Determination of phenanthrene and fluoranthene in rice samples by activated carbon-based dispersive solid phase micro-extraction coupled with gas chromatography-flame ionization detector analysis

A simple dispersive solid phase micro-extraction (DSPME) based on activated carbon (AC) was performed for the determination and separation of carcinogenic polycyclic aromatic hydrocarbons (PAHs), namely phenanthrene and fluoranthene, in selected white, brown and parboiled rice samples. The extraction was coupled with gas chromatography-flame ionization detector (GC-FID) for analysis. Under the optimized conditions [amount of adsorbent (5 mg), sample volume (40 mL), type (dichloromethane), and volume of desorption solvent (300 μL)], calibration curves were found to be linear for the concentration between 10 and 1000 μg kg-1 with coefficient of determination (R2) from 0.9938 to 0.9955. The limit of detection (LOD) and limit of quantification (LOQ) were in the range of 0.11 - 0.15 μg kg-1 and 0.33 - 0.46 μg kg-1, respectively. Relative standard deviation (RSD) was less than 8.02% and 5.48% for intra-day (n = 5) and inter-day (n = 5) for the present method, respectively. High pre-concentration factor (2587 - 2866) and satisfactory recoveries (90.23 - 115.63%) were also achieved. The proposed method was found to be simple, rapid and reliable for the monitoring of PAHs in rice samples

Inclusion of curcumin in β-cyclodextrins as potential drug delivery system: preparation, characterization and its preliminary cytotoxicity approaches

The development and application of organic based drug carrier in drug delivery system (DDSs) with greater efficacy and fewer side effects remains a significant challenge in modern scientific and medical research. The aim of current study was to evaluate the ability of β-cyclodextrin (β-CD) as drug delivery carrier to encapsulate Curcumin (CUR), a promising chemotherapeutic that exhibits low aqueous solubility and poor bioavailability forming inclusion complex by kneading method to enhance its delivery to cancer cells. Different methods and analysis such as Fourier Transform Infrared (FTIR) spectrometer, 1H Nuclear Magnetic Resonance (1H NMR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Thermo-gravimetric Analysis (TGA) were employed to approve the successful formation of the inclusion complex where the aromatic ring of CUR has been encapsulated by the hydrophobic cavity of β-CD. UV absorption indicated that β-CD complex with CUR with an apparent formation constant of 1.09 × 10-8mol-1dm-3. Based on the data obtained by methylthiazole tetrazolium (MTT), β-CD showed that not only did it enhanced Curcumin delivery, but it also improved and promoted the anti-proliferative effect of CUR during the complexation rather than CUR alone on the MCF-7 human breast cancer cells at 24 h incubation period with IC50 lower than that of Curcumin alone. The toxicities of the β-CD-CUR towards MCF-7 cells were also compared to the free tamoxifen, Curcumin and β-CD. This study provides a preliminary toxicity evaluation based on β-CD-CUR inclusion complex as potential delivery system towards the selected cancer cells

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Development Of Poly(Β-Cyclodextrin Functionalized Ionic Liquid) Conjugated Magnetic Nanoparticles As An Adsorbent For Microextraction Of Polycyclic Aromatic Hydrocarbons From Food Samples

Food contamination is a global food safety issue which pose a health concern. Analysis of food contaminants is essential to ensure consumer safety and compliance with regulatory limits. Thus, development of simple, miniaturize, and sensitive sample preparation techniques are always a choice of interest. This study aims to develop and investigate new nanomaterial, namely poly(βCD-IL)@Fe3O4 and their applications in the microextraction of low and high molecular weight polycyclic aromatic hydrocarbons (PAHs) that have been listed as priority pollutants by European Community (EC) and Environmental Protection Agency (EPA). In the first part of study, poly(βCD-IL)@Fe3O4 was successfully synthesized and characterized by various techniques including FT-IR, CHN elemental analysis, XRD, TEM, SEM, VSM, BET, TGA, DSC, zeta potential and wettability measurement. Thereafter, poly(βCD-IL)@Fe3O4 was applied in magnetic μ-SPE technique as an adsorbent coupled with gas chromatographic-flame ionization detection (magnetic μSPE-GC-FID) for the determination of five selected low molecular weight PAHs in rice samples. Under optimized conditions, the calibration curves were linear for the concentration ranging between 0.1 and 500 μg kg-1 with coefficient of determination (R2) from 0.9970 to 0.9982 for all analytes. Detection limits (LODs) ranged at 0.01–0.18 μg kg-1 in real matrix. The RSD values ranged at 2.95%–5.34% (intra-day, n=6) and 4.37%–7.05% (inter-day, n=6). The sorbent showed satisfactory reproducibility in 2.9% to 9.9% range and acceptable recovery values at 80.4%–112.4% for the real samples

Magnetic poly(β-cyclodextrin-ionic liquid) nanocomposites for micro-solid phase extraction of selected polycyclic aromatic hydrocarbons in rice samples prior to GC-FID analysis

Poly(β-cyclodextrin functionalized ionic liquid) immobilized magnetic nanoparticles (Fe3O4@βCD-Vinyl-TDI) as sorbent in magnetic µ-SPE was developed for the determination of selected polycyclic aromatic hydrocarbons (PAHs) in rice samples coupled with gas chromatographic-flame ionization detector (GC-FID). The nanocomposite was characterized by various tools and significant parameters that affected the extraction efficiency of PAHs were investigated. The calibration curves were linear for the concentration ranging between 0.1 and 500 μg kg−1 with correlation determinations (R2) from 0.9970 to 0.9982 for all analytes. Detection limits ranged at 0.01–0.18 μg kg−1 in real matrix. The RSD values ranged at 2.95%–5.34% (intra-day) and 4.37%–7.05% (inter-day) precision for six varied days. The sorbents showed satisfactory reproducibility in 2.9% to 9.9% range and acceptable recovery values at 80.4%–112.4% were obtained for the real sample analysis. The optimized method was successfully applied to access content safety of selected PAHs for 24 kinds of commercial rice available in Malaysia

Poly(cyclodextrin-ionic liquid) based ferrofluid: A new class of magnetic colloid for dispersive liquid phase microextraction of polycyclic aromatic hydrocarbons from food samples prior to GC-FID analysis

Poly(β-cyclodextrin-ionic liquid) grafted magnetic nanoparticles combined with 1-octanol as supramolecular solvents (SUPRASs) presenting new ferrofluid was developed and successfully applied in the dispersive liquid-phase microextraction of seven representative polycyclic aromatic hydrocarbons. One variable at-a-time (OVAT) analysis and response surface methodology (RSM) were used for efficient optimization of the main variables. The calibration curves were found to be linear in the range of 0.1–150 ng mL−1 with correlation of determinations (R2) ranging from 0.9944 to 0.9986. Detection limits ranged at 0.02–0.07 ng mL−1 for all studied PAHs. The intra and inter-day precision values (RSD %) were in the range of 1.80%–7.56% and 2.97%–8.23%, respectively. The ferrofluid showed a satisfactory reproducibility between 1.72% and 5.90%, and acceptable recovery values at 84%–110% were obtained for the real samples analysis. The optimized method was successfully applied to access the content safety of the PAHs studied in a variety of commercial food and beverages available in Malaysia. © 2020 Elsevier Lt

Enantiomeric separation of azole antifungal compounds using chromatographic and electrophoretic techniques: a mini review

The separation of azole antifungal chiral compounds has gaining much interests since 1980’s as they possess different biological, pharmaceutical, and pharmacokinetic behaviors at various toxicity levels. Numerous studies have looked into this subject matter, and therefore, this review presents an overview on different chiral separation techniques that have been developed such as liquid chromatography (LC), gas chromatography (GC), supercritical fluid chromatography (SFC), and capillary electrophoresis (CE). This comprehensive review also discusses the mechanisms of the developed analytical methods such as preparation techniques and optimization parameters towards the enantioseparation performances as well as their advantages and drawbacks. Lastly, the conclusion and future directions of the chiral separation, particularly for azole compounds are provided accordingly

β-Cyclodextrin conjugated bifunctional isocyanate linker polymer for enhanced removal of 2,4-dinitrophenol from environmental waters

In this work, we reported the synthesis, characterization and adsorption study of two b-cyclodextrin (bCD) cross-linked polymers using aromatic linker 2,4-toluene diisocyanate (2,4-TDI) and aliphatic linker 1,6-hexamethylene diisocyanate (1,6-HDI) to form insoluble bCD-TDI and bCD-HDI. The adsorption of 2,4-dinitrophenol (DNP) on both polymers as an adsorbent was studied in batch adsorption experiments. Both polymers were well characterized using various tools that include Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer-Emmett-Teller analysis and scanning electron microscopy, and the results obtained were compared with the native bCD. The adsorption isotherm of 2,4-DNP onto polymers was studied. It showed that the Freundlich isotherm is a better fit for bCD-TDI, while the Langmuir isotherm is a better fit for bCD-HMDI. The pseudo-second-order kinetic model represented the adsorption process for both of the polymers. The thermodynamic study showed that bCD-TDI polymer was more favourable towards 2,4-DNP when compared with bCD-HDI polymer. Under optimized conditions, both bCD polymers were successfully applied on various environmental water samples for the removal of 2,4-DNP. bCD-TDI polymer showed enhanced sorption capacity and higher removal efficiency (greater than 80%) than bCD-HDI (greater than 70%) towards 2,4-DNP. The mechanism involved was discussed, and the effects of cross-linkers on bCD open up new perspectives for the removal of toxic contaminants from a body of water

Smart combination of β-cyclodextrin polymer-conjugated magnetic nanosorbent for potential adsorption of deoxyribonucleic acid

We reported the synthesis and characterization of Fe 3 O 4 magnetic nanoparticles modified β-cyclodextrin polymer (MNP@βCD-TDI) for the adsorption of deoxyribonucleic acid (DNA). The synthesized MNP@βCD-TDI was characterized by Fourier Transform Infra-Red spectroscopy and Vibrating Sample Magnetometer. Experiments were performed in a batch mode and parameters that affected the DNA adsorption were investigated. An evaluation of the adsorption behavior revealed that Freundlich model and pseudo-second-order fit the equilibrium data. The adsorption efficiency of DNA was found to be at 70 ± 5 % after being recycled three times. This study could be used as a general platform for future work on DNA adsorption and enrichment