ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Unbekannt

Liquid Chromatography/Tandem Mass Spectrometry Method for Quantitation of Cremophor EL and Its Applications (2013)

V. Vijaya Bhaskar and Anil Middha

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-07-29

Beschreibung: A rapid sensitive and selective MRM based method for the determination of Cremophor EL (CrEL) in rat plasma was developed using liquid chromatography/tandem mass spectrometry (LC-MS/MS). CrEL and polypropylene glycol (internal standard) were extracted from rat plasma with acetonitrile and analysed on C18 column (XBridge, 50 × 4.6 mm, 3.5 μm). The most abundant molecular ions corresponding to PEG oligomers at m/z 828, 872, 916 and 960 with daughter ion at m/z 89 were selected for multiple reaction monitoring (MRM) in electrospray mode of ionisation. Plasma concentrations of CrEL were quantified after administration through oral and intravenous routes in male sprague dawley rats at a dose of 0.26 g/kg. The standard curve was linear (0.9972) over the concentration range of 1.00 to 200 μg/mL. The lower limit of quantitation for CrEL was 1.00 μg/mL using 50 μL plasma. The coefficient of variation and relative error for inter and intra assay at three QC levels were 0.69 to 9.21 and −7.60 to 4.74 respectively. A novel proposal was conveyed to the scientific community, where formulation excipient can be analysed as qualifier in the analysis of NCEs to address the spiky plasma concentration profiles.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

2

Unbekannt

Chemical Constituents of Essential Oil from Lippia sidoides Cham. (Verbenaceae) Leaves Cultivated in Hidrolândia, Goiás, Brazil (2013)

Sandra Ribeiro de Morais, Thiago Levi Silva Oliveira, Maria Teresa Freitas Bara, Edemilson Cardoso da Conceição, Maria Helena Rezende, Pedro Henrique Ferri, and José Realino de Paula

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: Several studies involving the family Verbenaceae, occurring in the Brazilian Cerrado, have emphasized the popular use of many aromatic species. We highlight the use of Lippia sidoides Cham., known as “alecrim pimenta,” native to northeastern Brazil and northern Minas Gerais. Leaves of this species were collected in antropized Brazilian Cerrado area, in Hidrolândia, Goiás, and their essential oils were extracted by hydrodistillation in a Clevenger-type apparatus and thereafter analyzed GC/MS. Among the compounds identified in this study were the most abundant oxygenated monoterpenes, followed by sesquiterpenes hydrocarbons. The oxygenated monoterpene 1,8-cineole was the major constituent followed by isoborneol and bornyl acetate. The chemical composition of essential oil described in this paper differs from that described in the literature for L. sidoides found in its native environment, where the major constituents are thymol and carvacrol.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

3

Unbekannt

Preliminary Assessment of the Chemical Stability of Dried Extracts from Guazuma ulmifolia Lam. (Sterculiaceae) (2013)

Gisely C. Lopes, Renata Longhini, Paulo Victor P. dos Santos, Adriano A. S. Araújo, Marcos Luciano Bruschi, and João Carlos P. de Mello

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: We report the results of a preliminary estimation of the stability of the dried extract from bark of Guazuma ulmifolia Lam. (“Mutamba”), with and without added colloidal silicon dioxide (CSD). The physical and chemical properties and the compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature (45±2∘C) and humidity (75±5%). Thermogravimetry (TG) was supplemented using selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely, procyanidin B2 (PB2) and epicatechin (EP). The results showed that PB2 is an appropriate compound to be used as a chemical marker in the quality control of dried extracts of G. ulmifolia. The stress study showed that there was no significant difference between the two formulations. However, considering the TG data and the high temperatures involved, the results suggest that CSD increases the stability of the dried extract of G. ulmifolia.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

4

Unbekannt

Development of a Novel Biosensor Using Cationic Antimicrobial Peptide and Nickel Phthalocyanine Ultrathin Films for Electrochemical Detection of Dopamine (2013)

Maysa F. Zampa, Inês Maria de S. Araújo, José Ribeiro dos Santos Júnior, Valtencir Zucolotto, José Roberto de S. A. Leite, and Carla Eiras

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: The antimicrobial peptide dermaseptin 01 (DS 01), from the skin secretion of Phyllomedusa hypochondrialis frogs, was immobilized in nanostructured layered films in conjunction with nickel tetrasulfonated phthalocyanines (NiTsPc), widely used in electronic devices, using layer-by-layer technique. The films were used as a biosensor to detect the presence of dopamine (DA), a neurotransmitter associated with diseases such as Alzheimer's and Parkinson's, with detection limits in the order of 10−6 mol L−1. The use of DS 01 in LbL film generated selectivity in the detection of DA despite the presence of ascorbic acid found in biological fluids. This work is the first to report that the antimicrobial peptide and NiTsPc LbL film exhibits electroanalytical activity to DA oxidation. The selectivity in the detection of DA is a fundamental aspect for the development of electrochemical sensors with potential applications in the biomedical and pharmaceutical industries.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

5

Unbekannt

Apolar Compounds in Seaweeds from Fernando de Noronha Archipelago (Northeastern Coast of Brazil) (2013)

Leandro De Santis Ferreira, Izabel Cristina Casanova Turatti, Norberto Peporine Lopes, Thais Guaratini, Pio Colepicolo, Eurico Cabral Oliveira Filho, and Ricardo Clapis Garla

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: Hyphenated techniques of gas chromatography coupled to mass spectrometer were used to determine fatty acids in eleven species of seaweeds from Fernando de Noronha archipelago. The main compounds detected in all studied species were the alcohol phytol and the fatty acids 14 : 0; 15 : 0; 16 : 0; 18 : 0; 18 : 1 n9; 18 : 2 Δ9,12; 20 : 4; 20 : 5. These fatty acids are commonly found in seaweeds present in warm regions. Thus, we found no specificity in the presence of a particular set of fatty acids and the studied species indicating that they are not useful as taxonomic indicators. However, they could be used in a comparative study with algae found in polluted area because many of the studied seaweeds are widespread and Fernando de Noronha has low human influence.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

6

Unbekannt

Concentration of Inorganic Elements Content in Benthic Seaweeds of Fernando de Noronha Archipelago by Synchrotron Radiation Total Reflection X-Ray Fluorescence Analysis (SRTXRF) (2013)

Leandro De Santis Ferreira, Rosana Peporine Lopes, Mabel Norma Costas Ulbrich, Thais Guaratini, Pio Colepicolo, Norberto Peporine Lopes, Ricardo Clapis Garla, Eurico Cabral Oliveira Filho, Adrian Martin Pohlit, and Orghêda Luiza Araújo Domingues Zucchi

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: SRTXRF was used to determine As, Ba, Br, Ca, Co, Cr, Cs, Cu, Dy, Fe, K, Mn, Mo, Ni, Pb, Rb, Sr, Ti, V, and Zn in eleven seaweed species commonly found in Fernando de Noronha: Caulerpa verticillata (J. Agardh) (Chlorophyta), Asparagopsis taxiformis (Delile), Dictyurus occidentalis (J. Agardh), Galaxaura rugosa (J. Ellis & Solander) J. V. Lamouroux, G. obtusata (J. Ellis & Solander) J. V. Lamouroux, G. marginata (J. Ellis & Solander) J. V. Lamouroux (Rhodophyta), Dictyota cervicornis (Kützing), Dictyopteris justii (J. V. Lamouroux), Dictyopteris plagiogramma (Montagne) Vickers, Padina gymnospora (Kützing) Sonder, and a Sargassum sp. (Phaeophyta). Data obtained were compared to those from the analysis of other parts of the world seaweeds using different analytical techniques and were found to be in general agreement in terms of major and minor elemental components. Results provide baseline information about the absorption and accumulation of these elements by macroalgae in the area.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

7

Unbekannt

Characterisation of Flavonoid Aglycones by Negative Ion Chip-Based Nanospray Tandem Mass Spectrometry (2013)

Paul J. Gates and Norberto P. Lopes

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: Flavonoids are one of the most important classes of natural products having a wide variety of biological activities. There is wide interest in a range of medical and dietary applications, and having a rapid, reliable method for structural elucidation is essential. In this study a range of flavonoid standards are investigated by chip-based negative ion nanospray mass spectrometry. It was found that the different classes of flavonoid studied have a combination of distinct neutral losses from the precursor ion [M-H]− along with characteristic low-mass ions. By looking only for this distinct pattern of product ions, it is possible to determine the class of flavonoid directly. This methodology is tested here by the analysis of a green tea extract, where the expected flavonoids were readily identified, along with quercetin, which is shown to be present at only about 2% of the most intense ion in the spectrum.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

8

Unbekannt

Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone (2013)

V. S. Anusuya Devi and V. Krishna Reddy

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-03-07

Beschreibung: Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) reacts with iron(II) and cobalt(II) to form reddish-brown and yellow-coloured [Fe(II)-HNAHBH] and [Co(II)-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II)-HNAHBH], Beer’s law is obeyed over the concentration range of 0.055–1.373 μg mL−1 with a detection limit of 0.095 μg mL−1 and molar absorptivity ɛ, 5.6 × 104 L mol−1 cm−1. [Co(II)-HNAHBH] complex obeys Beer’s law in 0.118–3.534 μg mL−1 range with a detection limit of 0.04 μg mL−1 and molar absorptivity, ɛ of 2.3 × 104 L mol−1 cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

9

Unbekannt

Determination of Mercury in Ayurvedic Dietary Supplements That Are Not Rasa Shastra Using the Hydra-C Direct Mercury Analyzer (2013)

Amir A. Abdalla and Robert E. Smith

Hindawi

In: International Journal of Analytical Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-04-29

Beschreibung: Mercury has been determined in Ayurvedic dietary supplements (Trifala, Trifala Guggulu, Turmeric, Mahasudarshan, Yograj, Shatawari, Hingwastika, Shatavari, and Shilajit) by inductively coupled plasma-mass spectrometry (ICP-MS) and direct mercury analysis using the Hydra-C direct mercury analyzer (Teledyne Leeman Labs Hudson, NH, USA). Similar results were obtained from the two methods, but the direct mercury analysis method was much faster and safer and required no microwave digestion (unlike ICP-MS). Levels of mercury ranged from 0.002 to 56 μg/g in samples of dietary supplements. Standard reference materials Ephedra 3240 and tomato leaves that were from the National Institute of Standard and Technology (NIST) and dogfish liver (DOLT3) that was from the Canadian Research Council were analyzed using Hydra-C method. Average mercury recoveries were 102% (RSD% 0.0018), 100% (RSD% 0.0009), and 101% (RSD% 0.0729), respectively. Hydra-C method Limit Of Quantitation was 0.5 ng.

Print ISSN: 1687-8760

Digitale ISSN: 1687-8779

Thema: Chemie und Pharmazie

Publiziert von Hindawi

Permalink