Research Publications (Food Safety)

The first dispersive liquid liquid microextraction scheme followed by liquid chromatography‐post column derivatization for the determination of the antiviral drug – rimantadine – in urine samples is demonstrated. The effect of the type and volume of organic extraction solvent, type and volume of disperser solvent, sample pH, ionic strength, extraction time and centrifugation speed on the extraction efficiency were studied.

The triazine‐based organic polymers@SiO2 nanospheres were prepared and applied as an extraction coating onto stainless steel wires and the wires were filled into polyetheretherketone tube for in‐tube solid‐phase microextraction. Taking polycyclic aromatic hydrocarbons as targets, main factors affecting extraction performance of the tube were investigated through coupling to high performance liquid chromatography.

Determination of methamphetamine is of great importance in the clinical and forensic laboratories because there are low dosages of drugs in the biological media and social problems created due to the methamphetamine consumption. Polymeric carbon based‐nano composites are reasonable candidates for dispersive solid phase extraction method due to facial and affordable synthesis process and high selectivity and sensitivity.

In reversed‐phase LC, tetracycline antibiotics yield broad and asymmetrical peaks, as a result of their ionic interaction with the anionic free silanol groups and metal ion present in the silica‐based stationary phases (commonly derivatized with C18 groups). These frequently encountered difficulties were absolutely eliminated based on dual effect when methanesulfonic acid was employed as an eluent additive.

In this study, an effective speed‐regulated directly suspended droplet microextraction method was developed to condense pesticide residues from teas through dispersive solid‐phase extraction prior to analysis by GC–MS/MS. The extractant was intentionally dispersed into the sample solution in the form of globules through high‐speed agitation. This procedure increases the contact area between the binary phases and shortens the distribution equilibrium time.

In this study, we have developed a method to assess adenosine 5ʹ‐triphosphate by adsorptive extraction using surface adenosine 5'‐triphosphate‐imprinted polymer over polystyrene nanoparticles (412 ± 16 nm) for selective recognition/separation from urine.

A kind of molecularly imprinted polymers modified with biocompatible medium were prepared by suspension polymerization. The obtained hybrid materials were used as the adsorbents for the solid‐phase extraction of aflatoxins B1 in real samples. A structural analog of the target, 6‐methyl‐4‐phenylchroman‐2‐one was used as the pseudo‐template, owing to their lower toxicity and cheaper price compared with aflatoxins B1, and methacrylic acid and glycidyl methacrylate were used as the co‐monomers.

Molecular imprinted polymers prepared by Pickering emulsion method with lignin as stable particle were used as dispersants in matrix solid phase dispersion, followed by ultra performance liquid chromatography‐tandem mass spectrometry analysis to research the degradation behavior of matrine in soil. The molecular imprinted polymers have regularly morphology and uniformly particles. Moreover, the adsorption experiments and the conditions of matrix solid phase dispersion were discussed.

ABSTRACT In this study, quick, easy, cheap, effective, rugged and safe combined with dispersive liquid‐liquid microextraction is developed for extraction of ten pesticides in complex sample matrices of water and milk. In this regard, effective factors of proposed extraction technique combined with gas chromatography‐flame ionization detector were designed, modeled and optimized using central composite design, multiple linear regression and Nelder‐Mead simplex optimization.

Silk fibers were carbonized to develop a biomass carbon material as an adsorbent for solid‐phase microextraction. The surface structure of the carbonized silk fibers was characterized by scanning electron microscope, and the graphitization degree was determined by Raman spectrometer. After the carbonization under high temperature, the orderliness and structural regularity of carbon atoms on silk fibers were promoted.

A novel and porous solid phase microextraction fiber was prepared by quick and simple galvanic displacement reaction and applied to the determination of some polycyclic aromatic hydrocarbons in sunflower oil. The parameters affecting the porosity and thickness of the fiber, and parameters affecting the extraction efficiency including the extraction time, temperature and ionic strength were investigated and optimized.

The biomonitoring of hydroxy polycyclic aromatic hydrocarbons in urine, as a direct way to access multiple exposures to polycyclic aromatic hydrocarbons, has raised great concerns due to their increasing hazardous health effects on humans. Solid‐phase extraction is an effective and useful technique to preconcentrate trace analytes from biological samples.

Ion chromatography coupled with mass spectrometry is an established technique for determination of ionic analytes, however, sophisticated buffer removal equipment is required to eliminate inorganic compounds from the eluate before introduction into the ion source of mass spectrometer. A standard high‐performance liquid chromatography coupled with tandem mass spectrometry setup using an ion exchange column (Metrosep® A Supp 5) is proposed as an alternative approach.

The control of enantiomeric purity and determination of individual enantiomeric drug molecules remains the subject of importance for clinical, analytical, and regulatory purposes and to facilitate an accurate evaluation of the risks posed by them to human health. A large number of pharmaceuticals are marketed and administered as racemates. Etodolac is among such nonsteroidal anti‐inflammatory drugs. Overall literature reports on its enantioseparation are scanty.

The present paper deals with the multivariate optimization of an extraction‐purification strategy for the determination of phytoestrogens (daidzein, genistein, coumestrol, formononetin, and biochanin A) in soy‐based meat substitutes by high performance liquid chromatography with tandem mass spectrometry. For a reliable quantitation of these new concerning compounds in such a complex matrix, recovery and matrix effect must be carefully evaluated.

A systematic Quality by Design approach was employed for developing an isocratic reversed‐phase liquid chromatographictechniquefor the estimation of ropinirole hydrochloride in bulk drug and pharmaceutical formulations. LiChrospher RP 18‐5 Endcapped column (25 cm × 4.6 mm i.d.) at ambient temperature (25±2°C) was used for the chromatographic separation of the drug.

The harmful health effects caused by phthalic acid esters have been supported from the increasing scientific evidence, developing the efficient methodologies to monitor the levels of phthalic acid esters in various foods become especially important from the aspects of human exposure assessment and their migration mechanistic understanding.

We herein presented a mesoporous cellular foam solid‐phase microextraction coating that showed highly sensitive recognition for weakly polarity polychlorinated biphenyls in water samples. The mesoporous cellular foam coater fiber was for the first time prepared by a simple sol‐gel method.

Steroid hormones as endocrine disrupting compounds can interfere with the functioning of hormonal systems of organisms and thus affect the health and reproduction of humans and wildlife. Unfortunately, these types of harmful endocrine disrupting compounds have been found in a variety of environmental samples at very low concentrations. Therefore, a simple, fast, and efficient method for enrichment of water samples is needed.

Xiaojin Capsule, a classic traditional Chinese medicine formula, has been used to treat mammary cancer, thyroid nodules, and hyperplasia of the mammary glands. However, its systematic chemical information remained unclear, which hindered the interpretation of the pharmacology and the mechanism of action of this drug.

ABSTRACT The ripened seeds of Strychnos nux‐vomica L. have been extensively used as herbal medicines in Asian countries. Dihydroindole‐type alkaloids are not only the active constituents but also the toxicants in Strychnos. However, the simultaneous determination of these alkaloids in both crude and processed Semen Strychni is still lacking.

Low potency corticosteroid betamethasone valerate and vitamin‐A tazarotene are used in combination for effective treatment of psoriasis. There is no robust HPLC analytical technique available for simultaneous estimation of betamethasone valerate and tazarotene in conventional and nanocarriers based formulations. The simple, accurate, robust isocratic HPLC method was developed for simultaneous estimation of betamethasone valerate and tazarotene in topical pharmaceutical formulations.

This research deals with development of a stability‐indicating HPLC method for simultaneous determination of amprolium hydrochloride and ethopabate. To the best of our knowledge, no comprehensive stability‐indicating method has been reported for analysis of this mixture. Separation was achieved using Kromasil cyano column with gradient elution of the mobile phase composed of sodium hexane sulfonate solution and methanol. Quantification was based on measuring peak areas at 266 nm.

Driven by the significant need for characterization of the chemical speciation of arsenic in food, this work developed a method for rapid determination of four common arsenic species, namely, arsenite, arsenate, monomethyl arsenic acid, and dimethyl arsenic acid, in vegetables using microwave‐assisted extraction, followed by detection with high‐performance liquid chromatography hyphenated to inductively coupled plasma‐mass spectrometry.

The aim of this work was to develop an efficient method for the selective extraction and analysis of fenoxycarb, a carbamate pesticide, in mussel samples using a molecularly imprinted solid‐phase extraction device. The optimization of molecularly imprinted polymer synthesis was performed using the experimental design under the response surface methodology approach.