne titrabilne kisline, kar je najverjetneje posledica manjšega števila posameznih kislin, ki smo jih vključili v ta parameter, pa tudi drugačne metode določanja kislin.
Ključne besede: vino, cider, HPLC, UV, RID, organske kisline, sladkorji, validacija
Objavljeno v RUNG: 02.08.2022; Ogledov: 1799; Prenosov: 59
.pdf Celotno besedilo (1,10 MB)

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Implementation of high performance liquid chromatography coupled to thermal lens spectrometry (HPLC‑TLS) for quantification of pyranoanthocyanins during fermentation of Pinot Noir grapes
Jelena Topič Božič, Lorena Butinar, Natka Ćurko, Karin Kovačević Ganić, Branka Mozetič Vodopivec, Dorota Korte, Mladen Franko, 2020, izvirni znanstveni članek

Opis: In this work high performance liquid chromatography coupled to thermal lens spectrometry (HPLC-TLS) was applied for monitoring of vinylphenolic pyranoanthocyanins formation during the fermentation of Pinot Noir wines. Vinylphenolic pyranoanthocyanins are wine pigments, present in low concentrations, but very important for wine colour stability. Fermentation process was conducted with four different yeast strains, used as starters, either in sequential fermentation of non-Saccharomyces with S. cerevisiae yeast or as single fermentation with S. cerevisiae yeasts in order to test the applicability of developed method for monitoring of selected compounds in real wine fermentation experiments. The developed HPLC-TLS method showed higher sensitivity compared to HPLC coupled to diode array detection (DAD) technique for particular wine colour compounds. Obtained limits of detection (LODs), were 6- and 22-times lower in comparison to HPLC–DAD in gradient and isocratic elution mode, respectively, whereas limits of quantification (LOQs) 5 and 18-times lower. Lower LODs enabled earlier observation of vinylphenolic pyranoanthocyanins formation during fermentation (already at day 7) in the case of HPLC-TLS method in gradient mode, while by using HPLC–DAD in gradient elution mode the formation of vinylphenolic pyranoanthocyanins was noticed only after 12 days of fermentation.
Ključne besede: Thermal lens spectrometry (TLS), High performance liquid chromatography (HPLC), Pyranoanthocyanins, Wine, Yeasts
Objavljeno v RUNG: 18.06.2020; Ogledov: 3282; Prenosov: 0
Gradivo ima več datotek! Več...

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Investigation and determination of metal complexes and organometallic compounds by thermal-lens spectrometry
Leja Goljat, Mikhail A. Proskurnin, Ivan V. Mikheev, Mladen Franko, 2017, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: thermal-lens sprectrometry, thermal-lens microscopy, HPLC, metal complexes, organometallic compounds
Objavljeno v RUNG: 30.08.2017; Ogledov: 4468; Prenosov: 0
Gradivo ima več datotek! Več...

7.
The comparison of anthocyanin and pyranoanthocyanin extraction efficiency in Pinot Noir wine using SPE
Jelena Topic, Dorota Korte, Branka Mozetič Vodopivec, 2017, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: Anthocyanins, wine, Pinot Noir, HPLC, solid-phase extraction
Objavljeno v RUNG: 05.07.2017; Ogledov: 5280; Prenosov: 0
Gradivo ima več datotek! Več...

8.
TLS Spectrometry & Detection in Liquid Chromatography, FIA and Microfluidic Systems
Mladen Franko, predavanje na tuji univerzi

Opis: This presentation provides theoretical backround for thermal lens spectrometry (TLS) and TLS microscopy (TLM) and describes the basic instrumentation for TLS and TLM measurements. Presented applications of TLS and TLM include detection in HPLC (carotenoids, bilirubin, biliverdin), FIA (alergens, Ag, Ag+, phytoplankton and cyanobacterial pigments, organophospate pesticides) and TLM detection in microfluidic systems (Cr(VI), microcystin, NGAL, study of diffusion proceses)
Ključne besede: Spekrometry TLS, TLM, HPLC, FIA, microfluidics, bilirubin, biliverdin, carotenoids, alergens, mikrocystin, pigments, organophosphate pesticides, NGAL, Ag, Cr(VI), diffusion
Objavljeno v RUNG: 16.09.2016; Ogledov: 5209; Prenosov: 3
.pdf Celotno besedilo (35,40 MB)

9.
Application of high-performance liquid chromatography combined with ultra-sensitive thermal lens spectrometric detection for simultaneous biliverdin and bilirubin assessment at trace levels in human serum
Mitja Martelanc, Lovro Žiberna, Sabina Passamonti, Mladen Franko, 2016, izvirni znanstveni članek

Opis: We present the applicability of a new ultra sensitive analytical method for the simultaneous determination of biliverdin and bilirubin in human serum. The method comprises isocratic reversed-phase(RP) C18 high-performance liquid chromatography (HPLC) and thermal lens spectrometric detection (TLS)based on excitation by a krypton laser emission line at 407 nm. This method enables the separation of IX-α biliverdin and IX-α bilirubin in 11 min. with limit of detection (LOD) and limit of quantitation (LOQ) for biliverdin of 1.2 nM and 3 nM, and 1nM and 2.8 nM for bilirubin,respectively.In addition, a step-gradient elution was set up, by changing the mobile phase composition, in order to further enhance the sensitivity for bilirubin determination with LOD and LOQ of 0.5 nM and 1.5 nM, respectively. In parallel, an isocraticHPLC-DAD method was developed for benchmarking against HPLC-TLS methods. The LOD and LOQ forbiliverdin were 6 nM and 18 nM, and 2.5 nM and 8nM for bilirubin,respectively. Additionally, both isocratic methods were applied for measuring biliverdin and free bilirubin in human serum samples (from 2 male and 2 female healthy donors). Combining isocratic HPLC method with TLS detector was crucial for first ever biliverdin determination in serum together with simultaneous free bilirubin determination. We showed for the first time the concentration ratio of free bilirubin versus unbound biliverdin in human serum samples.
Ključne besede: Bilirubin, biliverdin, serum, HPLC, TLS
Objavljeno v RUNG: 29.03.2016; Ogledov: 5546; Prenosov: 0
Gradivo ima več datotek! Več...

10.
Hydroxyl radical scavenging-based method for evaluation of TiO[sub]2 photocatalytic activity
Urška Lavrenčič Štangar, Matija Strlič, Romana Cerc Korošec, Danijela Pucko, 2013, izvirni znanstveni članek

Opis: Hydroxyl radical scavenging-based method for evaluation of TiO[sub]2 photocatalytic activity
Ključne besede: titanium dioxide, photocatalysis, N, N-(5-nitro-1, 3-phenylene)bisglutaramide, radical scavenger, HPLC
Objavljeno v RUNG: 05.01.2016; Ogledov: 5237; Prenosov: 33
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