A rapid MCM-41 dispersive micro-solid phase extraction coupled with LC/MS/MS for quantification of ketoconazole and voriconazole in biological fluids

A rapid dispersive micro-solid phase extraction (D-μ-SPE) combined with LC/MS/MS method was developed and validated for the determination of ketoconazole and voriconazole in human urine and plasma samples. Synthesized mesoporous silica MCM-41 was used as sorbent in D-μ-SPE of the azole compounds from biological fluids. Important D-μ-SPE parameters, namely type desorption solvent, extraction time, sample pH, salt addition, desorption time, amount of sorbent and sample volume were optimized. Liquid chromatographic separations were carried out on a Zorbax SB-C18 column (2.1 × 100 mm, 3.5 µm), using a mobile phase of acetonitrile – 0.05% formic acid in 5 mM ammonium acetate buffer (70:30, v/v). A triple quadrupole mass spectrometer with positive ionization mode was used for the determination of target analytes. Under the optimized conditions, the calibration curves showed good linearity in the range of 0.1 – 10000 µg/L with satisfactory LODs (≤ 0.06 µg/L) and LOQ (≤ 0.3 µg/L). The proposed method also showed acceptable intra- and inter-day precisions for ketoconazole and voriconazole from urine and human plasma with RSD% ≤ 16.5% and good relative recoveries in the range of 84.3 – 114.8%. MCM-41-D-μ-SPE method proved to be rapid, simple and requires a small volume of organic solvent (200 μL) and thus advantageous for routine drug analysis.



Ultrasensitive Fluorescent Probes Reveal an Adverse Action of Dipeptide Peptidase IV and Fibroblast Activation Protein during Proliferation of Cancer Cells

Analytical ChemistryDOI: 10.1021/acs.analchem.6b02231



LOC-SERS: A Promising Closed System for the Identification of Mycobacteria

Analytical ChemistryDOI: 10.1021/acs.analchem.6b01152



Effect of a Dual Charge on the DNA-Conjugated Redox Probe on DNA Sensing by Short Hairpin Beacons Tethered to Gold Electrodes

Analytical ChemistryDOI: 10.1021/acs.analchem.6b01020



Probing Distinct Fullerene Formation Processes from Carbon Precursors of Different Sizes and Structures

Analytical ChemistryDOI: 10.1021/acs.analchem.6b02076



Dual-Modal Colorimetric/Fluorescence Molecular Probe for Ratiometric Sensing of pH and Its Application

Analytical ChemistryDOI: 10.1021/acs.analchem.6b02398



Screening Oligosaccharide Libraries against Lectins Using the Proxy Protein Electrospray Ionization Mass Spectrometry Assay

Analytical ChemistryDOI: 10.1021/acs.analchem.6b02044



Developing an Acidic Residue Reactive and Sulfoxide-Containing MS-Cleavable Homobifunctional Cross-Linker for Probing Protein–Protein Interactions

Analytical ChemistryDOI: 10.1021/acs.analchem.6b02240



Graphene-Mediated Microfluidic Transport and Nebulization via High Frequency Rayleigh Wave Substrate Excitation

Lab Chip, 2016, Accepted ManuscriptDOI: 10.1039/C6LC00780E, PaperKar Man Ang, Leslie Yeo, Yew Mun Hung, Ming Kwang TanThe deposition of a thin graphene film atop a chipscale piezoelectric substrate on which surface acoustic waves are excited is observe…



Method to evaluate the quality of herbal medicines based on the dynamic changes of chemical compounds and pharmacological activity

Quality control has been one of the key scientific issues in the modernization of traditional Chinese medicine. This study explored a novel method for quality evaluation of herbal medicines. HPLC fingerprints and osteoblast proliferation activity of 1…



Comparison of critical methods developed for fatty acid analysis: A review

Fatty acids are important nutritional substances and metabolites in living organisms. These acids are abundant in Chinese herbs, such as Brucea javanica, Notopterygium forbesii, Isatis tinctoria, Astragalus membranaceus, and Aconitum szechenyianum. Th…



Rapid in situ growth of oriented titanium-nickel oxide composite nanotubes arrays coated on a Nitinol wire as a solid-phase microextraction fiber coupled to HPLC–UV

An oriented titanium-nickel oxide composite nanotubes coating was in situ grown on a Nitinol wire by direct electrochemical anodization in ethylene glycol with ammonium fluoride and water for the first time. The morphology and the composition of the r…



Rapid magnetic solid-phase extraction of Congo Red and Basic Red 2 from aqueous solution by ZIF-8@CoFe2O4 hybrid composites

Core–shell metal–organic framework materials have attracted considerable attention mainly due to their enhanced or new physicochemical properties compared with their single-component counterparts. In this work, a core–shell heterostructure of Co…



Magnetic porous carbon derived from a metal–organic framework as a magnetic solid-phase extraction adsorbent for the extraction of sex hormones from water and human urine

An iron-embedded porous carbon material (MIL-53-C) was fabricated by the direct carbonization of MIL-53. The MIL-53-C possesses a high surface area and good magnetic behavior. The structure, morphology, magnetic property, and porosity of the MIL-53-C …



Imidazolium-embedded iodoacetamide-functionalized silica-based stationary phase for hydrophilic interaction/reversed-phase mixed-mode chromatography

A novel imidazolium-embedded iodoacetamide-functionalized silica-based stationary phase has been prepared by surface radical chain-transfer polymerization. Then stationary phase was characterized by Fourier transform infrared spectrometry, thermogravi…



Signal-Amplified Near-Infrared Ratiometric Electrochemiluminescence Aptasensor Based on Multiple Quenching and Enhancement Effect of Graphene/Gold Nanorods/G-Quadruplex

Analytical ChemistryDOI: 10.1021/acs.analchem.6b01935



Multifunctional nanoprobe for cancer cell targeting and simultaneous fluorescence/magnetic resonance imaging

Publication date: Available online 28 July 2016
Source:Analytica Chimica Acta
Author(s): Zhenzhen Wei, Yafeng Wu, Yuewu Zhao, Li Mi, Jintao Wang, Jimin Wang, Jinjin Zhao, Lixin Wang, Anran Liu, Ying Li, Wei Wei, Yuanjian Zhang, Songqin Liu
Multifunctional nanoprobes with distinctive magnetic and fluorescent properties are highly useful in accurate and early cancer diagnosis. In this study, nanoparticles of Fe3O4 core with fluorescent SiO2 shell (MFS) are synthesized by a facile improved Stöber method. These nanoparticles owning a significant core-shell structure exhibit good dispersion, stable fluorescence, low cytotoxicity and excellent biocompatibility. TLS11a aptamer (Apt1), a specific membrane protein for human liver cancer cells which could be internalized into cells, is conjugated to the MFS nanoparticles through the formation of amide bond working as a target-specific moiety. The attached TLS11a aptamers on nanoparticles are very stable and can’t be hydrolyzed by DNA hydrolytic enzyme in vivo. Both fluorescence and magnetic resonance imaging show significant uptake of aptamer conjugated nanoprobe by HepG2 cells compared to 4T1, SGC-7901 and MCF-7 cells. In addition, with the increasing concentration of the nanoprobe, T2-weighted MRI images of the as-treated HepG2 cells are significantly negatively enhanced, indicating that a high magnetic field gradient is generated by MFS-Apt1 which has been specifically captured by HepG2 cells. The relaxivity of nanoprobe is calculated to be 11.5 mg−1s−1. The MR imaging of tumor-bearing nude mouse is also confirmed. The proposed multifunctional nanoprobe with the size of sub-100 nm has the potential to provide real-time imaging in early liver cancer cell diagnosis.

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Review of Sample Preparation Strategies for MS-based Metabolomic Studies in Industrial Biotechnology

Publication date: Available online 28 July 2016
Source:Analytica Chimica Acta
Author(s): Tim J. Causon, Stephan Hann
Fermentation and cell culture biotechnology in the form of so-called “cell factories” now play an increasingly significant role in production of both large (e.g. proteins, biopharmaceuticals) and small organic molecules for a wide variety of applications. However, associated metabolic engineering optimisation processes relying on genetic modification of organisms used in cell factories, or alteration of production conditions remain a challenging undertaking for improving the final yield and quality of cell factory products. In addition to genomic, transcriptomic and proteomic workflows, analytical metabolomics continues to play a critical role in studying detailed aspects of critical pathways (e.g. via targeted quantification of metabolites), identification of biosynthetic intermediates, and also for phenotype differentiation and the elucidation of previously unknown pathways (e.g. via non-targeted strategies). However, the diversity of primary and secondary metabolites and the broad concentration ranges encompassed during typical biotechnological processes means that simultaneous extraction and robust analytical determination of all parts of interest of the metabolome is effectively impossible. As the integration of metabolome data with transcriptome and proteome data is an essential goal of both targeted and non-targeted methods addressing production optimisation goals, additional sample preparation steps beyond necessary sampling, quenching and extraction protocols including clean-up, analyte enrichment, and derivatisation are important considerations for some classes of metabolites, especially those present in low concentrations or exhibiting poor stability. This contribution critically assesses the potential of current sample preparation strategies applied in metabolomic studies of industrially-relevant cell factory organisms using mass spectrometry-based platforms primarily coupled to liquid-phase sample introduction (i.e. flow injection, liquid chromatography, or capillary electrophoresis). Particular focus is placed on the selectivity and degree of enrichment attainable, as well as demands of speed, absolute quantification, robustness and, ultimately, consideration of fully-integrated bioanalytical solutions to optimise sample handling and throughput.

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On-line coupling of physiologically relevant bioaccessibility testing to inductively coupled plasma spectrometry: Proof of concept for fast assessment of gastrointestinal bioaccessibility of micronutrients from soybeans

Publication date: Available online 28 July 2016
Source:Analytica Chimica Acta
Author(s): Mónica Alejandra Herrera, María Rosende, Marco Aurélio Zezzi Arruda, Manuel Miró
In-vitro physiologically relevant gastrointestinal extraction based on the validated Unified BARGE Method (UBM) is in this work hyphenated to inductively coupled plasma optical emission spectrometry in a batch-flow configuration for real-time monitoring of oral bioaccessibility testing assays with high temporal resolution. A fully automated flow analyzer is designed to foster in-line filtration of gastrointestinal extracts at predefined times (≤15 min) followed by on-line multi-elemental analysis of bioaccessible micro-nutrients, viz., Cu, Fe and Mn, in well-defined volumes of extracts (300 μL) of transgenic and non-transgenic soybean seeds taken as model samples.The hyphenated flow setup allows for recording of temporal extraction profiles to gain full knowledge of the kinetics of the gastrointestinal digestion processes, including element leaching and concomitant precipitation and complexation reactions hindering bioavailability. Simplification of the overall standard procedure is also feasible by identification of steady-state extraction conditions. Our findings indicate that reliable measurement of oral bioaccessible pools of Cu, Fe and Mn in soybean might be obtained in less than 180 min rather than 240 min as endorsed by UBM. Using a matrix-matched external calibration, limits of detection according to the 3s criteria were 0.5 μg/g for Mn, 0.6 μg/g for Cu and 2.3 μg/g for Fe. Trueness of the automatic bioaccessibility method was confirmed by mass balance validation with recoveries ranging from 87-116% regardless of the target element and sample. Cu was the micronutrient with the highest oral bioaccessibility ranging from 73% to 83% (7.5-7.9 μg/g) for non-transgenic and transgenic soybeans, respectively, followed by Mn and Fe within the ranges of 29-31% (10.8-11.4 μg/g) and 11-15% (8-14 μg/g), respectively, regardless of transgenesis. The proposed kinetic method is proven suitable for fast and expedient estimation of the nutritional value of soybeans and elucidation of the potential effect of transgenesis onto bioaccessible pools of elements.

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Fast and sensitive detection of Ochratoxin A in red wine by nanoparticle-enhanced SPR

Publication date: Available online 28 July 2016
Source:Analytica Chimica Acta
Author(s): Aleksandra Karczmarczyk, Ciril Reiner-Rozman, Simone Hageneder, Monika Dubiak-Szepietowska, Jakub Dostálek, Karl-Heinz Feller
Herein, we present a fast and sensitive biosensor for detection of Ochratoxin A (OTA) in a red wine that utilizes gold nanoparticle-enhanced surface plasmon resonance (SPR). By combining an indirect competitive inhibition immunoassay and signal enhancement by secondary antibodies conjugated with gold nanoparticles (AuNPs), highly sensitive detection of low molecular weight compounds (such as OTA) was achieved. The reported biosensor allowed for OTA detection at concentrations as low as 0.75 ng mL−1 and its limit of detection was improved by more than one order of magnitude to 0.068 ng mL−1 by applying AuNPs as a signal enhancer. The study investigates the interplay of size of AuNPs and affinity of recognition elements affecting the efficiency of the signal amplification strategy based on AuNP. Furthermore, we observed that the presence of polyphenolic compounds in wine samples strongly interferes with the affinity binding on the surface. To overcome this limitation, a simple pre-treatment of the wine sample with the binding agent poly(vinylpyrrolidone) (PVP) was successfully applied.

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