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Magnetically driven separation technology has received considerable attention in recent decade for its great potential application. In this study, we investigate the application of silica-modified magnetite nanoparticles (NPs) coated with a cationic surfactant as adsorbent for microextraction and determination of trace amounts of Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) from environmental...
A new method of quantitative incorporation of primary cations into ion-selective membrane by means of galvanostatic cathodic polarization/conditioning, before measurement step, was proposed and tested on the example of potassium-selective electrode with ionophore – valinomycin in poly(vinyl chloride) based membrane and with polypyrrole solid contact. Open circuit potential values recorded after polarization...
Analysis of metal ions in environment is of great importance for evaluating the risk of heavy metal to public health and ecological safety. A method for simultaneous determination of metal ions in water samples was developed by using adsorption preconcentration and near-infrared diffuse reflectance spectroscopy (NIRDRS). A high capacity adsorbent of thiol-functionalized magnesium phyllosilicate, named...
This work proposes the use of digital image-based method for determination of total acidity in red wines by means of acid–base titration without using an external indicator or any pre-treatment of the sample. Digital images present the colour of the emergent radiation which is complementary to the radiation absorbed by anthocyanines present in wines. Anthocyanines change colour depending on the pH...
The use of rod-like and vesicle-like mesoporous SiO 2 particles for fabricating high performance glucose biosensors is reported. The distinctively high surface areas of mesoporous structures of SiO 2 rendered the adsorption of glucose oxidase (GOx) feasible. Both morphologies of SiO 2 enhanced the sensitivities of glucose biosensors, but by a factor of 36 for vesicle-like SiO...
A novel, quantitative analytical method for measuring C-reactive protein (CRP) levels in human serum has been developed based on the catalytic activity of gold nanoparticles (GNPs) and luminol–H 2 O 2 chemiluminescence (CL). The CL intensity in the presence of CRP and its ligand, O-phosphorylethanolamine (PEA), was greatly enhanced due to the aggregation of GNPs after the addition...
This work is a study of the analytical utility of Nafion-modified microfabricated bismuth film electrodes (BiFEs) for the determination of Pb(II) and Cd(II) by anodic stripping voltammetry (ASV) in the presence of surfactants. Micro-fabricated BiFEs were prepared by depositing a thin film of bismuth on the surface of a silicon substrate by sputtering while the two-dimensional geometry of the final...
The spatial inhomogeneity of anions in ambient particulate matter collected on filters has been investigated using two different sub-sampling techniques and with analysis by a drift-corrected ion chromatography technique. The results highlight the inhomogeneity in anion mass along the radius of the sampled filter, in agreement with analogous studies on metals in PM, and also, more surprisingly, significant...
The design and construction of a highly selective voltammetric sensor for metronidazole by using a molecularly imprinted polymer (MIP) as recognition element were introduced. A metronidazole selective MIP and a nonimprinted polymer (NIP) were synthesized and then incorporated in the carbon paste electrodes (CPEs). The sensor was applied for metronidazole determination using cathodic stripping voltammetric...
Magnetic nanoparticles (MNPs) have been receiving increasing attention because of its great potentials in bioseparation. However, the separation products are difficult to be detected by general method due to their extremely small size. Here, we demonstrate that MNPs can greatly enhance the signal of surface plasmon resonance spectroscopy (SPR). Features of MNPs–aptamer conjugates as a powerful amplification...
A novel fluorimetric method is described for the evaluation of the antioxidant activity of hydrophilic and lipophilic compounds and complex natural products such as edible oils. The method is based on the measurement of fluorescence emission intensity of N-methylacridone produced during the reaction of lucigenin with hydrogen peroxide. The presence of antioxidants in the sample inhibits the concentration...
In the present work, two morphologies of SiO 2 nanomaterials (SiO 2 nanotubes and nanoparticles) have been successfully synthesized in supercritical fluids (SCFs). The cataluminescence (CTL) features of the two SiO 2 nanomaterials to some common harmful gases were compared, and the results showed that SiO 2 nanotubes had better CTL sensing characteristic to some common...
A method for the determination of sulfur in biodiesel samples by inductively coupled plasma optical emission spectrometry which uses microemulsion for sample preparation and the summation of the intensities of multiple emission lines has been developed. Microemulsions were prepared using 0.5mL of 20% v/v HNO 3 , 0.5mL of Triton X-100, 2–3mL of biodiesel sample, and diluted with n-propanol...
We present the fabrication of a microdevice for the detection of phenol by combining microfluidic channels and poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel microparticles containing tyrosinase–quantum dot conjugates. PHEMA hydrogel microparticles containing conjugates of enzyme (tyrosinase) and quantum dot (QD) were prepared by dispersion photopolymerization and entrapped within a microfilter-incorporated...
A method based on laser induced breakdown spectroscopy (LIBS) and neural networks (NNs) has been developed and applied to the identification and discrimination of specific bacteria strains (Pseudomonas aeroginosa, Escherichia coli and Salmonella typhimurium). Instant identification of the samples is achieved using a spectral library, which was obtained by analysis using a single laser pulse of representative...
2,4,6-trichloroanisole (TCA) is a microbial metabolite formed from chlorophenols through the activity of several natural fungal strains present on the cork oak bark. TCA is the primary compound responsible for the mousty/mould off-odour known as “cork taint” present in cork stoppers, wine, water and alcoholic beverages. Chromatographic and electrochemical methods are currently used for the determination...
An effective method for peptide sequencing based on phosphorylation strategy and UPLC–MS/MS is proposed in this report. A phosphorylation reaction was carried out by mixing model peptide solution with phosphorylation solution. UPLC–MS/MS was used to analyze and characterize the phosphorylated peptides in the optimized ramp collision energy mode. The results illustrated that this phosphorylation approach...
A multiplexed capillary electrophoresis (CE) system equipped with 96 channels was evaluated for high-throughput screening in drug discovery by microemulsion electrokinetic chromatography (MEEKC). Method transfer from a single channel to a multichannel CE system is described. Loss of efficiency and reduced migration times could be elucidated to the poor efficacy in Joule heat dissipation by forced...
Solid-phase extraction (SPE) combined with liquid chromatography electrospray mass spectrometry (LC–(ESI)MS) was used to determine 16 non-ionic and anionic surfactants in different environmental water samples at ngL −1 levels. The proposed method is sensitive and simple and has good linear range and detection limits (less than 50ngL −1 ) for most compound classes.The effect of ion...
The supramolecular interaction of cucurbit(n=7)uril (Q[7]) with berberine chloride (BER) has been studied in aqueous solution at pH 2.0 and room temperature by spectro-fluorimetry. The association constant of the complex was 2.07×10 6 Lmol −1 calculated by using a nonlinear least squares method. 1 H NMR spectra confirmed that a 1:1 stable complex is formed between Q[7] and...
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