Displaying publications 441 - 460 of 951 in total

Abstract:
Sort:
  1. Characterization and toxicological evaluation of leachate from closed sanitary landfill
    Emenike CU, Fauziah SH, Agamuthu P
    Waste Manag Res, 2012 Sep;30(9):888-97.
    PMID: 22593235 DOI: 10.1177/0734242X12443585
    Landfilling is a major option in waste management hierarchy in developing nations. It generates leachate, which has the potential of polluting watercourses. This study analysed the physico-chemical components of leachate from a closed sanitary landfill in Malaysia, in relation to evaluating the toxicological impact on fish species namely Pangasius sutchi S., 1878 and Clarias batrachus L., 1758. The leachate samples were taken from Air Hitam Sanitary Landfill (AHSL) and the static method of acute toxicity testing was experimented on both fish species at different leachate concentrations. Each fish had an average of 1.3 ± 0.2 g wet weight and length of 5.0 ± 0.1 cm. Histology of the fishes was examined by analysing the gills of the response (dead) group, using the Harris haemtoxylin and eosin (H&E) method. Finneys' Probit method was utilized as a statistical tool to evaluate the data from the fish test. The physico-chemical analysis of the leachate recorded pH 8.2 ± 0.3, biochemical oxygen demand 3500 ± 125 mg L(-1), COD 10 234 ± 175 mg L(-1), ammonical nitrogen of 880 ± 74 mg L(-1), benzene 0.22 ± 0.1 mg L(-1) and toluene 1.2 ± 0.4 mg L(-1). The 50% lethality concentration (LC(50)) values calculated after 96 h exposure were 3.2% (v/v) and 5.9% (v/v) of raw leachate on P. sutchi and C. batrachus, respectively. The H&E staining showed denaturation of the nucleus and cytoplasm of the gills of the response groups. Leachate from the sanitary landfill was toxic to both fish species. The P. sutchi and C. batrachus may be used as indicator organisms for leachate pollution in water.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry; Mass Spectrometry
  2. Agarose film liquid phase microextraction combined with gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in water
    Sanagi MM, Loh SH, Wan Ibrahim WA, Hasan MN
    J Chromatogr A, 2012 Nov 2;1262:43-8.
    PMID: 23021646 DOI: 10.1016/j.chroma.2012.09.007
    Agarose film liquid phase microextraction (AF-LPME) procedure for the extraction and preconcentration of polycyclic aromatic hydrocarbons (PAHs) in water has been investigated. Agarose film was used for the first time as an interface between donor and acceptor phases in liquid phase microextraction which allowed for selective extraction of the analytes prior to gas chromatography-mass spectrometry. Using 1-octanol as acceptor phase, high enrichment factors in the range of 57-106 for the targeted analytes (fluorene, phenanthrene, fluoranthene and pyrene) were achieved. Under the optimum extraction conditions, the method showed good linearity in the range of 0.1-200 μgL(-1), good correlation coefficients in the range of 0.9963-0.9999, acceptable reproducibility (RSD 6.1-9.2%, n=3), low limits of detection (0.01-0.04 μgL(-1)) and satisfactory relative recoveries (92.9-104.7%). As the AF-LPME device was non-expensive, reuse or recycle of the film was not required, thus eliminating the possibility of analytes carry-over between runs. The AF-LPME technique is environment-friendly and compatible with the green chemistry concept as agarose is biodegradable polysaccharide extracted from seaweed and the procedure requires small volume of organic solvent and generates little waste. The validated method was successfully applied to the analysis of the four analytes in river water samples.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  3. Novel sol-gel hybrid methyltrimethoxysilane-tetraethoxysilane as solid phase extraction sorbent for organophosphorus pesticides
    Wan Ibrahim WA, Veloo KV, Sanagi MM
    J Chromatogr A, 2012 Mar 16;1229:55-62.
    PMID: 22326188 DOI: 10.1016/j.chroma.2012.01.022
    A novel sol-gel hybrid methyltrimethoxysilane-tetraethoxysilane (MTMOS-TEOS) was produced and applied as sorbent for solid phase extraction (SPE). Five selected organophosphorus pesticides (OPPs) were employed as model compounds to evaluate the extraction performance of the synthesized sol-gel organic-inorganic hybrid MTMOS-TEOS. Analysis was performed using gas chromatography-mass spectrometry. Several important SPE parameters were optimized. Under the optimum extraction conditions, the method using the sol-gel organic-inorganic hybrid MTMOS-TEOS as SPE sorbent showed good linearity in the range of 0.001-1 μg L(-1), good repeatability (RSD 2.1-3.1%, n=5), low limits of detection at S/N=3 (0.5-0.9 pg mL(-1)) and limit of quantification (1-3 pg mL(-1), S/N=10). The performance of the MTMOS-TEOS SPE was compared to commercial C18 Supelclean SPE since C18 SPE is widely used for OPPs. The MTMOS-TEOS SPE method LOD was 500-600 × lower than the LOD of commercial C18 SPE. The LOD achieved with the sol-gel organic-inorganic hybrid MTMOS-TEOS SPE sorbent allowed the detection of these OPPs in drinking water well below the level set by European Union (EU) at 0.1 μg L(-1) of each pesticides. The developed MTMOS-TEOS SPE method was successfully applied to real sample analysis of the selected OPPs from several water samples and its application extended to the analysis of several fruits samples. Excellent recoveries and RSDs of the OPPs were obtained from the various water samples (recoveries: 97-111%, RSDs 0.4-2.8%, n=3) and fruit samples (recoveries: 96-111%), RSDs 1-4%, n=5) using the sol-gel organic-inorganic hybrid MTMOS-TEOS SPE sorbent. Recoveries and RSDs of OPPs from river water samples and fruit samples using C18 Supelclean SPE sorbent were 91-97%, RSD 0.9-2.6, n=3 and 86-96%, RSD 3-8%, n=5, respectively). The novel sol-gel hybrid MTMOS-TEOS SPE sorbent demonstrate the potential as an alternative inexpensive extraction sorbent for OPPs with higher sensitivity for the OPPs.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  4. Simultaneous determination of veterinary antibiotics and hormone in broiler manure, soil and manure compost by liquid chromatography-tandem mass spectrometry
    Ho YB, Zakaria MP, Latif PA, Saari N
    J Chromatogr A, 2012 Nov 2;1262:160-8.
    PMID: 23026257 DOI: 10.1016/j.chroma.2012.09.024
    A multi-residue analytical method was developed to quantify nine antibiotics and one hormone in soil, broiler manure and manure compost. The developed method was based on ultrasonic extraction with MeOH:ACN:EDTA:McIlvaine buffer, solid phase extraction (SPE) using HLB (3 cc/60 mg) cartridge, followed by instrumental analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with 25 min total run time. It was validated and tested on soil, broiler manure and manure compost samples and showed that the method is able to simultaneously detect and quantify the target analytes with good selectivity and sensitivity. The developed method was linear in a concentration range from its instrumental quantification limit (IQL) to 500 ng/mL, with correlation coefficients higher than 0.999. The overall method performance was good for the majority of the analytes, with recoveries range from 63% to 121% in all the sample matrices. The method quantification limit (MQL) for the 10 target analytes in the soil, broiler manure and manure compost samples were 2-10, 3-16 and 5-15 μg/kg dry weight (DW), respectively. The method has also included tilmicosin, an antibiotic known to be reported in the environment for the first time. The developed method was then applied on broiler manure samples and its relative manure amended agricultural soil samples to identify and quantify veterinary antibiotic and hormone residues in the environment. These analytes were detected in broiler manure and soil samples, with maximum concentrations reaching up to 78516.1 μg/kg DW (doxycycline) and 1331.4 μg/kg DW (flumequine), respectively. The results showed that the method can potentially be adopted for the analysis of veterinary antibiotic and hormone wastes in solid environmental matrices.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  5. Fulltext Detection of differential levels of proteins in the urine of patients with endometrial cancer: analysis using two-dimensional gel electrophoresis and o-glycan binding lectin
    Mu AK, Lim BK, Hashim OH, Shuib AS
    Int J Mol Sci, 2012;13(8):9489-501.
    PMID: 22949810 DOI: 10.3390/ijms13089489
    Cancers can cause some proteins to be aberrantly excreted or released in the urine, which can be used as biomarkers. To screen for potential biomarkers for endometrial cancer (ECa), the urinary proteins from patients who were newly diagnosed with early stage ECa and untreated controls were separated using two-dimensional gel electrophoresis (2-DE) and followed by image analysis. The altered levels of zinc alpha-2 glycoprotein, alpha 1-acid glycoprotein, and CD59 were detected in the patients compared to the controls. In addition, the urine of the ECa patients was also found to contain relatively lower levels of a fragment of nebulin when the 2-DE separated urinary proteins were probed using champedak galactose binding (CGB) lectin. The different levels of the nebulin fragment were further validated by subjecting the urinary protein samples to CGB lectin affinity chromatography and analysis of the bound fractions by LC-MS/MS. Our data is suggestive of the potential use of the differentially expressed urinary proteins as biomarkers for ECa although this requires further extensive validation on clinically representative populations.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  6. Fulltext Gas chromatography-mass spectrometry analysis of various organic extracts of Merremia borneensis from Sabah
    Hossain MA, Shah MD, Sakari M
    Asian Pac J Trop Med, 2011 Aug;4(8):637-41.
    PMID: 21914542 DOI: 10.1016/S1995-7645(11)60162-4
    OBJECTIVE: To analyse the chemical composition of different extracts of Merremia borneensis (M. borneensis) by gas chromatography-mass spectrometry (GC-MS).

    METHODS: The dried leaves powder was extracted with methanol at room temperature by using Soxhlet extractor. Methanol crude extracts of M. borneensis were extrastel with hexane, chloroform, ethyl acetate and butanol.

    RESULTS: Qualitative analyses of various organic crude extracts showed that majority of these are flavonoids, terpeniods, alkaloids and glycosides. Most of the identified compounds by GC-MS are biologically important. Further the M. borneensis leaf possesses certain characteristics that can be ascribed to cultivation on a domestic plantation.

    CONCLUSIONS: The suitable extracts for respective compounds can be chosen on the basis of above GC-MS analysis. All the major compounds from different extracts are biologically active molecules. Thus the identification of a good number of compounds from various extracts M. borneensis might have some ecological significance.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  7. Fulltext A biomimetic sensor for the classification of honeys of different floral origin and the detection of adulteration
    Zakaria A, Shakaff AY, Masnan MJ, Ahmad MN, Adom AH, Jaafar MN, et al.
    Sensors (Basel), 2011;11(8):7799-822.
    PMID: 22164046 DOI: 10.3390/s110807799
    The major compounds in honey are carbohydrates such as monosaccharides and disaccharides. The same compounds are found in cane-sugar concentrates. Unfortunately when sugar concentrate is added to honey, laboratory assessments are found to be ineffective in detecting this adulteration. Unlike tracing heavy metals in honey, sugar adulterated honey is much trickier and harder to detect, and traditionally it has been very challenging to come up with a suitable method to prove the presence of adulterants in honey products. This paper proposes a combination of array sensing and multi-modality sensor fusion that can effectively discriminate the samples not only based on the compounds present in the sample but also mimic the way humans perceive flavours and aromas. Conversely, analytical instruments are based on chemical separations which may alter the properties of the volatiles or flavours of a particular honey. The present work is focused on classifying 18 samples of different honeys, sugar syrups and adulterated samples using data fusion of electronic nose (e-nose) and electronic tongue (e-tongue) measurements. Each group of samples was evaluated separately by the e-nose and e-tongue. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were able to separately discriminate monofloral honey from sugar syrup, and polyfloral honey from sugar and adulterated samples using the e-nose and e-tongue. The e-nose was observed to give better separation compared to e-tongue assessment, particularly when LDA was applied. However, when all samples were combined in one classification analysis, neither PCA nor LDA were able to discriminate between honeys of different floral origins, sugar syrup and adulterated samples. By applying a sensor fusion technique, the classification for the 18 different samples was improved. Significant improvement was observed using PCA, while LDA not only improved the discrimination but also gave better classification. An improvement in performance was also observed using a Probabilistic Neural Network classifier when the e-nose and e-tongue data were fused.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods
  8. Identification of thioketone analogues of sildenfil using gas chromatography-mass spectrometry
    Man CN, Noor NM, Lajis R
    J Chromatogr A, 2011 Sep 28;1218(39):7055-60.
    PMID: 21872876 DOI: 10.1016/j.chroma.2011.08.037
    Sildenafil analogues have been found adulterated in herbal preparations and food products that claim to have natural aphrodisiacs. In this study, a gas chromatography-mass spectrometry (GC-MS) assay was developed for the screening and identification of thioketone analogues of sildenafil. Thiopyrazolopyrimidine, a precursor or a cleavage product of thioketone analogue, exhibited characteristic fragment ions of m/z 328 and m/z 299 was found to be the best marker to screen the presence of general thioketone analogues. Identification by GC-MS assay was rapid and specific as all the studied thioketones showed characteristic mass fragmentations including their intact molecular ions. The developed GC-MS assay had successfully identified thiosildenafil, thiohomosildenafil and thiodimethylsildenafil in herbal preparation and food products.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  9. A reversed phase high performance liquid chromatography method for the determination of fumonisins B1 and B2 in food and feed using monolithic column and positive confirmation by liquid chromatography/tandem mass spectrometry
    Khayoon WS, Saad B, Salleh B, Ismail NA, Abdul Manaf NH, Abdul Latiff A
    Anal Chim Acta, 2010 Oct 29;679(1-2):91-7.
    PMID: 20951862 DOI: 10.1016/j.aca.2010.09.008
    The development of a reversed phase high performance liquid chromatography fluorescence method for the determination of the mycotoxins fumonisin B(1) and fumonisin B(2) by using silica-based monolithic column is described. The samples were first extracted using acetonitrile:water (50:50, v/v) and purified by using a C(18) solid phase extraction-based clean-up column. Then, pre-column derivatization for the analyte using ortho-phthaldialdehyde in the presence of 2-mercaptoethanol was carried out. The developed method involved optimization of mobile phase composition using methanol and phosphate buffer, injection volume, temperature and flow rate. The liquid chromatographic separation was performed using a reversed phase Chromolith(®) RP-18e column (100 mm × 4.6 mm) at 30 °C and eluted with a mobile phase of a mixture of methanol and phosphate buffer pH 3.35 (78:22, v/v) at a flow rate of 1.0 mL min(-1). The fumonisins separation was achieved in about 4 min, compared to approximately 20 min by using a C(18) particle-packed column. The fluorescence excitation and emission were at 335 nm and 440 nm, respectively. The limits of detections were 0.01-0.04 μg g(-1) fumonisin B(1) and fumonisin B(2), respectively. Good recoveries were found for spiked samples (0.1, 0.5, 1.5 μg g(-1) fumonisins B(1) and B(2)), ranging from 84.0 to 106.0% for fumonisin B(1) and from 81.0 to 103.0% for fumonisin B(2). Fifty-three samples were analyzed including 39 food and feeds and 14 inoculated corn and rice. Results show that 12.8% of the food and feed samples were contaminated with fumonisin B(1) (range, 0.01-0.51 μg g(-1)) and fumonisin B(2) (0.05 μg g(-1)). The total fumonisins in these samples however, do not exceed the legal limits established by the European Union of 0.8 μg g(-1). Of the 14 inoculated samples, 57.1% contained fumonisin B(1) (0.16-41.0 μg g(-1)) and fumonisin B(2) (range, 0.22-50.0 μg g(-1)). Positive confirmation of selected samples was carried out using liquid chromatography-tandem mass spectrometry, using triple quadrupole analyzer and operated in the multiple reaction monitoring mode.
    Matched MeSH terms: Tandem Mass Spectrometry/methods
  10. Identification of sildenafil, tadalafil and vardenafil by gas chromatography-mass spectrometry on short capillary column
    Man CN, Nor NM, Lajis R, Harn GL
    J Chromatogr A, 2009 Nov 20;1216(47):8426-30.
    PMID: 19853256 DOI: 10.1016/j.chroma.2009.10.016
    Sildenafil and its analogues (tadalafil and vardenafil) are phosphodiesterase type 5 inhibitors used in the treatment of male erectile dysfunction. Some dietary supplements, herbal preparations and food products which claim to enhance male sexual function have been found to be adulterated with these drugs. In this study, a gas chromatograph-mass spectrometer (GC-MS) assay was developed for identification of the drugs. In addition to good and short chromatographic separation that can be achieved within 6 min by using a short 10 m capillary column, no prior sample clean-up before GC-MS analysis was required, thus making this assay a cost saving and rapid method. Furthermore, the assay is specific as the identification of sildenafil, tadalafil and vardenafil were done by detection of molecular ions; m/z 474, 389 and 488, [corrected] respectively, and several other characteristic ions resulted from the mass fragmentation of individual molecules. Using our currently developed assay, sildenafil and its analogues were successfully identified in food and herbal matrices.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  11. Relationship between markers of lipid peroxidation, thiol oxidation and Glasgow coma scale scores of moderate head injury patients in the 7 day post-traumatic period
    Nayak C, Nayak D, Raja A, Rao A
    Neurol Res, 2008 Jun;30(5):461-4.
    PMID: 18953735
    Epidemiologic works reveal that moderate head injury (MHI) is more frequent and a substantial number of these patients develop complications resulting in neurological disabilities. Reactive oxygen species (ROS) play a major role in post-traumatic neuronal damage following traumatic head injury. Thus, the current study analysed the post-traumatic changes in the erythrocyte markers of oxidative damage and the relationship between these parameters and Glasgow coma scale (GCS) scores of MHI patients during the 7 day study period.
    Matched MeSH terms: Mass Spectrometry/methods
  12. Structure-informed detection and quantification of peptides in food and biological fluids
    Agyei D, Pan S, Acquah C, Bekhit AEA, Danquah MK
    J Food Biochem, 2019 01;43(1):e12482.
    PMID: 31353495 DOI: 10.1111/jfbc.12482
    Peptides with biological properties, that is, bioactive peptides, are a class of biomolecules whose health-promoting properties are increasingly being exploited in food and health products. However, research on targeted techniques for the detection and quantification of these peptides is still in its infancy. Such information is needed in order to enhance the biological and chemometric characterization of peptides and their subsequent application in the functional food and pharmaceutical industries. In this review, the role of classic techniques such as electrophoretic, chromatographic, and peptide mass spectrometry in the structure-informed detection and quantitation of bioactive peptides are discussed. Prospects for the use of aptamers in the characterization of bioactive peptides are also discussed. PRACTICAL APPLICATIONS: Although bioactive peptides have huge potential applications in the functional foods and health area, there are limited techniques in enhancing throughput detection, quantification, and characterization of these peptides. This review discusses state-of-the-art techniques relevant in complementing bioactive detection and profiling irrespective of the small number of amino acid units. Insights into challenges, possible remedies and prevailing areas requiring thorough research in the extant literature for food chemists and biotechnologists are also presented.
    Matched MeSH terms: Mass Spectrometry/methods
  13. Metabolism studies of the Kratom alkaloid speciociliatine, a diastereomer of the main alkaloid mitragynine, in rat and human urine using liquid chromatography-linear ion trap mass spectrometry
    Philipp AA, Wissenbach DK, Weber AA, Zapp J, Maurer HH
    Anal Bioanal Chem, 2011 Mar;399(8):2747-53.
    PMID: 21249338 DOI: 10.1007/s00216-011-4660-9
    Mitragyna speciosa (Kratom) is currently used as a drug of abuse. When monitoring its abuse in urine, several alkaloids and their metabolites must be considered. In former studies, mitragynine (MG), its diastereomer speciogynine (SG), and paynantheine and their metabolites could be identified in rat and human urine using LC-MS(n). In Kratom users' urines, besides MG and SG, further isomeric compounds were detected. To elucidate whether the MG and SG diastereomer speciociliatine (SC) and its metabolites represent further compounds, the phase I and II metabolites of SC were identified first in rat urine after the administration of the pure alkaloid. Then, the identified rat metabolites were screened for in the urine of Kratom users using the above-mentioned LC-MS(n) procedure. Considering the mass spectra and retention times, it could be confirmed that SC and its metabolites are so far the unidentified isomers in human urine. In conclusion, SC and its metabolites can be used as further markers for Kratom use, especially by consumption of raw material or products that contain a high amount of fruits of the Malaysian plant M. speciosa.
    Matched MeSH terms: Mass Spectrometry/methods*
  14. Anti-Proliferative Effects of Methanol and Water Extracts of Pyrrosia piloselloides on the Hela Human Cervical Carcinoma Cell Line
    Sul ‘ain MD, Zakaria F, Johan MF
    Asian Pac J Cancer Prev, 2019 Jan 25;20(1):185-192.
    PMID: 30678430
    Background: Cervical cancer is one of the most commonly diagnosed neoplasms and a leading cause of cancer
    death among females worldwide. Limitations with conventional medical treatments have driven researchers to
    search for alternative approaches using natural products. This study aimed to detemine potential anti-proliferative
    effects of methanol and water extracts of Pyrrosia piloselloides (P. piloselloides) on the HeLa cell line. Methods:
    3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to determine IC50
    concentrations and apoptosis analysis was by flow cytometry. To identify chemical compounds in the extracts, gas
    chromatography-mass spectrometry (GC-MS) was employed. Results: P. piloselloides methanol extracts (PPME) showed
    antiproliferative effects on HeL awith an IC50 of 16.25μg/mL while the P. piloselloides water extract (PPWE) was without
    influence. Neither extract showed any significant effects on apoptosis. GC-MS analysis, revealed 5-hydroxymethylfurfural
    (23.1%), allopurinol (8.66%) and 3, 5-dihydroxy-6-methyl-2,3-dihydropyran-4-one (7.41%) as major components in
    the PPME, while sulfolan-3-ol (10.1%), linoleic acid (9.06%) and β-sitosterol acetate (7.98%) predominated in the
    PPWE case. Conclusion: This first study of P. piloselloides showed PPME to exert potent anti-proliferative effect on
    HeLa cell lines. Further research now needs to be performed to establish the mechanisms of inhibition.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods
  15. Fulltext Pharmacokinetics and Metabolism of Liposome-Encapsulated 2,4,6-Trihydroxygeranylacetophenone in Rats Using High-Resolution Orbitrap Liquid Chromatography Mass Spectrometry
    Alkhateeb Y, Jarrar QB, Abas F, Rukayadi Y, Tham CL, Hay YK, et al.
    Molecules, 2020 Jul 06;25(13).
    PMID: 32640512 DOI: 10.3390/molecules25133069
    2,4,6-trihydroxy-3-geranylacetophenone (tHGA) is a bioactive compound that shows excellent anti-inflammatory properties. However, its pharmacokinetics and metabolism have yet to be evaluated. In this study, a sensitive LC-HRMS method was developed and validated to quantify tHGA in rat plasma. The method showed good linearity (0.5-80 ng/mL). The accuracy and precision were within 10%. Pharmacokinetic investigations were performed on three groups of six rats. The first two groups were given oral administrations of unformulated and liposome-encapsulated tHGA, respectively, while the third group received intraperitoneal administration of liposome-encapsulated tHGA. The maximum concentration (Cmax), the time required to reach Cmax (tmax), elimination half-life (t1/2) and area under curve (AUC0-24) values for intraperitoneal administration were 54.6 ng/mL, 1.5 h, 6.7 h, and 193.9 ng/mL·h, respectively. For the oral administration of unformulated and formulated tHGA, Cmax values were 5.4 and 14.5 ng/mL, tmax values were 0.25 h for both, t1/2 values were 6.9 and 6.6 h, and AUC0-24 values were 17.6 and 40.7 ng/mL·h, respectively. The liposomal formulation improved the relative oral bioavailability of tHGA from 9.1% to 21.0% which was a 2.3-fold increment. Further, a total of 12 metabolites were detected and structurally characterized. The metabolites were mainly products of oxidation and glucuronide conjugation.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  16. Fulltext Liquid Chromatographic Tandem Mass Spectrometric (LC-MS/MS) Determination of Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA) in the Yolk of Poultry Eggs in Malaysia
    Tahziz A, Mohamad Haron DE, Aziz MY
    Molecules, 2020 May 16;25(10).
    PMID: 32429475 DOI: 10.3390/molecules25102335
    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are widely used in products, and are known for their water and grease repellent properties. The persistence nature and potential toxicity of these substances have raised substantial concerns about health effects. Regarding humans, food consumption has reportedly been a significant source of exposure for both compounds. Hence, this study was performed to develop and validate an analytical method for PFOS and PFOA in egg yolks using liquid chromatographic tandem mass spectrometry (LC-MS/MS) followed by the determination of concentration of both compounds in the yolk of poultry eggs in Malaysia. A total of 47 poultry egg yolk samples were extracted by a simple protein precipitation technique using acetonitrile. The analytical method was developed using LC-MS/MS and validated based on the Food and Drug Administration (FDA)'s Bioanalytical Method Validation guidelines. The results revealed that PFOS was quantitatively detected in six samples, with the concentration range between 0.5 and 1.01 ng g-1. Among these, five samples were from home-produced chicken eggs, and one sample was from a quail egg. The levels of PFOA in all samples were below the quantifiable limit (<0.1 ng g-1). This indicated that the contamination of PFCs in poultry eggs were mostly attributed to the nature of free foraging animals, which had direct contact with the contaminants in soil and feed. In conclusion, a fast and robust analytical method for analyzing PFOS and PFOA in egg yolk samples using LC-MS/MS was successfully developed and validated. The presence of these emerging contaminants in this study signified widespread pollution in the environment.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  17. Fulltext Communal microaerophilic-aerobic biodegradation of Amaranth by novel NAR-2 bacterial consortium
    Chan GF, Rashid NA, Chua LS, Ab llah N, Nasiri R, Ikubar MR
    Bioresour Technol, 2012 Feb;105:48-59.
    PMID: 22182471 DOI: 10.1016/j.biortech.2011.11.094
    A novel bacterial consortium, NAR-2 which consists of Citrobacter freundii A1, Enterococcus casseliflavus C1 and Enterobacter cloacae L17 was investigated for biodegradation of Amaranth azo dye under sequential microaerophilic-aerobic condition. The NAR-2 bacterial consortium with E. casseliflavus C1 as the dominant strain enhanced the decolorization process resulting in reduction of Amaranth in 30 min. Further aerobic biodegradation, which was dominated by C. freundii A1 and E. cloacae L17, allowed biotransformation of azo reduction intermediates and mineralization via metabolic pathways including benzoyl-CoA, protocatechuate, salicylate, gentisate, catechol and cinnamic acid. The presence of autoxidation products which could be metabolized to 2-oxopentenoate was elucidated. The biodegradation mechanism of Amaranth by NAR-2 bacterial consortium was predicted to follow the steps of azo reduction, deamination, desulfonation and aromatic ring cleavage. This is for the first time the comprehensive microaerophilic-aerobic biotransformation pathways of Amaranth dye intermediates by bacterial consortium are being proposed.
    Matched MeSH terms: Tandem Mass Spectrometry/methods
  18. Fulltext RP-UHPLC-MS Chemical Profiling, Biological and In Silico Docking Studies to Unravel the Therapeutic Potential of Heliotropium crispum Desf. as a Novel Source of Neuroprotective Bioactive Compounds
    Arshad A, Ahemad S, Saleem H, Saleem M, Zengin G, Abdallah HH, et al.
    Biomolecules, 2021 01 04;11(1).
    PMID: 33406643 DOI: 10.3390/biom11010053
    Heliotropium is one of the most important plant genera to have conventional folklore importance, and hence is a potential source of bioactive compounds. Thus, the present study was designed to explore the therapeutic potential of Heliotropium crispum Desf., a relatively under-explored medicinal plant species. Methanolic extracts prepared from a whole plant of H. crispum were studied for phytochemical composition and possible in vitro and in silico biological properties. Antioxidant potential was assessed via six different assays, and enzyme inhibition potential against key clinical enzymes involved in neurodegenerative diseases (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)), diabetes (α-amylase and α-glucosidase), and skin problems (tyrosinase) was assayed. Phytochemical composition was established via determination of the total bioactive contents and reverse phase ultra-high performance liquid chromatography mass spectrometry (RP-UHPLC-MS) analysis. Chemical profiling revealed the tentative presence of 50 secondary metabolites. The plant extract exhibited significant inhibition against AChE and BChE enzymes, with values of 3.80 and 3.44 mg GALAE/g extract, respectively. Further, the extract displayed considerable free radical scavenging activity against DPPH and ABTS radicals, with potential values of 43.19 and 41.80 mg TE/g extract, respectively. In addition, the selected compounds were then docked against the tested enzymes, which have shown high inhibition affinity. To conclude, H. crispum was found to harbor bioactive compounds and showed potent biological activities which could be further explored for potential uses in nutraceutical and pharmaceutical industries, particularly as a neuroprotective agent.
    Matched MeSH terms: Mass Spectrometry*
  19. Magnetic molecularly imprinted polymer nanoparticles for the extraction and clean-up of thiamethoxam and thiacloprid in light and dark honey
    Abdulhussein AQ, Jamil AKM, Bakar NKA
    Food Chem, 2021 Oct 15;359:129936.
    PMID: 33957328 DOI: 10.1016/j.foodchem.2021.129936
    In this work, new selective and sensitive dual-template molecularly imprinted polymer nanoparticles (MIPs) were synthesized and characterized. Sorbent MIPs were investigated for simultaneous extraction and clean-up of thiamethoxam and thiacloprid from light and dark honey samples. In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry triple-quadrupole (UHPLC-MS/MS) (QQQ) was used to detect and quantify the pesticides. The kinetic model with adsorption kinetics of sorbent was investigated. The optimal adsorption conditions were 80 mg of polymer MIPs, a 30-min extraction time, and a pH of 7. The detection limit (LOD) and the quantification limit (LOQ) varied from 0.045 to 0.070 µg kg-1 and from 0.07 to 0.10 µg kg-1, respectively. The intra-day and inter-day precision (RSD, %) ranged from 1.3 to 2.0% and from 8.2 to 12.0%, respectively. The recovery of thiamethoxam and thiacloprid ranged from 96.8 to 106.5% and 95.3 to 104.4%, respectively, in light and dark honey samples.
    Matched MeSH terms: Tandem Mass Spectrometry/methods
  20. Fulltext Mass spectrometry-based proteomic platforms for better understanding of SARS-CoV-2 induced pathogenesis and potential diagnostic approaches
    Ahsan N, Rao RSP, Wilson RS, Punyamurtula U, Salvato F, Petersen M, et al.
    Proteomics, 2021 05;21(10):e2000279.
    PMID: 33860983 DOI: 10.1002/pmic.202000279
    While protein-protein interaction is the first step of the SARS-CoV-2 infection, recent comparative proteomic profiling enabled the identification of over 11,000 protein dynamics, thus providing a comprehensive reflection of the molecular mechanisms underlying the cellular system in response to viral infection. Here we summarize and rationalize the results obtained by various mass spectrometry (MS)-based proteomic approaches applied to the functional characterization of proteins and pathways associated with SARS-CoV-2-mediated infections in humans. Comparative analysis of cell-lines versus tissue samples indicates that our knowledge in proteome profile alternation in response to SARS-CoV-2 infection is still incomplete and the tissue-specific response to SARS-CoV-2 infection can probably not be recapitulated efficiently by in vitro experiments. However, regardless of the viral infection period, sample types, and experimental strategies, a thorough cross-comparison of the recently published proteome, phosphoproteome, and interactome datasets led to the identification of a common set of proteins and kinases associated with PI3K-Akt, EGFR, MAPK, Rap1, and AMPK signaling pathways. Ephrin receptor A2 (EPHA2) was identified by 11 studies including all proteomic platforms, suggesting it as a potential future target for SARS-CoV-2 infection mechanisms and the development of new therapeutic strategies. We further discuss the potentials of future proteomics strategies for identifying prognostic SARS-CoV-2 responsive age-, gender-dependent, tissue-specific protein targets.
    Matched MeSH terms: Mass Spectrometry/methods*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links