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PL
W pracy zaprezentowanej w artykule oznaczono zawartość kofeiny w naparach wybranych kaw mielonych, rozpuszczalnych i ziarnistych metodą wysokosprawnej chromatografii cieczowej (HPLC).
EN
The study determined the caffeine content in brews of selected ground, soluble and coffee beans using high–performance liquid chromatography (HPLC).
EN
In the present study the authors assessed chemical stability of four light-cured orthodontic adhesives: Contec LC, Transbond XT, Transbond Plus, Resilience, with respect to temperature of the external environment. Polymerized samples of orthodontic adhesives were treated with pH 7 phosphate-citrate buffer solutions based on HPLC-grade water at 20, 36 and 50°C. After 1 hour, 24 hours and 7 days of sample incubation, the obtained eluates were analyzed using the high performance liquid chromatography method (HPLC) which confirmed the presence of triethylene glycol dimethacrylate (TEGDMA) monomer in solutions obtained after incubation of Contec LC, Resilience and Transbond XT samples. The presence of ethylene glycol dimethacrylate (EGDMA) monomer was also detected in eluates obtained from the Resilience adhesive. The eluates obtained after storage of Transbond Plus adhesive system were free of the sought substances. TEGDMA monomer concentrations were highest in the eluates obtained after 1 hour of incubation, the lowest after 7 days of storage of orthodontic adhesive samples, regardless of the temperature of the phosphate-citrate buffer. In addition, there were statistically significant differences in concentrations of monomers depending on the tested adhesive system. The rate of degradation of orthodontic adhesives based on a polymer network may also be adversely affected by an increase in ambient temperature.
PL
Oceniano stabilność chemiczną czterech światłoutwardzalnych klejów ortodontycznych: Contec LC, Transbond XT, Transbond Plus oraz Resilience w warunkach zmiennych wartości temperatury środowiska zewnętrznego. Spolimeryzowane próbki klejów poddawano działaniu roztworów buforu fosforanowo-cytrynianowego na bazie wody o czystości HPLC o pH 7 i temperaturze 20, 36 i 50 °C. Po upływie 1 h, 24 h i 7 dni inkubacji próbek uzyskane eluaty analizowano metodą chromatografii cieczowej wysokociśnieniowej HPLC, która potwierdziła obecność monomeru dimetakrylanu glikolu trietylenowego (TEGDMA) w roztworach otrzymanych po inkubacji próbek materiałów Contec LC, Resilience i Transbond XT. W eluatach uzyskanych z kleju Resilience wykryto ponadto obecność monomeru dimetakrylanu glikolu etylenowego (EGDMA). Eluaty otrzymane po inkubacji systemu adhezyjnego Transbond Plus były wolne od poszukiwanych substancji. Największe stężenia monomeru TEGDMA były w eluatach uzyskanych po 1 h inkubacji, a najmniejsze po 7 dniach przechowywania próbek klejów ortodontycznych, niezależnie od temperatury buforu fosforanowo-cytrynianowego. Wykazano też istnienie istotnych statystycznie różnic stężeń oznaczonych monomerów w zależności od badanego systemu adhezyjnego. Zaobserwowano, że wzrost temperatury otoczenia może wywierać niekorzystny wpływ także na tempo degradacji klejów ortodontycznych opartych na matrycy polimerowej.
EN
Chemical stability of composite adhesive systems is crucial for the safety of their use.The study assessed chemical stability of four light-cured orthodontic adhesives: Contec LC, Transbond XT, Transbond Plus, Resilience, depending on pH value of the external environment. Samples of polymerized or­thodontic adhesives were treated with (high-performance liquid chromatography) HPLC-grade water solutions of phosphate-citrate buffer with pH values respectively: 4, 5,6 and 7 at 36 °C. The eluates obtained after 1 hour, 24 hours and 7 days of sample incubation were analyzed for the presence of camphorquinone (CQ), bisphenol A (BPA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), bisphenol A diglycidyl methacrylate (Bis-GMA), ethylene glycol dimethacrylate (­EGDMA), 2,2-dimethoxy-2-phenylacetophenon (DMPA) usingultra-high performance liquid chromatography (UHPLC). Out of the seven searchable substances, TEGDMA was present in eluates obtained from Contec LC, Resilience and Transbond XT materials and EGDMA in eluates obtained from Resilience adhesive. The eluates obtained from the Transbond Plus adhesive system were virtually free of the sought substances. The highest concentrations of TEGDMA in solutions were recorded after 1 hour of incubation regardless ofthe type of material. In the case of Contec LC material, an increase in TEGDMA concentrations was observed along with an increase in the solutions’ pH, butonly for the elution period of 1 hour and 7 days, the effect of the solvent’s pH was statistically significant (p ≤ 0.001). In the case of Resilience and Transbond XT, no significant differences in TEGDMA concentrations were observed with respect to pH of the external environment. In the conditions of the conducted study, a lack of chemical stability was confirmed for the majority of assessed orthodontic adhesive systems based on polymers, expressed in emission of component monomers to the external environment. The chemical compound identified in the study was TEGDMA, and for each pH of the solvent, statistically significant differences in its release were found between the materials. However, no explicit relationship was observed between chemical in stability of the studied materials and pH of the external environment within the assumed range of assessment.
PL
Stabilność chemiczna kompozytowych systemów adhezyjnych jest kluczowa z punktu widzenia bezpieczeństwa ich stosowania. W badaniu oceniano stabilność chemiczną czterech światłoutwardzalnych klejów ortodontycznych: Contec LC, Transbond XT, TransbondPlus, Resilience, w zależności od wartości pH środowiska zewnętrznego. Próbki spolimeryzowanych klejów ortodontycznych poddano działaniu roztworów buforufosforanowo-cytrynianowego na bazie wody o czystości HPLC, o wartości pH: 4, 5,6 oraz 7 i temperaturze 36 °C. Eluaty uzyskane po 1 h, 24 h i 7 dniach inkubacji próbek analizowano metodą chromatografii cieczowej wysokociśnieniowej (HPLC) pod względem obecności kamforochinonu (CQ), bisfenolu A (BPA), dimetakrylanu glikolu trietylenowego (­TEGDMA), dimetakrylanu uretanu (UDMA), bisfenolu A metakrylanu diglicydylu (Bis-GMA), dimetakrylanu glikoluetylenowego (EGDMA), 2,2-dimetoksy-2-fenyloacetofenonu (DMPA). Z siedmiu związków chemicznych identyfikowanych w roztworach potwierdzono obecność TEGDMA w eluatach uzyskanych z materiałów Contec LC, Resilience i Transbond XT oraz obecność EGDMA w eluatach z kleju Resilience. Eluaty otrzymane z systemu adhezyjnego TransbondPlus praktycznie biorąc nie zawierały poszukiwanych substancji. Największe stężenia TEGDMA w roztworach stwierdzono po 1 h inkubacji próbek ortodontycznych systemów łączących, niezależnie od rodzaju materiału. W odniesieniu do kleju Contec LC obserwowano wzrost stężenia TEGDMA wraz zwartością pH roztworów, ale wpływ pH rozpuszczalnika był istotny statystycznie (p ≤ 0,001) tylko w wypadku czasu wymywania 1 h i 7 dni. W roztworach po inkubacji materiałów Resilience i Transbond XT nie stwierdzono istotnych różnic stężeń TEGDMA w zależności od pH środowiska zewnętrznego. W warunkach przeprowadzonego badania potwierdzono brak stabilności chemicznej większości ocenianych, polimerowych, ortodontycznych systemów adhezyjnych wyrażający się emisją tworzących je monomerów do środowiska zewnętrznego. W odniesieniu do każdej wartości pH rozpuszczalnika wykazano istotne statystycznie różnice w uwalnianiu ­TEGDMA pomiędzy badanymi materiałami. Jednocześnie w przyjętym zakresie oceny nie zaobserwowano jednoznacznej zależności stabilności chemicznej badanych materiałów od pH środowiska zewnętrznego.
PL
Hemoglobinopatie to różnorodna grupa chorób należąca do niedokrwistości hemolitycznych uwarunkowanych genetycznie. Występują one przede wszystkim w rejonach tropikalnych i subtropikalnych. Podłożem choroby mogą być zaburzenia syntezy (hemoglobinopatie ilościowe: talasemie) i/lub struktury hemoglobiny (hemoglobinopatie jakościowe: warianty hemoglobin) spowodowane mutacjami w genach kodujących to białko. W Zakładzie Immunologii Hematologicznej i Transfuzjologicznej diagnostyka hemoglobinopatii opiera się na badaniach biochemicznych (oznaczanie HbA2, HbF, Hb patologicznych metodą HPLC) oraz molekularnych (gap-PCR, MLPA, sekwencjonowanie HBB, HBA2 i HBA1). W wyniku postępującej migracji ludności choroby te są coraz częściej wykrywane w Polsce. Dzięki udoskonalonej diagnostyce wykrywane są przypadki o bardzo zróżnicowanym podłożu.
EN
Haemoglobinopathies are a diverse group of hereditary hemolytic anemias caused by mutations that affect the synthesis (quantitative haemoglobinopathies: thalassemias) and/or the structure (qualitative haemoglobinopathies: structural hemoglobin variants) of haemoglobin. In the Department of Immunohaematology and Immunology of Transfusion Medicine, the diagnostics of haemoglobinopathy is based on biochemical tests (determination on HbA2, HbF and abnormal haemoglobin by the HPLC method) and molecular tests (gap-PCR, MLPA, the sequencing of HBB, HBA2 and HBA1). As a result of the progressive migration of the population, various haemoglobinopathies are also detected in Poland.
5
EN
Cotton fabrics were treated with cosmetic substances based on α-tocopherol and cyclodextrine. Isolation of α-tocopherol from cotton cosmetotextiles was performed using three different techniques: stirring, Soxhlet and microwave extraction. High performance liquid chromatography (HPLC) was optimised and applied for the quantification of α-tocopherols in the isolates. The results revealed that all techniques are applicable for the isolation of α-tocopherol from cotton cosmetotextiles. The HPLC method proved to be the most convenient for the quantification of α-tocopherol from cotton fabrics.
PL
W pracy obrabiano tkaniny bawełniane substancjami kosmetycznymi na bazie tokoferolu i cyklodekstryny. Izolację tokoferolu z kosmetotekstyliów bawełnianych przeprowadzono stosując trzy różne techniki: mieszanie, Soxhleta i ekstrakcję mikrofalową. Do oznaczenia ilościowego tokoferoli w izolatach zastosowano wysokosprawną chromatografię cieczową (HPLC). Wyniki wykazały, że wszystkie techniki mają zastosowanie do izolacji α-tokoferolu z kosmetotekstyliów bawełnianych. Metoda HPLC okazała się najbardziej dogodna do ilościowego oznaczenia α-tokoferolu z tkanin bawełnianych.
EN
Method for the analysis of intracellular adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) in Mycobacterium smegmatis that involves rapid extraction procedure based on sonication of cells in perchloric acid, as well as separation of nucleotides by ion-pair reversed-phase high-performance liquid chromatography and ultraviolet (UV) detection at 254 nm, is developed. The analytes were separated with mobile phase consisted of acetonitrile and 50 mM monobasic potassium phosphate (pH 4.6) with 25 mM tetrabutylammonium hydrogensulfate in a ratio of 0.5:99.5% within 30 min. The calibration curves were linear in the range of 20–1000 pmol of ATP and 10–1000 pmol of ADP and AMP with correlation coefficient (r2) of ≥0.9998. The proposed method is applicable for mycobacterium cultures taken over a wide range of optical density and physiological states. Concentrations of ATP, ADP, and AMP in mycobacterial extracts varied from 2.61 ± 0.27 to 9.60 ± 0.19 nmol/mg dry weight, from 1.75 ± 0.12 to 5.86 ± 0.09 nmol/mg dry weight, and from 0.55 ± 0.08 to 4.40 ± 0.07 nmol/mg dry weight, respectively, depending on the physiological state.
EN
Irinotecan (IRT) is an antineoplastic agent widely used in the treatment of various cancers primarily in colorectal cancer. A new, simple and sensitive high-performance liquid chromatography (HPLC) method coupled with fluorescence detector was developed and validated to quantify IRT and its active metabolite SN38 in the plasma of non-obese diabetic/severe combined immune-deficient mice (NOD/SCID) mice bearing colon tumor. The plasma samples were extracted by precipitation method using acetonitrile with 0.1% formic acid. The chromatographic separation was achieved using mobile phase consisted of water and acetonitrile (57:43 v/v) pH 3 at the flow rate of 0.8 mL/min in C18 column (internal diameter, 250 × 4.6 mm; pore size, 5 μm). The method was validated according to the bioanalytical guidelines defined by Food and Drug Administration (FDA) and European Medicine Agency (EMA). A regression (R2) value of 0.999 and 0.997 for IRT and SN38 suggested the good linearity in the range of 0.1–10 μg/mL and 5–500 ng/mL, respectively. The calculated lower limit of quantification (LLOQ) and limit of detection (LOD) for IRT were 0.1 and 0.065 μg/mL, respectively. However, for SN38, LLOQ and LOD were 5 and 2 ng/mL, respectively. The intra-day and inter-day variations (coefficient of variance; % CV) observed during the validation were found to be within the set limit of 15%. Both accuracy and percentage recovery analyzed and calculated from the quality control samples were in the between the defined range of 85–115%. Plasma samples were found to be stable when stored at room temperature for 2 h, after 2 freeze–thaw cycles and at −80 °C for 2 months. The developed method was successfully applied to study the plasma elimination profile of IRT in NOD/SCID mice with tumor. The results from plasma concentration time profile and pharmacokinetic parameter analyzed suggested the rapid elimination of IRT and SN38 from the plasma of NOD/SCID mice.
EN
A new reversed-phase high-performance liquid chromatographic method with ultraviolet detection (RP-HPLC-UV) for simultaneous determination of phenytoin impurities, benzophenone and benzil, was developed and validated according to the International Council for Harmonization (ICH) guidelines. Chromatographic separation was performed on a C8 column using acetonitrile–1% acetic acid (60:40, v/v). The correlation coefficients of the calibration lines were greater than 0.999 with 95% confident interval of y-intercept over the origin. The analytical method showed good precision, intra-day precision ≤1.00 and inter-day precision ≤1.53. The standard solution of each compound exhibited good stability 99.18–99.70%, after storage at room temperature for 24 h. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0015 and 0.005 μg/mL, respectively. The resolution of the impurities was 2.935 ± 0.009. The proposed analytical method was successfully applied to determine the amount of benzophenone and benzil in marketed products. The amount of benzophenone was found at 3.09–5.91 × 10−3%, while benzil was not detected in the samples.
EN
A simple, efficient, and stable high-performance liquid chromatography (HPLC) separation method for a combination of rifampicin (RIF), its major metabolite 25-O-desacetyl rifampicin (25ODESRIF), and neostigmine (NEO) was developed and validated. The drugs individually, and in combination, were analyzed using a Waters Alliance 2695 HPLC coupled with 2996 photodiode array detector (PDA). Successful separation of combined drugs was achieved by gradient elution on a reverse-phase C-18 Phenomenex Luna column, using a mobile phase consisting of water and methanol at detection wavelength of 254 nm. The HPLC retention times were consistent at ±7.70 min, ±8.25 min, and ±10.70 min for RIF, 25ODESRIF, and NEO, respectively. The regression data for the calibration plots exhibited linear relationship (R2 = 0.995) in the range of 0–200 μM for both RIF and 25ODESRIF, and the lower limit of detection (LLOD) and lower limit of quantification (LLOQ) were calculated at 5.86 μM and 17.75 μM for RIF and 7.78 μM and 23.57 μM for 25ODESRIF, respectively. The method was evaluated using in vitro human liver microsomes (HLMs) assays, and linearity was established for the 15, 30, 45, and 60 min incubations (R2 = 0.99). The formation of 25ODESRIF was characterized by hyperbolic kinetics (Km 48.23 μM, Vmax 1.233 pmol/min/mg protein, and CLint 0.026 μl/min/mg protein). The method was applied in HLM assays to understand the herb–drug interaction (HDI) potential of Althaea officinalis, a popular African herb consumed by tuberculosis (TB) patients, with RIF. None of the extracts of A. officinalis inhibited the esterase-mediated metabolism pathway of RIF, compared to the positive control nelfinavir (IC50 = 9.59 μM). The method provides a tool for quantifying RIF and 25ODESRIF in in vitro drug metabolism assays as well as investigating herb– and drug–drug interactions (DDIs).
10
Content available Metody oznaczania barwników spożywczych
EN
Food dyes are chemical substances that were developed to enhance the appearance of food by giving it artificial color. People have added colorings to food for centuries, but the first artificial food colorings were created in 1856 from coal tar. Over the years, hundreds of artificial food dyes have been developed, but a majority of them have since been found to be toxic. There is only a handful of artificial dyes that are still used in food. Food manufacturers often prefer artificial food dyes over natural food colorings, such as beta carotene and beet extract, because they produce a more vibrant color [1]. However, there is quite a bit of controversy regarding the safety of artificial food dyes. All of the artificial dyes that are currently used in food have gone through testing for toxicity in animal studies. Regulatory agencies, like the US Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), have concluded that the dyes do not pose significant health risks. Not everyone agrees with that conclusion. Interestingly, some food dyes are deemed safe in one country, but banned from human consumption in another, making it extremely confusing to assess their safety [2]. Undesirable effects of azo dyes used for coloring food products led to the development of very sensitive and selective analytical methods successfully used for their determination in various food matrices. Many different methods have been employed for the determination of synthetic dyes in food and beverages including thin layer chromatography and capillary electrophoresis [3]. However, these methods can be time consuming and may not be applicable for the simultaneous analysis of many dyes. Conventional HPLC methods have been employed for the analysis of synthetic colorants and while useful, these methods require long analysis times and large amounts of expensive solvents [4, 5]. Preparation of the test sample involves the use of various techniques such as membrane filtration due to the complexity of food products. Therefore, the development of simple, selective extraction methods together with the combination of chromatographic and spectrophotometric techniques are of great importance [6]. One of the most difficult stages of the analysis is the appropriate selection of the method for the determination of food colors. In the case of spectrophotometric methods, the main advantage is the low cost of the determination, however, the lack of specificity of the absorption spectrum usually makes it difficult to apply this method in the case of a mixture of different absorbing dyes due to the overlap of the spectra. The CE (Capillary Electrophoresis) analysis is faster and more economical compared to conventional electrophoresis and chromatography. The production of cheap capillaries and the development of on-line detection systems contributed to the development of modern capillary electrophoresis. Capillary electrophoresis has a number of types of separation. Ultimately, it is impossible to determine the one particular appropriate specific method for the determination of food dyes due to their diverse structure and chemical composition [4, 7].
PL
W ostatnich latach obserwujemy wzrost wykorzystania detektora wyładowań koronowych (CAD) sprzężonego z chromatografem cieczowym w analizach produktów spożywczych, farmaceutycznych, kosmetycznych i innych. Technika ta charakteryzuje się wysoką czułością i szerokim zakresem dynamicznym, a odpowiedź substancji badanej jest niezależna od jej struktury chemicznej. W pracy opisano zasadę działania CAD oraz przedstawiono wybrane zastosowania w analizach związków niezawierających chromoforów i w analizach mających na celu zredukowanie liczby wzorców.
EN
In recent years we have seen an increase in the use of a corona charged aerosol detector (CAD) coupled with liquid chromatography in the analyses of food, pharmaceuticals, cosmetics and others. This technique is characterized by high sensitivity and a wide dynamic range, while the analyte response does not depend on its chemical structure. In the paper we explain the operating principle of CAD and provide its exemplary applications in the analyses of compounds without chromophores and the analyses aimed at reducing the number of used standards.
EN
The growing consumers’ awareness in the nutrition area, the desire to look for alternatives to white sugar and the trend to live healthily have led to an increase in the supply of sugar syrups on the organic market. Insufficient number of studies on the health attributes of these syrups does not allow to state clearly that they are a good substitute for saccharose. The aim of the work was to identify and determine the content of biologically active compounds and sugars content of natural sugar syrups from organic production. Purchased products have been examined to indicate the content of individual sugars and polyphenol compounds. The type of sugar syrup had an impact on the nutritional value, the content of dry matter, sugar and the content of bioactive compounds such as polyphenols. The obtained results showed that sugar beet as well as date syrup due to high content of bioactive compounds are nutritionally beneficial.
PL
Rosnąca świadomość żywieniowa konsumentów, chęć poszukiwania alternatyw dla białego cukru oraz trend zdrowego trybu życia spowodowały wzrost podaży roślinnych syropów cukrowych na rynku żywności ekologicznej. Niedostateczna ilość badań nad walorami zdrowotnymi tych syropów nie pozwala jednoznacznie stwierdzić, że stanowią dobry substytut sacharozy. Celem niniejszej pracy była identyfikacja i określenie zawartości związków biologicznie czynnych oraz wartości odżywczej rynkowych syropów słodzących z produkcji ekologicznej. W zakupionych produktach oznaczono zawartości poszczególnych cukrów oraz związków polifenolowych. Rodzaj syropu cukrowego miał wpływ na wartość odżywczą, zawartość suchej masy, cukrów i związków bioaktywnych, takich jak polifenole. Na podstawie uzyskanych wyników stwierdzono, że syropy buraczany i daktylowy z uwagi na wysoką zawartość związków bioaktywnych są korzystne pod względem żywieniowym.
PL
W artykule przedstawiono wybrane metody analizy żywności, rozpoczynając od klasycznego miareczkowania, a kończąc na komputerowej analizie obrazu. Omówiono również metody chromatograficzne wykorzystywane w analizach środków spożywczych, takie jak wysokosprawna chromatografia cieczowa (HPLC) czy połączenie chromatografii gazowej ze spektrometrią mas (GC-MS). Wskazano także możliwości wykorzystania metod termicznych analizy żywności, ze szczególnym uwzględnieniem różnicowej kalorymetrii skaningowej (DSC) .
EN
The article presents selected methods of food analysis, beginning with the classical titration and ending with computer image analysis. The chromatographic methods used in the analysis of foodstuffs, such as high performance liquid chromatography (HPLC) or the combination of gas chromatography with mass spectrometry (GC-MS) were also discussed. The possibilities of using methods thermal methods of food analysis, with particular emphasis on differential scanning calorimetry (DSC) have also been indicated.
PL
Celem pracy było zbadanie czy proces fermentacji (na różnych jego etapach) miodu wpływa na jego właściwości antyoksydacyjne. Ponadto zbadano wpływ różnych dodatków (moszczy owocowych i ziół) na nie. Aby móc przedyskutować mechanizm tych zmian pomiary odniesiono do rodników różnej mocy (hydroksylowych i DPPH), a także do pomiarów amperometrycznych (w układzie przepływowym, HPLC). Wyniki te skorelowane zostały m.in. z całkowitą zawartością polifenoli. Aby przedyskutować korelacje otrzymane różnymi technikami zbadano dodatkowo stężenie etanolu i cukrów w badanych próbkach.
EN
The aim of the paper was to investigate whether the fermentation process (at its various stages) affects honey’s antioxidant properties. The effect of various additives (herbs and fruit musts) on them has been also examined. The measurements were performed with reference to various radicals (DPPH and hydroxyl radicals) as well as to amperometric measurements in a flow system (HPLC). This allows a better understanding of the mechanism of the antioxidant interactions. The obtained results were correlated with the concentration of ethanol and sugars and total polyphenol content in the sample.
PL
W pracy przedstawiono wyniki badań nad możliwością zastosowania rodnika DPPH do oznaczania właściwości antyoksydacyjnych, stosując chromatograficzne rozdzielanie różnych jego form. Pomiary wykonywane były w układzie faz odwróconych HPLC z detekcją UV-DAD. Zbadano CPA związków o właściwościach przeciwutleniających – flawonoidów, jak również całkowity potencjał antyoksydacyjny wybranych naparów z ziół. Wyniki otrzymane za pomocą RP-HPLC-UV skorelowane zostały z wynikami otrzymanymi w pomiarze fotometrycznym.
EN
The paper presents the results of the possibility of using the DPPH radical to determine antioxidant properties using chromatographic separation of its various forms. The measurements were performed in the RP-HPLC with UVDAD detection. The TAP values were tested for antioxidants - flavonoids, as well as the total antioxidant potential of selected herbs. The results obtained with RP-HPLC-UV were correlated with the results obtained using photometric measurement.
EN
A validated high-performance liquid chromatography (HPLC) method has been developed to analyze the (±)-gossypol in the selection of strains of Candida tropicalis culture. Since gossypol was easily degraded and oxidized, the addition of antioxidant NADPH-Na4 and acetone extraction was chosen to prevent gossypol degradation and gradient elution assay was applied to obtain gossypol resolution. Concentrations of gossypol in C. tropicalis ZD-3 culture 20 μg/mL were determined, and concentration–time profiles were observed. Linearity of the gossypol standard curve by HPLC area method was ranged from 0.1 to 20 μg/mL with Y = 26.954 × X − 29.547, R2 = 0.9991, and n = 3, with limit of detection (LOD) of 50 ng/mL and lower limit of quantification (LLOQ) of 500 ng/mL. The recovery rate is dose-dependent and ranged from 85.3% to 103.5%. It is a rapid and reliable HPLC method for gossypol quantization in microorganism culture which could be applied in solid fermentation in the feed industry.
EN
The objective of the current research is to understand the degradation behavior of avanafil under different stress conditions and to develop a stability-indicating high-performance liquid chromatography (HPLC) method for simultaneous determination of degradants observed during degradation. Avanafil tablets were exposed to acid, base, water, oxidative, thermal, and photolytic degradation conditions. In acid, oxidative, thermal, and humidity degradation, significant degradation was observed. All the degradants observed during degradation were separated from known impurities of avanafil by using reverse-phase (RP)-HPLC. Mobile phase A, 0.1% trifluoro acetic acid and triethylamine in water, and mobile phase B, water and acetonitrile in the ratio of 20:80 (v/v), were used at a flow rate of 1.2 mL/min in gradient elution mode. Separation was achieved by using Inertsil ODS 3 column (3 μm, 4.6 mm × 250 mm) at 45 °C. Peak responses were recorded at 245 nm. Method capability for detecting and quantifying the degradants, which can form during stability, was proved by demonstrating the peak purity of avanafil peak in all the stressed samples. Mass balance was established by performing the assay of stressed sample against reference standard. Mass balance was found >97% for all the stress conditions. The developed analytical method was validated as per International Conference on Harmonization (ICH) guidelines. The method was found specific, linear, accurate, precise, rugged, and robust.
EN
A simple and rapid high-performance liquid chromatographic (HPLC) method was established for simultaneous determination of butorphanol tartrate and ondansetron hydrochloride in analgesic mixture samples used for patient-controlled analgesia (PCA). The separation of butorphanol tartrate and ondansetron hydrochloride in PCA solution was carried out on phenomenex C18 column (4.6 mm × 150 mm, 5 μm) using 50 mM sodium acetate (pH 4.0) buffer and acetonitrile (72:28, v/v). Flow rate was 1.0 mL min−1 with a column temperature of 30 °C, and detection wavelength was carried out at 280 nm and 306 nm. Validation of the method was made in terms of specificity, linearity, accuracy, and intra- and inter-day precision, as well as quantification and detection limits. The developed method was successfully used to evaluate the chemical stability of butorphanol tartrate and ondansetron hydrochloride in analgesic mixtures at the usual concentration used for PCA.
EN
Phytoplankton community, diatom to dinoflagellate ratio and pigment composition in surface waters with nutrient data from April 2013 to March 2014 were monitored in the south-eastern (SE) Black Sea using high performance liquid chromatography (HPLC) and microscopic analyses. Microscopic examination revealed a total of 71 species that consist of dinoflagellate (58%), diatoms (25%) and other groups (17%). Microscopy and HPLC-based pigment analyses revealed almost similar results which suggest that the phytoplankton community is mainly composed of diatoms, dinoflagellates and coccolithophores. Fucoxanthin (mean 0.35 ± 019 μg L−1), peridinin (mean 0.18 ± 0.14 μg L−1) and 19-hexanoyloxyfucoxanthin (mean 0.24 ± 0.15 μg L−1) are prominent pigments which showed significant correlation with Diatom-C (r2 = 0.63–0.71, p < 0.05), Dinoflagellate-C (r2 = 0.49–0.80, p < 0.05) and Coccolithophore-C (r2 = 0.72–0.82, p < 0.05), respectively. Mean carbon biomass of diatoms (36.50 ± 9.72 μg L−1) was higher than that of dinoflagellates (33.32 ± 9.05 μg L−1). Significant differences were also observed in nutrient ratio (N:P and Si:N) (One-way ANOVA, p < 0.05). Results illustrate that HPLC-based pigment approach can be used for taxonomic characterisation of phytoplankton groups in the SE Black Sea. Moreover, relatively high dinoflagellate species dominancy and significant correlations between Phyto-C and marker pigments indicate that phytoplankton community composition is shifting towards much smaller groups in SE coasts of the Black Sea.
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